%% This list of examples has been alphabetized. Please add your example in the proper place. Thanks!
%% Image selected per Image Pickin' thread: http://tvtropes.org/pmwiki/posts.php?discussion=1479742962043959400
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[[quoteright:350:[[Disney/{{Bambi}} http://static.tvtropes.org/pmwiki/pub/images/thumper_artistic_licesense_biology.png]]]]
[[caption-width-right:350:Who mistook a rabbit for a cat?[[note]]Unlike dogs and cats, rabbits don't have paw pads or button noses.[[/note]]]]

-> ''"This movie is too dumb on too many levels. I mean, why does everything on Earth freeze at night? Wouldn't that kill all the greenery, and the animals? And speaking of animals, why does that eagle adopt Jaden as one of its young, then commit eagle suicide to save him from the cold?! It hasn't figured out how to live in the cold over the last thousand years of being an eagle?! Seriously?!"''
-->-- ''WebVideo/HonestTrailers'' '''review of''' ''Film/AfterEarth''

There are cases where the MST3KMantra certainly applies, especially if the entire world of the work of fiction is pretty crazy and, thus, all bets are off in terms of good science. Therefore, most of the examples below are culled from series who were at least trying to be taken seriously (so please keep that in mind before adding an example on this page).

A subtrope of HollywoodScience. Contrast & compare ArtMajorBiology and ImprobableTaxonomySkills.


+ ArtisticLicenseMedicine
+ ArtisticLicensePharmacology
+ HollywoodEvolution
+ ScienceMarchesOn
+ SomewhereThisIndexIsCrying
++ ArtisticLicenseOrnithology
++ ArtisticLicensePaleontology
++ SomewhereAnEntomologistIsCrying
++ SomewhereAHerpetologistIsCrying
++ SomewhereAMammalogistIsCrying
+++ SomewhereAnEquestrianIsCrying

%% Tropes: %%
* NinetyPercentOfYourBrain
* ABNegative
* AllAnimalsAreDogs
* AllAnimalsAreDomesticated
* AllFlyersAreBirds
* AllGenesAreCodominant
* AmazingTechnicolorPopulation
* AmazingTechnicolorWildlife
* AmbiguousGenderIdentity
* AnatomicallyImpossibleSex
* AnimalGenderBender
* BellyButtonless
* ClamTrap
* CleanPrettyChildbirth
* CloningBlues
* ColdBloodedWhatever
* ConsummationCounterfeit
* CowTipping
* CPRCleanPrettyReliable
* DiurnalNocturnalAnimal
* DominantSpeciesGenes
* EitherOrOffspring
* ElectricJellyfish
* ExplosiveDecompression
* ExtraYExtraViolent
* FlatlinePlotline
* FourLeggedInsect
* GenderEqualsBreed
* HalfHumanHybrid
* HardHead
* HeartInTheWrongPlace
* HollywoodChameleons
* HollywoodGenetics
* HollywoodHealing
** OnlyAFleshWound
** SuckOutThePoison
** WorstAid
* HybridPower
* ILoveNuclearPower
* {{Imprinting}}
* ImprobableTaxonomySkills
* InexplicablyTailless
* InformedSpecies
* InsectGenderBender
* InterspeciesRomance
** HotSkittyOnWailordAction
* LongestPregnancyEver
* MagicalDefibrillator
* MisplacedVegetation
* MisplacedWildlife
** PolarBearsAndPenguins
* MisterSeahorse
* MonstrousGerms
* MorePredatorsThanPrey
* NoBiochemicalBarriers
* NoDeadBodyPoops
* NoPeriodsPeriod
* NoisyNature
* NonhumansLackAttributes
* NonMammalMammaries
* NonMammalianHair
* NuclearNasty
* OneDoseFitsAll
* OnlyPointTwoPercentDifferent
* OstrichHeadHiding
* PatchworkKids
* PerpetualMolt
* PerplexingPearlProduction
* PoisonIsCorrosive
* PrehensileHair
* PsychoElectricEel
* RandomSpeciesOffspring
* RapidHairGrowth
* RemovableShell
* RibcageStomach
* ShrunkenOrgan
* SingleSpecimenSpecies, aka EcologicallyImplausible
* SmashedEggsHatching
* SpontaneousGeneration
* StockBeehive
* StockFemurBone
* SuperPersistentPredator
* TaxonomicTermConfusion
* ToServeMan
* ToothyBird
* TypicalCartoonAnimalColors
* UltimateLifeForm
* UnstableGeneticCode
* VegetarianCarnivore
* WhaleEgg
* YouGottaHaveBlueHair

!!The following '''examples''' do not fit any subtropes:


* In an [[http://www.youtube.com/watch?v=XMoRw8IKcvk H2OH commercial]], the narrator voice comments how cool it is that nature gave spikes to the hedgehog, instead of you (human). In the video, though, the guy ''shoots'' spikes all around. It's said that porcupines can shoot their quills -- porcupines are not hedgehogs, however, and the popular belief is in fact false. Porcupines may have their spines dislodged while swinging their tails around because the spines are very loosely attached to the porcupine so that they'll come out once they've been lodged in another creature's skin; however, they don't deliberately shoot their quills at a target. They're much more likely to reverse into your leg and fill it with hooked barbs.
* Yellow, the peanut M&M from [[Advertising/MAndMs the candy commercials]], messes up when he and Red show off their muscles. Yellow boasts "Check out my adenoids!", but adenoids are tonsils, not muscles. Probably more of a GeniusBonus since neither of the M&Ms ('''especially''' Yellow) have ever been portrayed as incredibly smart.
* Lots of ads and other kinds of artistic portrayals show "parrots" that don't exist in nature, with bizarre coloration, patterns, etc. Oh well. But even depictions which were obviously done with a good attention to detail, including real-life parrot coloration, feather layout, anatomy, etc. still often mess up the feet. A very large fraction of all parrot artwork gives them "chicken feet" (with three toes facing forward, one facing back) instead of real parrot feet (which have two toes forward, two toes backwards). Corona Beer ads are especially bad about this. The same problem often crops up in depictions of toucans, woodpeckers, cuckoos, and roadrunners, which also like parrots have [[http://en.wikipedia.org/wiki/Dactyly#Zygodactyly zygodactyl]] feet.
* Most commercials for hair care products use words like "nourishment" or "healthy hair." One commercial years ago even went so far as to call hair "a living, breathing part of your body." Too bad that the part of the hair being "treated" is biochemically dead. The only part that's actually alive is underneath the skin, in the follicle.
* There's the "oxygenated water" thing. Drinking water with more oxygen packed into it is good for you, right? Well, only if you had fish gills in your stomach. If your stomach and intestines could perform that sort of gas exchange, Coke and Pepsi with their carbon dioxide would be deadly poison. Lungs do that function excellently, thank you.
* There's one vitamin commercial that claims that it helps repair your "cell ''walls''", a feature not found in mammalian cells. Even if they're just trying to put "cell ''membrane''" in simpler terms, those terms only ''exist'' in biology (nobody knew about the things to name them before the invention of the microscope), so their technical usage is their only correct one.

[[folder:Anime & Manga]]
* A majority of anime portrays octopi and squids as having their siphons in front of their heads as if they are some kind of sucker-like mouth. In reality, the siphon is placed on the side of the body.
* A major plot point in ''Anime/{{Doraemon}}'' involving Sewashi changing the past by sending Doraemon back to 20th century to improve Nobita's future, resulting in his great-great-grandmother being changed from Jaiko to Shizuka. He demonstrates that no matter who Nobita will marry, he will always be born which is not possible due to his 1/16 gene is different, thus, he will cease to exist. The fact that this doesn't occur in any of the mangas or adaptation so far suggest that there is something that Sewashi didn't tell or either the authors just didn't think about this.
* In-universe example in ''Manga/AxisPowersHetalia''. Its most prominent female character Hungary used to think she was a boy. And she thought that penises grow as you age, which would "explain" her...lack of one. ''And'' she laughed at Prussia for "not knowing."
* In ''Manga/BakiTheGrappler'', in addition to all the other insane/biologically impossible things that fighters do, Shinogi Kanno can rip out nerves with his bare hands. In a fight with Baki, he blinds him by ripping out his optic nerves; apparently unlike all other humans, his optic nerves are located in his neck. Baki then temporarily repairs them by knotting the nerve endings. Of course, he makes a full recovery. Somewhere, a neurologist is weeping.
* {{Handwave}}d in ''Franchise/{{Digimon}}'', anything impossible that a Digimon (or the Digital World) does is explained away by saying "they're just data".
* ''Manga/LoveHina'':
** Ken Akamatsu seems to have been blindsided by myths about eyesight. Supposedly, Naru 'ruined her eyes' by studying so much for her entrance exams, and towards the end, Keitaro has developed night blindness, unstated but implied to be from going on so many digs with Seta. While these things are possible, they would require our fun couple to do most everything by dim candle-light, never get enough Vitamin A in a modern culture, and seems a combo of somewhat realistic biology and old wives' tales. Maybe this was meant to symbolize their blindness about their mutual feelings, but genetics also plays a huge role in eyesight.
* ''Manga/{{Naruto}}''
** Naruto was born the day of the Demon Fox attack. But at the time of the sealing he is shown without an umbilical stump. That usually doesn't happen until ten days after birth.
** Surgery in ''{{Manga/Naruto}}'' tends to work a bit like LEGO with anyone being able to put pieces of other people onto themselves with minimal effort. Eyes are repeatedly removed and given to other people. In once case a character manages to implant someone else's eye in his socket while sprinting. Another character managed to pull out his own eyes and put them into someone else's head without that other person noticing what had happened.
** The cells of Hashirama Senju can apparently just be implanted willy-nilly into anyone for various effects. Madara Uchiha discovered their power when, for some reason, he used pieces of Hashirama's flesh to patch his wounds.
** The same thing happens with Orochimaru. Late in the story [[spoiler:Kabuto]] injects Orochimaru's blood into his body and it gradually infests his body like a cancer while also giving him Orochimaru's abilities.
** Plenty of characters suffer significant burn injuries, but only to their skin and body. Their hair and clothing ([[ClothingDamage usually]]) remain intact.
* ''Manga/TsubasaReservoirChronicle'' features, to make a long MindScrew short, a MyOwnGrampa situation[[note]] original, clone, reincarnation of clone who is father to original and has same DNA as last incarnation[[/note]] where all involved have the same DNA, despite the presence of a non-blood-relation mother. [[JustifiedTrope This may be because of]] [[spoiler:the laws of reason, i.e. cause and effect, falling apart]].
* When Tetsuo from ''Manga/{{Yuureitou}}'' is unable to use testosterone for several weeks, his voice starts reverting to a more feminine pitch. In real life going off testosterone doesn't do that to trans men. It might affect other parts of your body, however your voice changes are permanent.

[[folder:Board Games]]
* In ''TabletopGame/TheWorstCaseScenarioSurvivalGame'', a game about answering questions, the "correct" answer to a [[http://boards.straightdope.com/sdmb/showthread.php?t=360418 question about sky diving]] is that ''sky divers breathe though their skin.'' And this game is supposed to be accurate!

[[folder:Comic Books]]
* In the ''ComicBook/BuffyTheVampireSlayer'' miniseries "Viva Las Buffy", in which our heroine travels to Las Vegas, the villains are two twins joined at the hip: the man's a vampire, the woman's a mortal with deadly aim. One problem: their joining was so minor (both had full limbs and organs), any sane doctor would have separated them at birth -- and conjoined twins are identical and not fraternal and would therefore necessarily be of the same sex. This being ''Buffy'' (and as such, anything can happen), [[AWizardDidIt a wizard probably did it]].
* In ''Comicstrip/CalvinAndHobbes'', Calvin's mother once told him not to take Hobbes into a lake the family was camping by because "tigers don't swim very well".
-->'''Hobbes:''' Frankly, I'm not sure your mom knows so much about tigers.
** Although Calvin's mom probably thinks of Hobbes as a stuffed toy.
* ''Comicbook/{{Daredevil}}'' villain ComicBook/TheKingpin claims that only 2% of his body mass is fat. While it is possible for someone to have the type of "solid muscle" build that he has, such a claim is impossible.
* ''[[http://www.gutenberg.org/etext/1593 How to tell the birds from the flowers]]. A manual of [[NinjaPirateZombieRobot flornithology]] for beginners'' by R.W.Wood parodied semiliterate "botanics" books:
-->Some are unable, as you know,
--> To tell the Crocus from the Crow;
-->The reason why is just be-caws
-->They are not versed in Nature's laws.
* Nearly the entirety of issues #3 and #4 of ''ComicBook/{{Marville}}'' is loaded with completely asinine science, with a particular focus on evolution. All to set up a joke that Comicbook/{{Wolverine}} was the first human, evolved from an otter.
* InUniverse example in ''ComicBook/MyLittlePonyFriendshipIsMagicIDW'': Sweetie Belle thought that teeth grew back. They do, but only ''once'' in horses—the baby teeth are replaced by the permanent ones, just like for humans.
* ''Comicbook/SwampThing'':
** In the WhamEpisode, it is revealed that [[spoiler:Swamp Thing is actually a plant, not a transformed human]]. Fair enough (stranger things have happened in the DC Universe). The thing is, we're told that his memories were transferred to [[spoiler:the plant]] in the same way that [[http://en.wikipedia.org/wiki/Planarium planarian]] worms can learn how to run a maze by ''eating other planarians that solved the same maze''. While it is, admittedly, a fantastic idea for sci-fi writers to play with, it's too bad the planarian worm experiment from 1962 was faulty to begin with and [[ScienceMarchesOn has since been discredited.]] The new worms in the maze were actually following the slime trails left by the old ones, rather than relying on transferred memories. Placed in a fresh maze, they performed no better than the old ones. (Funnily enough, the scientist saying this in the story is, at his best, not quite right in the head. And later, Moore ''does'', in fact, reveal that AWizardDidIt.)
** The conclusion to the Woodrue storyline has Swamp Thing pointing out that, without animals, there'd be nothing to turn oxygen into carbon dioxide for the plants to use. Fungi are perfectly capable of carrying out this task, as are ''the plants themselves'' when they switch from daytime photosynthesis to nocturnal aerobic respiration.
* The explanations for ''Franchise/{{Superman}}'''s abilities combine Artistic License -- Biology with ArtisticLicensePhysics to a staggering degree, raising such questions as "How does he cut his hair?" and "How does his sperm not drill through Lois Lane's flesh like a sandblaster?" Some stories actually attempt to answer some of these questions, though not the latter[[note]]though John Byrne's take on Superman defined his invulnerability as being an almost-skintight telekinetic forcefield. Not only did this allow his cape to become dramatically tattered, presumably his *ahem* bodily materials would become normal once they passed outside the field too[[/note]].
* ''ComicBook/XMen''. While they're supposedly "The next step in human evolution", a claim which in and of itself shows a lack of understanding of the concept of evolution, absolutely ''none'' of their powers work without liberal use of the MST3KMantra. Also, the fact that ''one'' mutated gene can apparently do so much, and the constant claims that mutants are not humans show a clear misunderstanding of what the word "mutation" even means. The vast majority of Mutants have absolutely ludicrous powers, {{handwave}}d by [[Main/AWizardDidIt The Celestials]] inserting the x-gene in humanity millennia ago, known as the celestial seed.
* Creator/WarrenEllis: After he explained the difference between normal and artificial mutants (or were they mutants from alternate reality? Probably both) in his first ''Astonishing X-Men'' story, people at Scans Daily pointed out that genetics don't work that way. Ellis admitted his mistake.
** When Ellis wrote ''Iron Man: Extremis'', he explained the eponymous magic bullet (a single injection which would turn ordinary mortals into supermen) as a "Data package contained in a few million carbon nanotubes, injected directly into the brain". The information package would then rewrite the repair center in the brain -- that is, the part of the brain which keeps a complete 'map' of our organs and functions. "The brain is telling the body is wrong"... and it compliantly changes according to the Extremis instructions. Perhaps needless to say, there is no "repair center" (although the "sensory homunculus" seems a little bit like what is described). Later writers {{retcon}}ned Extremis into a viral package, which is at least borderline believable.
** And in ''ComicBook/{{Supergod}}'' it is a point that 'mushrooms only grow on dead things'. Which, well, they do not.
** And then there was ''Ultimate Extinction'' where Reed Richards (of all people) explained how a Big Bang comes from 'a mass of volatile gases' which he then proceeded to set off with a massive nuclear warhead.
* Franchise/{{Batman}}'s physical capabilities are supposedly natural, without any artificial or supernatural enhancements, but his feats are greatly embellished. For example, he's able to bench press 1,000 lbs ''and'' fight for 28 hours straight. Fighting for 28 hours straight is basically impossible for the human body, and much more-so if you've got the oxygen-sapping physique of a power-lifter. Consider that top professional fighters carefully regulate their training to enter the ring at their absolute physical peak, yet still need to rest every 3 to 5 minutes to fight at their maximum capacity.
* In ''ComicBook/WhiteSand'', on a TidallyLockedPlanet, people of [[EndlessDaytime Dayside]] have pale skin, while people of [[AlwaysNight Darkside]] have black skin, whereas it should be the other way 'round, for obvious reasons. It's explained by WordOfGod by Darksiders having their own "dark" source of light that mainly emits UV radiation.

[[folder:Fan Works]]
* Subverted in the ''WesternAnimation/DannyPhantom[=/=]WesternAnimation/{{Gargoyles}}'' crossover, [[http://www.fanfiction.net/s/3444790/1/A_Wish_Your_Heart_Makes "A Wish Your Heart Makes."]] Titania gives Vlad a vision of what his life might have been like if he had stayed friends with Jack and Maddie instead of turning evil. This leads to Vlad becoming Danny's biological father to prevent him from being born with hemophilia (Jack and Maddie had just discovered that Maddie and Jazz were carriers for it). Once Vlad wakes up from the vision, he reminds Titania what almost anyone who knows anything about hemophilia would have already noticed: because it's carried on the X chromosome, any child of Maddie's would have had the same chance of inheriting it no matter who the father was. Titania admits that she included that error on purpose so Vlad would know for sure that it really was AllJustADream.
* ''WesternAnimation/MyLittlePonyFriendshipIsMagic'':
** Fanfic writers generally tend to forget that horses can't vomit -- although, to be fair, ''so does the show'', given the many instances of ponies vomiting (such as in response to [[Recap/MyLittlePonyFriendshipIsMagicS1E4ApplebuckSeason disgusting pastry]]). [[http://www.fimfiction.net/story/322876/wait-horses-cant-vomit Ironically, this very trope inspired a fanfic in response to refute this: that Equestrian horses and Earth horses are two separate animal species with different biologic limitations]].
** In second chapter of ''Fanfic/AKingdomDivided'', Vinyl Scratch has her bloodtype tested with "human" [=AB0=] kit. Real-life horses have over thirty different bloodtypes, which would require completely different set of antibodies.
** Whenever a birth is portrayed, it is often presented with the same sort of dramatic tension that human births are often portrayed with ([[ScreamingBirth complete with the pain labor causes]]). The issue with this is that, due to their quadrupedal body design, horse births are usually [[OutGivingBirthBackInTwoMinutes very quick and easy]] (a necessity for prey animals to avoid detection by predators). In fact, humans are something of anomaly among mammals for the difficulty of our births, a direct result of the shifting of organs and tubing during the shift to bipedalism altering the path a baby takes to exit the mother's body and making it much more likely for things to wrong -- quadrupeds would simply not have these issues. Further, few fics are accurate enough to portray equine pregnancy as eleven months (as opposed to a human's nine months).
* In ''Fanfic/TheDarkerKnight'' Batman's batarang hits "Too-Face" in non-vital organs... like his liver and intestines.
* The fanfic ''Fanfic/FullMetalDragon'' doesn't even have to start before this happens. Jake's mom had an affair while she was still pregnant with him. resulting in two infants. Jake stayed with them while the other child went with his father, Hoenheim of Light. While this ''is'' possible (it's called [[http://en.wikipedia.org/wiki/Superfetation superfetation]]) it's also ridiculously rare -- there have been only ten known human cases.
* In ''Fanfic/LightAndDarkTheAdventuresOfDarkYagami'', Dark shoots and kills Watari on his way out of the "Whammy" house. Watari returns six chapters later, having been revived by CPR -- even if he hadn't been killed, CPR could not have saved his life.
* In the ''Literature/PercyJacksonAndTheOlympians'' fanfiction ''Fanfic/MoonDaughter'':
** The author believes that kissing causes you to lose your virginity.
** And this line: "I kicked him in teh cocanuts so he could never conceve."
* Somehow, ''FanFic/MyImmortal'' confused ''magic'' with "advanced biology" when the protagonist was narrating about what is ostensibly transmogrification.
* Invoked in universe by Elizabeth in ''FanFic/TheNewRetcons'' to try to explain why [[spoiler: she and her husband (both light haired) produced a dark haired baby. Unfortunately for her, Anthony paid attention in biology, and that coupled with the baby's darker skin tone tipped him off that the baby's not his]].
* In ''Fanfic/ShinraHighSOLDIER'' by Sephirothslave, Hojo ends up pumping ten 500 ml (5 liters/1.32 gallons) mako injections into his body one night. The average normal adult has roughly 5 liters (1.3 gallons) of blood in his body, meaning that he basically replaced almost all his blood with mako.
* ''The Anime/SailorMoon Legend of Zelda'':
** Creator/DakariKingMykan gives us this gem, where a character seems to have biology and geology a tad confused:
-->''Melvin was most outraged by that. "How can you girls say that?!?" he spat. "Biology is all around us, the singular sciences of how our glorious Planet-Earth is formed and runs.''
** Moments later:
--->"Now, I understand your teacher has had you investigating the science of sound."
* Also from Creator/DakariKingMykan, in one chapter of ''Fanfic/MyBravePonyStarfleetMagic'', Fluttershy has to go to the hospital, because of her appendix. Ponies don't have one. [[CreatorsApathy Mykan admitted he knows that, but he was too lazy to think up something else, to make Fluttershy sick.]]
* ''[[https://www.fanfiction.net/s/10781990/1/the-man-with-two-souls the man with two souls]]'', a ''WebAnimation/{{RWBY}}'' fic, depicts Jaune's evil split personality as being physically stronger and more martially skilled than him. Despite sharing the same body.
* Creator/HansVonHozel:
** In ''The Raven'', the titular raven is being hunted for its ''fur coat''.
** Also, the ''Series/{{Glee}}'' fanfic involves a banana forest growing as a result of ProducePelting. Edible bananas have no seeds.
* A Fanservice-crossed-with-disturbing ''Franchise/TheLordOfTheRings'' fic featured the MarySue sustaining the Fellowship when they ran out of food by ''breastfeeding'' them. Human females do not produce enough milk to feed nine adult males at once. Someone on a badfic-sporking community pointed out that they'd do better to kill and eat her. Even if the MarySue could produce enough milk, human breast-milk has very little nutritional value to a human older than, say, 8 years old (this being the absolute upper limit).
* Many a KidFic or piece of fanart focuses on the child or children of two male or female characters. This could be {{handwave}}d away as being due to adoption or, in the case of the latter, artificial insemination -- but almost all of them either draw or describe the child as being a {{patchwork kid|s}}, leading to the question of how exactly the boy or girl bears such a close resemblance to their fathers/mothers. Some jokingly refer to this phenomenon as "[[AWizardDidIt magical lesbian spawn]]".
* [[MisterSeahorse MPreg fics]]. Sometimes {{hand wave}}d by AWizardDidIt sometimes... not. The so called real biological justifications range from babies delivered anally to the character having a uterus. The latter example ignores the lack of ovaries, fallopian tubes, a menstrual cycle or any relevant opening with which to eject the baby. There's Artistic License Biology and then, there's this.
* There is a [[ArchivePanic rather prolific]] [[http://www.fanfiction.net/u/1891678/LordryuTJ author]] on Fanfiction.net who seems to believe that the male and female genitalia differ InNameOnly.
* There is one ''Harry Potter'' fanfic that places Draco's penis at a minimum of ''42 inches long''[[note]] IT COULD GET ON DISNEYLAND ATTRACTIONS BY ITSELF[[/note]]. The quantity of blood required to get something that long erect would cause the rest of the body to die from lack of blood instantly. He'd have it [[GroinAttack dragging against the ground wherever he goes]]. He better be asexual, or else he's going to live a life of forced celibacy, or have to romance giantesses.
* There's a particularly bad ''WesternAnimation/{{Sixteen}}'' fic where the author states that Niki's mary sue twin is such because doctor's put her dad's '''eggs''' in Niki's mother.
* At least two YaoiGenre FanFic / SlashFic featured someone with an ''anal hymen,'' and ''many'' others have featured pain/bleeding/difficulty in penetration as somehow part of normal anal sex between men. The anus does ''not'' have a hymen, as anyone who has ever had a bowel movement should understand. Also, pain beyond slight burning or difficulty penetrating means that something is wrong (usually, the receiver isn't relaxed or prepared well enough if either happens), and bleeding means something is really, seriously wrong that may require immediate medical treatment and means STOP RIGHT NOW (''at best'' a bumped hemorrhoid or the top has too-long/sharp fingernails, at worst something has been torn or ruptured or cancer is present)
* This is averted in the FanFic/Gensokyo20XX series with Ran's suicide attempts and they were noted to have failed because she probably wasn't cutting in a way in which that hit the major arteries and the fact that she did so in the snow, the cold of which caused her blood vessels to pull back.
* Zigzagged in ''FanFic/SonicXDarkChaos''. Most of the biology behind the Shroud and the resulting BodyHorror they cause on their victims are physically and anatomically impossible. It doesn't make them any less [[NauseaFuel gross]] and [[NightmareFuel terrifying]] though, and is entirely done for RuleOfScary. Lampshaded by Chris in the rewrite, who states that everything about the Shroud goes against every biological law as humans understand them, and it's the reason he's utterly terrified of them.
* In ''[[http://cartoon.adult-fanfiction.org/story.php?no=600094952&chapter=2 The Lion Guard]]'', the eponymous lions have hands. And fingers. This defies both real biology and [[Disney/TheLionKing the source material]], in which lions have very obvious ''paws''.
* Several ''Anime/{{Inuyasha}}'' feature Kagome and/or Sango going into heat. Humans don't go into heat; they have a menstrual cycle. Similarly, some stories have a demon being able to smell that they/they're mate is pregnant as soon as a few minutes after having sex.
* An old FanFic from Inkling Studios called Insanity has the villain get burned by a lighter and receive '''third-degree burns.'''

[[folder:Films -- Animation]]
* Jenna from ''WesternAnimation/{{Balto}}'' is a red Siberian Husky. While "red" Siberian Huskies do exist, they're more of a brownish tone than a bright red. Jenna's fur invokes HeroesWantRedheads more than the actual colour does.
* ''Disney/{{Bambi}}:''
** Thumper is depicted with paw pads, something real rabbits do not have. Also, his nose is drawn looking more like a cat's nose than the "V"-shaped noses actual rabbits have.
** The Great Prince is shown with fully-grown antlers in spring, summer and winter, even though deer shed their antlers and grow new ones every year.
** Bambi gets "twitterpated" in the spring, but the mating season of white-tailed deer is in the autumn.
* It seems that the bulls and cows of ''WesternAnimation/{{Barnyard}}'' and its spinoff ''WesternAnimation/BackAtTheBarnyard'' are separate species. Case in point, Otis is a [[AnimalGenderBender male cow]] and one episode has a female bull.
* Going past all of the usual dragon examples that would apply to the beast from ''WesternAnimation/{{Beowulf|2007}}'' (like wingspan), how does a heart that can fit in a man's fist pump blood through the body of a [[AttackOfThe50FootWhatever seventy foot long]] [[IfItSwimsItFlies flying and swimming]] reptile? Never mind that a heart in the neck protected by tracing paper is a bad idea anyway. Blocking the trachea and being easily ripped out are not desirable traits in a heart. However this is a human-demon hybrid, so there is an element of the supernatural at work which can circumvent the biological impossibilities.
* ''WesternAnimation/FindingNemo'':
** Barracuda don't have much of a taste for eggs. They prefer live prey. That said, it's possible the barracuda was aiming for Coral and destroyed the eggs by accident.
** Also, clownfish don't keep their eggs in caves for the very reason that happened in the movie. To keep their eggs safe from anything that would eat the eggs, they lay them on a flat part of the sea anemone where egg-eaters can't get them. But then again, you need some reason to get the plot going...
** The interior of the whale's throat is too large. While blue whales have a gigantic '''''mouth''''', their throat is tiny and unable to swallow anything larger than a beach ball (though that is still enough to swallow Marlin and Dory.
** They also have respiratory and digestive traits completely separated, you know, so that they don't unintentionally [[spoiler:sneeze fish out of their blowhole]]. [[HollywoodDarkness And where is the light inside its mouth coming from?]]
** Chuckles, the gift fish who was killed by Darla, looks like a goldfish. Which live in freshwater. The other Tank Gang fish are saltwater fish. You can see where this is going.
** None of the sea turtles seem to worry about having to breathe. They also don't travel in flocks, [[RuleOfCool but this was intentional]].
** Sea turtles don't live anywhere near 150 years; that honor belongs to tortoises. Their expected lifespan is still quite impressive at 80 years.
** Clownfish do live in anemones but they also live in harems dominated by one male and one female, with a lot of non-productive males in the rest. When the dominant female dies, the dominant male undergoes a GenderBender and becomes the new dominant female. Clownfish will also reproduce with their relatives in times of emergency. This particular tidbit has raised eyebrows at the choice of clownfish for the film.
** Interestingly, a featurette on DVD addresses the whole Artistic License issue. An animator relates a story of one of their consultants talking about the biological inaccuracies in their final fish designs. The animator replied, sheepishly, "Well... in real life they don't ''talk'' either, so..."
* There seems to be some inconsistency as to whether Brutus and Nero from ''Disney/TheRescuers'' are alligators or crocodiles. If they are alligators (as the concept art for the movie implies) then their teeth are incorrect, being shown protruding instead of covered by the upper jaw.
* ''WesternAnimation/IceAge'':
** The Dodos are in fact extinct, but they didn't die out during the Ice Age. They were wiped out by man very quickly after discovering the remote island of Mauritius were they used to live. Not mainly for food (they tasted awful), but simply as some sort of sport... They were in no way "too dumb to live" as portrayed in the movie, but just evolutionary unfit for the challenge by naked apes who, after a long sea travel, would see clubbing fat flightless birds as appropriate entertainment. (Of course, [[http://en.wikipedia.org/wiki/Surplus_killing many predators will kill prey animals even if they're not currently hungry]], possibly because having carrion on hand that you recently had no use for can be quite helpful. Humans are just the only ones that guilt-trip over it.)
** There is a creature which is identified as an aardvark, but though it has the ears of an aardvark, it has the bushy tail of a giant anteater, and its snout is weirdly elongated to be reminiscent of an anteater (not an aardvark), but that animal would have a tiny mouth at the tip of its snout, whereas the cartoon critter has its mouth at the base.
** Scrat the proto-squirrel has huge saber-like canine teeth. Being rodents, squirrels -- even prehistoric ones -- don't have canines at all. Although the authors have said in an interview that it was PlayedForLaughs. Later crosses into AccidentallyCorrectWriting since [[http://www.npr.org/blogs/thetwo-way/2011/11/03/141997834/scientists-unveil-fossil-of-saber-toothed-squirrel-that-lived-among-dinos a later discovered prehistoric mammal was indeed squirrel-like]], [[ScienceMarchesOn and did indeed have fangs]]. It was not a rodent though, and lived in the ''Mesozoic'', not in the Cenozoic, much less the last ice age.
** Sid and the other sloths walk perpetually upright and flat on their feet (sloths walk on all fours and on the sides of their feet, not unlike an anteater), and have heads shaped like a ''hammerhead''. They also have noses more like a dog's, though it's most likely ground sloths had pig-like noses since both 3-toed and 2-toed sloths have them.
* ''WesternAnimation/TheLegendOfTheTitanic'':
** The dolphins jump as high as the deck of Titanic and manage to float in the air for a short amount of time by ''flapping their flippers''.
** The unrealistically large octopus which has a dog's nose, and has to take a breath before it goes underwater.
* ''WesternAnimation/SpiritStallionOfTheCimarron'': Spirit is shown leading the herd, something that only mares do. A stallion stays at the very back, herding stragglers.
* ''Disney/TheLionKing'':
** Nala's father should logically be Mufasa or Scar, making her related to Simba, who became her mate. In an early script Nala was [[KissingCousins Simba's cousin]], but that was removed in the ''King of the Jungle'' stage. According to ''WesternAnimation/TheLionGuard'' her father is an unknown, possibly rogue, male.
** Rafiki is a mandrill with a tail of a baboon and ''living in the savannah instead of in the forest''; Zazu is a red-billed hornbill that is blue instead of brown; Pumbaa is a reddish brown warthog that looks more like a big-headed pig than a warthog; Timon is an always-bipedal meerkat with human-like teeth and that says "Ugh, Carnivores!" even though he belongs to the order Carnivora as well; the spotted hyenas (''Crocuta crocuta'') that [[MixAndMatchCritters bear some resemblance]] with striped hyenas (''Hyaena hyaena''), with grey hair, large shaggy black manes, black ears and low-hanging head.
** Lions in this film have larger dew claws than in RealLife, which they can use as thumbs to make human-like hand gestures. It's the most conspicuous with Scar, who [[MinionMaracas grabs Banzai by the neck]] during his VillainSong.
** Given that they are very close to the same age, realistically, Scar and Mufasa would have been kicked out of their natal pride by their father at or around the same time, and worked ''together'' to take over a pride. Which they would then lead and father cubs for ''together.'' The same would have happened to Simba, [[spoiler:had Mufasa lived.]] But, that doesn't make for a very good Disneyfied version of ''Theatre/{{Hamlet}}'', now does it?
** In general, the pride operates much closer to a human monarchy than an actual lion pride, with a clear line of succession, a monogamous ruling couple, and even royal advisers and arranged marriages.
** The hyenas bark and whine like dogs. In real life, hyenas are more closely related to cats, and normally make whooping or giggling noises.
** A relativity small thing, but none of the cubs in either of the movies seem to be part of a litter. Though lionesses typically have small litters (usually just two or three cubs at a time) and having a single cub is certainly possible, to have all of these cubs being single births is quite bizarre. Lions also tend to have litters within months of each other, but Kiara was the only cub in her pride and her parents were the only two when they were young. Extended media tries to fix this, such as ''Literature/TheLionKingSixNewAdventures'' introducing Chumvi and Kula as Nala's childhood friend and ''The Lion Guard'' having Kiara be friends with two cubs as well, but the characters end up looking like [[RememberTheNewGuy random additions]].
** Lion cubs lack the rosettes that actual young cubs have. The sole exception is Kion from ''The Lion Guard'' (who is actually too old for them). Concept art shows that Simba originally had rosettes, but in the final product he lacks them.
** Newborn lion cubs are depicted as rather large and with their eyes already open, in contrast to real cubs who are smaller and are born with their eyes closed.
** Simba and Nala are monogamous and only have one cub (two cub ''The Lion Guard''). In a real pride, Simba would mate with all the females. It's never specified who are the fathers of Nala or the other other Pridelander cubs.
* Marty from ''WesternAnimation/{{Madagascar}}'' is treated as if he's having a HollywoodMidLifeCrisis at age ten. While it's true that wild zebras have a life expectancy of twenty-five, captive zebras have a life expectancy of ''forty''.
* ''Disney/{{Pinocchio}}'':
** Jiminy Cricket bears very little, if any, resemblance to an actual cricket. To be fair, however, Jiminy was originally depicted as an actual (that is, less anthropomorphized) cricket with toothed legs and waving antennae. But Walt wanted something more likable. So he assigned animator Creator/WardKimball to redesign the cricket. Kimball whittled away at any and all cricket-like appendages until Jiminy became, in Kimball's words, "a little man with an egg head and no ears. And the only thing that makes him a cricket is because we call him one."
** Monstro the whale resembles a sperm whale, but has a head much too wide and teeth on both jaws, when real sperm whale have laterally-flattened heads and only have teeth on their very thin lower jaw. He also has belly lining, which is a trait of baleen whales. He is also seen sleeping at the bottom of the ocean. Whales don't sleep that way, or else they would drown. Although it's eventually revealed he's just pretending to sleep so he can ambush passing schools of fish.
* ''Disney/ThePrincessAndTheFrog'':
** The alligators that attack Tiana and Naveen are depicted with interlocking teeth like crocodiles. It gets jarring in that Louis has his lower teeth hidden when he closes his mouth, like a real alligator.
** When they're frogs, Tiana is smaller than Naveen, more or less proportional to human males and females. In most real-life frog species, the female is larger than the male.
* Combine that with ArtisticLicenseHistory: In Creator/RankinBassProductions' ''[[WesternAnimation/SantaClausIsCominToTown The Easter Bunny Is Comin' to Town]]'', one music segment has the chickens tell a story [[BigLippedAlligatorMoment in a song]] that makes fun of the riddle of "chicken or the egg": They explain that "the chicken came first" by retelling Literature/TheBible story of [[TheGreatFlood Noah's Ark]], and comparing the riddle to who came first: "[[NurseryRhyme the pussycat or the fiddle]]", "the [[http://en.wikipedia.org/wiki/Fountain_of_Youth Fountain]] or [[http://en.wikipedia.org/wiki/Juan_Ponce_de_Le%C3%B3n Ponce de León]]", and "[[BreadEggsMilkSquick the cow or]] [[http://en.wikipedia.org/wiki/Catherine_O%27Leary Mrs. O'Leary]]". ScienceMarchesOn: Scientists now think the dinoid oviducts had to evolve to produce the proper egg before the chicken('s ancestor) could be hatched. Technically, the chicken did evolve first.
* In ''WesternAnimation/{{Sahara}}'', each snake sports a unique scale color and patterning unlike anything exhibited by real snakes. In Eva's case, her pattern consists of a row of ornate flowers imitating the style of Mehndi body art, also known as henna[[https://en.wikipedia.org/wiki/Mehndi]].
* On ''WesternAnimation/StrawberryShortcake'', the Purple Pieman apparently literally never dreamed throughout his life up until ''The Sweet Dreams Movie'' — that's why he wants to "steal a little dream of yours." That's biologically impossible — people who don't dream go insane and eventually die.
* ''Disney/{{Tarzan}}'':
** Tarzan's often able to win over others' sympathy through his eyes, including the gorillas. In reality, gorillas do not like direct eye contact, perceiving it as a challenge. Locking eyes with one of them is demanding a fight.
** A human walking on his knuckles as Tarzan does would be extremely painful, and cause severe damage to the bones in the hands. Gorillas get away with this due to thicker knuckle bones and arms longer than their legs, unlike humans. As he's spent most of his life walking on all fours, Tarzan's pretty fortunate that his back isn't wrecked as well.
** Albeit with great difficulty, Tarzan does manage to physically hold Kerchak back to stop him from attacking Jane. Though it is difficult to gauge their strength with any precision, a silverback male gorilla usually tips the scales at about 400 pounds and is many times strong than any human. A human attempting to take on an angry silverback in real life would literally be crushed in a heartbeat.
* ''WesternAnimation/LeoTheLion'': What's ''not'' wrong with the animals in this film? Well, here are a few examples.
** Leo's pride shows five male lions running the pride, when real-life prides have one or two males in charge. Five male lions in charge is begging for lots of infighting for power.
** As lions are obligate carnivores, they can't choose to be vegetarians. Leo's body frame, which the movie tries to say is good because of a vegetarian lifestyle, is less sleek and more emaciated.
** Due to the way embryos are formed, it'd be impossible for baby elephants' tails to be connected at birth.
** Leo and Uncle Lope the antelope force a female zebra to give milk to the baby animals. She's shown to have nipples on the stomach (more like a dog or a cat) as opposed to having an udder between the legs like real-life zebras and other equines. The same can almost be said for Savannah the elephant, who nurses her calves like a mother dog or cat (her teats would be on the chest, not the stomach).
** Leo and Savannah's MixAndMatchCritter babies. That is all.

[[folder:Films -- Live-Action]]
* In ''Film/AfterEarth'', humanity's former homeworld Earth is depicted as having changed dramatically in the thousand years since humans left the planet. Since then, the planet's rainforests have overgrown the continents, the weather changes from warm to ice cold every night, and "everything on this planet has evolved to kill humans". However, evolution does not work ''that'' fast. Biological changes on the scale depicted take millions, not thousands of years, and most plants and animals would have gone extinct trying to adapt to temperatures that fall far below freezing each night. In the time it would take for animals to change that much, humans would have changed significantly as well. Also, there'd be no reason for the animals to continue evolving abilities to efficiently kill humans since humans don't even live on Earth anymore. The primary predator of the film, the Ursa, is a blind creature that hunts by smelling the pheromones produced by fear. This is not a great feature for a predator; most predators hunt by ambush, since prey goes down faster if it doesn't know you're there. But if the prey is displaying fear, it likely knows the predator is there and so has a chance to run or fight back, which would only make things more difficult for a fear-smelling hunter.
* ''Film/AlienResurrection'':
** The plot hinges on [[CloningBlues creating a clone]] from blood samples to harvest the completely separate lifeform hiding out in the original Ripley's chest. Furthermore, red blood cells don't even contain DNA (though, white blood cells do contain DNA, so that might explain it).
** Supposedly Aliens bond with their hosts at the genetic level, hence all the weird superpowers Ripley got from the genetic mutations caused by the Alien (like the corrosive blood). That doesn't make very much more sense, but hey, it's ''Franchise/{{Alien}}''.
* In another '50s B-movie, ''Film/TheAlligatorPeople'', a physician uses hydrocortisone injections to induce accident victims to regenerate damaged body parts. While cortisones do reduce inflammation (swelling), and can therefore make injuries ''feel'' better, they actually ''slow down'' the healing process.
* '50s B-movie ''Film/TheAmazingColossalMan'' has one of the doctors tending to the eponymous rapidly-growing man describe the human heart as "one big cell." As [[Series/MysteryScienceTheater3000 Tom Servo]] says, "You're not a ''real'' doctor, are you?"
* Oh so very much in the killer snake movie ''Film/{{Anaconda}}'', all in the name of the RuleOfScary. Among other things:
** Anacondas don't grow that damn big. The size thing is actually addressed in a sequel. The protagonists go looking for a life-prolonging flower. Its said that Anacondas keep growing until they die, and then they discover that the flower is an essential part of the snake's food chain so it is living longer than it should so its growth never stops, thus giant snake. While there have been claims of anacondas growing to lengths of 40 to 50 feet (some cases such as that of Percy Fawcett report lengths of up to 62 feet) going back to colonial times, these claims are unreliable and probably exaggerated.
** They don't move at the speed of a cheetah in a chase. They can ''strike'' that fast, but not chase things that fast, even in water.
** They don't predominantly prey on humans (though it has happened), especially after [[SuperPersistentPredator encountering life-threatening resistance each time]].
** They don't eat multiple prey the size of a human being one after the other. After consuming a meal like that (which can take hours), the snake will find a secure location where it will remain immobile for months to digest its food.
** And they certainly don't regurgitate their prey just so they can hunt again out of sheer sadism. They sometimes do this for safety purposes, such as when they're threatened by a predator and they can't afford to be lethargic by having such a big meal in their stomach, or if they find their meal is too big to eat.
* Despite some scientists trying to handwave things in ''Film/{{Arachnophobia}}'', no species of giant spider could possibly exist in the real world.
** While there really are [[https://en.wikipedia.org/wiki/Social_spider species of spiders that live in colonies]], none of these are male-dominated colonies, nor do they have a singular "queen" like ants or bees.
** Arachnids and other insects breathe through their skin, and there simply isn't enough oxygen in the modern world's atmosphere for them to get any bigger.
** Scientists use a paralyzing agent to make spiders fall out of a tree in the film. Despite falling more than a hundred feet, the spiders survive. In the real world, that fall would have killed each and every spider; their bodies simply could not handle that much force.
%%* Creator/JamesCameron's ''Film/{{Avatar}}'' has some TaxonomicTermConfusion.
* Mice live a very short life -- 3 years at the most, but in ''Film/Cinderella2015'' Gus Gus and Jacqueline are shown to have long enough lifespans to witness Cinderella growing up from a little girl to a young woman.
* In ''The Cleaver Family Reunion'', [[spoiler:Grandma Cleaver]] reveals that she's been white all of these years, but has been taking melatonin to make her look black. Melatonin doesn't work that way... The correct term is "melanin". Melanin is what causes pigmentation of skin. Melatonin is a natural sleep aid.
* ''Film/{{Doom}}'' has the mutant monsters come from the genetic experimentation of long dead human Martian {{Precursors}}. Fair enough. But it turns out that the mutations are caused by there being a "[[InTheBlood gene for evil]]" in the "poorly understood 10% of the human genome" which the [[GeneticEngineeringIsTheNewNuke genetically engineered]] chromosome reacts to. Now, when one of these mutants bites a healthy human, it infects them like a ''virus''.
* ''Film/{{Elysium}}'': After his accident, Max says that he has so much radiation in his body that he is probably irradiating people in close proximity. Carlyle makes a similar claim when he worries about having to replace the sheets in the factory medbay, due to Max's skin falling off (which doesn't happen from radiation poisoning, neither in reality nor in the movie itself). Both are wrong because radiation can only be emitted by radioactive material; human tissue does not qualify. There's excuses for both, though; Max was trying to intimidate someone and may not even know better, and Carlyle is just a jackass.
* In a ''Film/FinalDestination'' movie, a girl is slowly pulled into the machinery of an escalator. As soon as her feet get crushed, she starts spewing blood all over her boyfriend. No reason for that, really. No digestive or respiratory organs in the feet. However, it is possible that getting her legs crushed between those cogs and gears caused her blood pressure to skyrocket, which would pop blood vessels (starting with the very weak ones, such as the capillary bed in the lungs). Imagine rolling a tube of toothpaste starting from the bottom up.
* In ''Film/TheFifthElement'', the head scientist, while referring to the still-a-sample Leeloo, says "I can't wait to meet him.", even though he has complete access to her DNA, so he ''really'' should be able to notice the lack of a Y chromosome. So he either a) misled the general for no good reason, b) gave Leeloo a GenderBender for no good reason, or c) he's incredibly incompetent and has this job.
* A Creator/{{Syfy}} remake of ''Film/TheFly'' has a man crushed in an open-shafted elevator (literally, the elevator "shaft" is a chain fence with no gate), it causes his eyes to bulge out while his face turns red, until his head pops and deflates like a whoopie cushion. Where is his skull? Never mind the weight of an open-air elevator being lowered that slowly wouldn't be enough to cause that much damage, most likely just pressing the lungs until he asphyxiated.
* ''Franchise/{{Godzilla}}'': Along with the breaking of the SquareCubeLaw preventing a monster that looks like Godzilla from reaching that size, various movies have additional examples:
** [[Film/{{Godzilla 1998}}
*** Godzilla runs at a rather high speed, at one point chasing down an attack helicopter. Coinciding with the SquareCubeLaw, large real-world creatures a fraction of Godzilla's size would splatter if they ever tripped moving that fast. And this ignores the physics of getting a creature with that much mass moving at that speed using anything close to real-world biology.
** The reason why [[HollywoodTactics infrared guided anti-aircraft Sidewinder missiles]] [[JustPlaneWrong fired from AH-64 Apaches]] failed to lock on Godzilla is because it's [[LiteralMetaphor "cold blooded"]]. Cold-blooded creatures don't literally have cold blood. They lacks built-in mechanisms of keeping their body temperature at a constant level, independent from the environment.
* In the Film/JamesBond film ''Film/{{Goldfinger}}'': A Bond girl is asphyxiated by covering her entire body with gold paint. Bond explains that people need at least a small patch of bare skin at the base of the spine for their skin to "breathe." This isn't true. At the time the novel was written, "skin asphyxiation" was taken seriously, at least by the public. The studio had a team of doctors on hand while shooting the death scene, and left actress Creator/ShirleyEaton's stomach unpainted to make sure she could breathe. In reality, death could result from heat exhaustion if the paint interfered with perspiration, or exposure to toxins if the paint were unsafe, but it would take a very long time.
* A woman is cut in half at the waist in ''Hillside Cannibals''; her intestines spill out of her lower half.
* In ''Film/TheHorrorOfPartyBeach'', a doctor explains that the monster is actually a dead human whose organs were invaded by aquatic plants before they had the chance to decompose, and calls the result "a giant protozoa." Protozoa are single-celled lifeforms, and "protozoan" is the word for describing one in the singular. Also, algae are not "aquatic plants". They're algae. But they're often referred to as aquatic plants, so that one gets a pass as "[[LiesToChildren one character simplifying the truth to explain it more easily]]".
* ''Film/IndependenceDayResurgence'' sees Brakish Okun waking up from a 20-year coma and is able to walk around and talk as if he had just woken up from a nap. After being asleep for that long, his muscles would be suffering from muscle atrophy and would barely be able to talk.
* ''Island City'' a 1994 made-for-TV movie, had the few remaining regular humans living in a small enclave surrounded by animalistic mutants. The mutants were called 'recessives' because the trait was inherited that way. One of the characters was -- get this -- HALF RECESSIVE, with all the increased strength and toughness but without the bestial aggression and reduced intelligence. Also, the inhabitants of the city wore colored crystals making their genetic status clear, to prevent the wrong kind of couple forming and producing the wrong kind of offspring. That would be fine, except there were THREE colors (should only be 2, carrier or not) and people were forbidden from mating with anyone whose crystal was a DIFFERENT color (should be, 2 carriers may not mate).
* ''Film/{{Jaws}}'':
** This film and its sequels are infamous for depicting sharks as relentless man-eaters. Great white sharks do not see humans as food due to lack of enough fat to provide them calories and usually (''usually'', not always) attack if provoked, smelled blood, or in a case of mistaken identity. They also need much of their energy to maintain their body temperature. Being opportunists, they will eat most things they can catch, but they don't specifically target people. Also, according to scientists in the 2000s, another reason sharks don't attack people is sharks apparently don't like the taste of human meat. After all, humans don't live in the ocean.
** ''Film/Jaws2'' has an orca that is mauled to death by the great white shark, and the supposed marine biologist claims that there are far greater marine predators than it, referencing the shark. In real life, orcas are capable of killing great white sharks and the only predator (besides humans and other great whites) that preys on great whites. There have even been cases of entire populations of great whites fleeing from an area due to orcas preying on one individual. Even a fully-grown shark would not bother attacking an orca as it is still less than half the size of the mammal.
** ''Film/JawsTheRevenge'' has the shark roaring, which sharks are incapable of due to lacking vocal chords (or ''lungs'', for that matter).
* ''Franchise/JurassicPark'' contains a few:
** One character who is supposed to be a [[ArtisticLicensePaleontology paleontologist]] saying "Dinosaurs and man. Two species separated by sixty-five million years." The problem being that dinosaur is not a species designation, but a much higher taxonomic rank. There are currently known to have been more than 1,000 species of dinosaur. Furthermore, most of these species have been extinct far longer than 65 million years (and most paleontologists would argue that some dinosaurs live to this day -- these dinosaurs are technically known as "birds"). It's almost like Dr. Grant knew he had to say something [[NoFourthWall for the movie trailer]].
** Another scene has him holding a baby dinosaur in his hands. "What species is it?" he hisses to a nearby geneticist. "It's a ''Velociraptor''," responds the geneticist. Neither of these trained scientists who really ought to know these things picked up on the fact that ''Velociraptor'' is the genus name. This is averted in the book, where the baby is identified as ''Velociraptor mongoliensis''.
** An early scene has the paleontologists digging up a ''Velociraptor mongoliensis'' in the Montana badlands. As the name implies, they lived in Mongolia, and not Montana. The misidentification of ''Velociraptor'' was actually due to ScienceMarchesOn -- the original book based its research on a (now debunked) palaeontologist who argued that ''Deinonychus antirrhopus'' was in fact a species of ''Velociraptor'', which means what they were digging for in the novel (which the film did not correct) was a north-American ''Velociraptor antirrhopus''. Every instance where the book and the film uses ''Velociraptor'' is therefore in actuality a reference to ''Deinonychus antirrhopus''. This does not take into account the lack of feathers and an egregious misunderstanding of ''Deinonychus'' anatomy, but this could be explained away (at least in the book) by the knowledge that these ''aren't'' "real" dinosaurs but a facsimile created by geneticists working with patchwork DNA and a flawed understanding of the beings they're trying to re-create. The cheetah speed (the actual speed was closer to that of a wolf, or only about half this) and chimpanzee intelligence (they were very smart, but not ''that'' smart) can at least be filed under [[RuleOfCool artistic license]].
** The premise of the movie (and the book). If the amber-preserved blood was any more than 1 million years old, the DNA would have been irrecoverably decomposed, no matter what it was preserved in. Cloning extinct species from before 1 million years ago is impossible. Also, if the DNA were available, we have absolutely no idea how to turn that DNA into a viable dinosaur egg. You'd need complete information about how the oviducts of that particular species operated even to get started, and we don't even have any fossils of dinosaur oviducts, let alone a clue as to their gestational duration, average internal temperature, etc.
** The Lysine plan. A plan to limit the growth of the dinosaurs by making them dependent on the amino acid Lysine, by taking away their ability to produce it themselves. Lysine is an essential amino acid. Most modern-day vertebrates (including crocodiles and sharks; superorders that existed in the Jurassic period) can't produce it either. And we make do without it, because we get Lysine from our gut flora or by eating things containing Lysine. The Lysine plan is a great way to limit growth of genetically modified bacteria, which depend on Lysine in the media if they can't make it themselves. For vertebrates, that obtain it from eating things anyway, it's not. The book at least acknowledges this as an in-universe whopper by [=InGen=]'s scientists, as it turns out it was no hindrance to the dinosaurs whatsoever.
* ''Film/LittleSweetheart'' almost avoids this, until the last few seconds. Elizabeth has taken a bullet to the arm, a bullet to the gut and then spent at least several minutes face-down in either the Pacific or the Gulf of Mexico. She's easily being moved by the ocean and she's not moving. A band-aid to the head is all you need!
* In ''Film/TheMatrix'', Agent Smith gives a [[BreakThemByTalking Breaking Speech]] on how humans are viruses, because they don't instinctively develop an equilibrium with their environment like other mammals and instead breed until they can't support themselves and have to move on. In reality, animals do not instinctively do that, and equilibrium is something forced on them (thus why animals that are introduced to a new area can be so destructive). Humans simply have the power to push past those opposing forces. On the other side, there are plenty of viruses that can inhabit a person but not kill them and form their own equilibrium, like many of those diseases that never really leave your system but also don't cause major symptoms.
* ''Film/MissionToMars'':
** One character arranges Skittles in the air in microgravity in the shape of about ten base pairs and declares it's the genome of his "perfect woman" (the human genome contains about 3.2 ''billion'' base pairs). Another character eats a couple; apparently it's now the genome of a frog. Easily written off as a joke, until later in the film: after seeing about five base pairs on a screen, a character declares that it "looks human". Five BP on their own would tell you nothing whatsoever about what you're looking at, not even which ''kingdom'' it belonged to, never mind species.
** The writers clearly lacked an understanding of genetics. To start with, one of the characters constructs a model of a DNA molecule from supplied spacial coordinates, then Jim is able to ''look'' at a (very small) string of computer-generated DNA, and see that it "looks human". This is impossible, because a) you can't tell what species a sequence came from by looking at such a small sample and b) spacial coordinates that form a double helix say precisely jack shit about what bases (and, by extension, what genes) are contained in the DNA sequence. Then someone mentions it's missing "the last pair of chromosomes," when the simulation makes it readily apparent it's missing the last pair of ''bases''. To top it all off, the coloring of the bases appear to suggest that a base pair is made up of two identical bases, which is just wrong.
* The Spleen from ''Film/MysteryMen'' is an in-character example, as he named himself for an organ that has nothing to do with his {{Fartillery}} superpower.
* A minor case in ''Film/MysteryTeam'', but it is somewhat unusual that Jason can bike several miles with one flat tire without showing any signs of fatigue.
* The African exhibit in ''Film/NightAtTheMuseum'' includes an ostrich, which is not a mammal. Error or not, this is [[http://www.amnh.org/exhibitions/permanent-exhibitions/mammal-halls/akeley-hall-of-african-mammals an actual part of the real museum exhibit]].
* The low-budget monster flick ''Octopus'' attributes its giant cephalopod's prodigious appetite for meat to a severe deficiency in iron, such that eating iron-rich flesh is all that's staving off its death from anemia. Mollusk blood uses ''copper'', not iron, as an oxygen-carrier, so if anything it should have been chewing on the imperiled submarine's electric wiring, not its crew.
* ''Film/Piranha3D'': The Piranha survived two million years in an enclosed cavern through cannibalism. Every predator gets about 10% of the energy his prey took in. So, every generation of piranha should have lost 10/11 of their population. Even assuming they magically preserved 90% of the energy, they wouldn't have made it that long without producers in their food chain! And just to add insult to injury at the end of the movie we find out [[spoiler:they've been fighting the babies, which are apparently as big as their full-grown prehistoric ancestors. So, apparently, this process made them bigger]].
* ''Film/{{Push}}'' has the lead character [[spoiler:inject soy sauce directly in to his blood stream with no side effect at all]].
* In the low-budget monster flick ''Razortooth'', the giant killer eel breathes air and slithers like a snake. It's also alleged to be incapable of metabolizing glucose "like a diabetic": a double error, as A) diabetics ''can'' metabolize glucose, they just don't do so at the right rate, and B) any animal with a nervous system that can't metabolize ''any'' glucose would be dead, as neurons quickly die from accumulated waste products if they have to subsist on fatty or amino acids instead.
* ''Film/TheReaping'': Members of the [[ReligionOfEvil Satanic cult]] sacrifice all their children to Satan, except for the firstborn, who are inducted into the cult, to ensure the cult itself can survive. In reality, you would need (on average) two offspring to survive (and reproduce) per couple just for the population to remain stable. Even if the cultists recruit outsiders to marry the kids they don't sacrifice, attrition would still wipe them out, as some of each generation are likely to die, fail to reproduce at all, or leave the cult.
* ''Film/ReignOfFire'': A whole species consisting of thousands of females and only one male? It's actually not impossible in real life: Blue-Headed Wrasses (a fish) have a reproductive pattern where they live in large schools of females led by a single male. When the male dies, one of the females actually switches sex and becomes the new male. In the film, though, killing the male results in the extinction of the species -- the biological version of NoPlansNoPrototypeNoBackup -- which is why it's listed here.
* In ''Film/ResidentEvil'', the Red Queen explains that zombification works by exploiting the cellular activity that continues after death, supporting the idea by stating that hair and nails continue to grow after death. [[http://www.snopes.com/science/nailgrow.asp No, they don't]], and considering the fallacy is spoken by a supercomputer that really should know better ''and'' is used as the main rationale for including zombies to begin with, this also makes it a CriticalResearchFailure.
* When Major Cain tries to persuade Alice to cooperate with Umbrella in ''Film/ResidentEvilApocalypse'', she calls herself a freak. Cain's reply? "No. You're not mutation, you're evolution!". If Alice were to breed and pass on her mutation, then it would be evolution.
* In the epic Creator/PatrickSwayze action film ''Film/RoadHouse'', there is a sex scene involving Swayze's character, Dalton, and his love interest (played by Kelly Lynch) that reveals that either Swayze's package is located somewhere in the vicinity of his belly button, or else [[BiggerIsBetterInBed Mr. Swayze is a very, very fortunate man]].
* In the Syfy movie ''Robocroc'', [=CGI=] sequences show how the film's nanite-infested crocodile has her physiology transformed, bit by bit, into that of MechanicalLifeforms. One of the first such scenes shows her red blood cells being converted by the nanites... ''biconcave'' red cells without nuclei, which are found in mammals but not reptiles. Presumably the writers figured audiences wouldn't recognize blood cells unless they looked like the sort humans have.
* ''Franchise/SherlockHolmes and the Curse of the Spider Woman'' Holmes meets Spiderologist #1 who recommends that Holmes visits Spiderologist #2. Meanwhile, criminal has murdered Spiderologist #2 and is impersonating him. Holmes spots the fraud because the criminal uses wrong terminology. Meanwhile Holmes, Spiderologist #1, Spiderologist #2 and Criminal '''all''' call spiders "insects".
* ''Film/SnakesOnAPlane'' plays fast and loose with biology, [[PlayedForLaughs mostly for laughs]].
** The snakes are shown as shockingly aggressive, actively pursuing prey, whereas most snakes (including those shown in the film) are relatively sedentary; the snakes in the film bite repeatedly for no apparent reason, simply killing without eating the people or defending themselves, and then move to attack and kill other people who are neither a threat nor viable prey. The snakes are described as being so aggressive and violent because they are being stimulated by sexual pheromones, except that snakes are not praying mantids or black widows and do not kill their mates while they have sex. If snakes ''were'' to be brought into a violent frenzy when in the presence of sexual pheromones they would require separate pheromones for each individual species, and would be just as likely to attack each other as humans, as any other species would be as much of a threat/competition as the people would.
** The Burmese python practically growls and flashes fang like an aggressive dog. Then it manages to kill the {{jerkass}} in moments, when in reality it would take much longer even if the guy had a heart attack almost immediately. Finally, the python has no problem getting human shoulders down its throat. A real python would need a few moments to unhinge and stretch out its jaw, and then would probably need some time to properly position a meal that wide. Assuming a snake that size (about 16 feet) could get its head over an adult male's shoulders in the first place; even most potentially man-eating snakes (over 20 feet) will have trouble consuming a large person and take hours to do so. Yes, there were time constraints, but still. At least the python seems to still have been working on its meal when the poor thing got sucked out the window.
* ''Film/StarshipTroopers''. The bugs are referred to both as "insects" and "arachnids" throughout the movie. Apart from those being mutually exclusive terms, it's unlikely that alien creatures from across the galaxy would belong to ''any'' terrestrial animal class. The film also ignores the square-cube law that would make those giant bugs collapse under their own weight.
* While ''Film/SuperSizeMe'' contains plenty of questionable science behind the "30 days of eating nothing but [=McDonald's=]" experiment, the one thing that's blatantly incorrect was the DVD extra where a [=McDonald's=] burger and fries were allowed to sit on a counter with food from other restaurants to see how long they took to decompose. The other sandwiches and fries showed signs of decay and mold before accidentally getting thrown out, while the food from [=McDonald's=] was virtually unchanged the entire time, with the implication that they're artificial to the core and pumped with preservatives. The ''real'' reason they didn't grow mold was because they were thin, greasy, and salty; what little water they contained evaporated quickly, leaving no suitable environment for mold to grow. It's the same reason fresh bread in a sealed bag will become moldy, while bread sitting on the counter will simply dry out and turn stale.
* In ''Film/TeenageMutantNinjaTurtles2014'', given, they ''are'' mutant turtles, however in the case of great blood loss as the turtles experience, giving them adrenaline would definitely give them short-lived pep but it would be short-lived and not last as long as through the end of the movie. The amount they received on their dangerously low blood pressure should also have given them heart failure within minutes.
* A scene in the bad Canadian vampire B-movie ''Thralls'' features the lead villain vampire ''punch another man through his stomach, tear part of his spine out and show it to him as the now-spineless man merely '''stands there'''''. And then, rather than break in half where his spine used to be... he just collapses.
* ''Film/TheWaterboy'': [[Creator/AdamSandler Bobby Boucher]] tackles his biology professor over the fact that alligators get ornery because of their enlarged medulla oblongata, leading to more aggressive emotions, instead of [[MyBelovedSmother Mama Boucher's]] explanation that "they got all them teeth and no toothbrush". They're both wrong, because the medulla oblongata has absolutely nothing to do with emotions, being responsible for breathing and heart rate. The amygdala is responsible for emotions.
* In ''Film/TheWorldIsNotEnough'', Renard has a bullet lodged in his medulla oblongata that is "slowly killing off his senses". NoOneCouldSurviveThat! This is credited with removing his sense of touch, despite this not being where the sense of touch is in the brain. The sense of touch is in the parietal lobe (mostly) which is at the top back of the brain. The medulla is at the bottom of the brain. While some have survived with bullets in their brains, such as Kiran Prajapati, who they were likely thinking of, if a bullet was damaging your medulla your heart would quickly fail, you would stop breathing, and your sense of touch would be fine. Until you die. Not to mention the absence of a sense of touch would produce a profound loss of balance. People who genuinely lose their sense of touch have to learn how to balance themselves all over again. And even then it's a tricky thing thereafter -- every time Bond hit him, he would lose his spatial awareness and have to reorient himself, or he would keel over.
* The ''Film/XMenFilmSeries'' has a whole collection of offenses.
** Mutants cannot be called another ''species'', given that they can still interbreed freely with normal humans. There is also the continuous reference to a so-called "mutant gene". In reality, any gene in the genome has the potential to be mutated. Even if you don't have a biology diploma, it ought to be obvious that there could be no universal "cure" that suppressed all the flashy mutations (but not "regular" ones like, say, heterochromia?) on any given mutant without affecting anything else, and certainly not in a matter of seconds.
** Invoked for the purpose of goading someone in ''Film/X2XMenUnited'', as when discussing the mutant gene, Pyro says that it is passed on by males. This implies that the gene is carried on the Y chromosome, which if it were true, would mean that there would be no female mutants. However, the scene makes it clear he just said this to get under Mr. Drake's skin.
** The iron injected into the prison guard wouldn't have gone unnoticed, least of all by the guard himself. Iron injections have a risk of anaphylactic shock -- high enough that many doctors won't prescribe them unless the patient has no other option -- and are incredibly painful.
** Not to mention the entire idea of a ''genetic mutation'' causing things such as ''the ability to control the weather''...
* Any Christmas movie which shows female reindeer without antlers, or male reindeer retaining their antlers into December. Females of the species need antlers to guard their young from predators, whereas males shed theirs after the rutting season, with one exception: gelded males retain antlers in winter. Also, most reindeer in fiction [[InformedSpecies do not resemble the real animals]], instead looking more like mule deer or white-tailed deer.
* A ridiculous number of movies, including the ''majority'' of vampire-hunt flicks, [[HeartInTheWrongPlace depict the human heart as being located near or slightly above the left nipple]]. The heart is located at the bottom ''center'' of the human ribcage, which means an awful lot of would-be Van Helsings actually gored their way into the target's left lung -- which, granted, is just as deadly to humans, though not vampires are supposedly killed only with the heart being stabbed. Also a RealLife misconception, given how people lay their hands over their left breast to salute the flag, pledge allegiance, etc. (mostly justified for women, though, as placing the hand directly over the heart usually means cupping their own breast). This specific manifestation is subverted in the Creator/GaryOldman [[http://www.imdb.com/title/tt0099242/ film]] ''Chattahoochee''. Oldman's character tries to commit SuicideByCop via a shooting spree, which doesn't work. He then takes his gun and shoots himself just above his left nipple. When he wakes up in the hospital, the doctor gives him a short anatomy lesson.

* ''Literature/{{Animorphs}}'':
** 'The Journey' -- Marco starts showing Rabies symptoms far faster than he should have; it takes weeks or months for that to occur.
** Also the fact his immune system didn't attack the whole gang right from the start.
*** The morphing process leaves traces of each absorbed animals DNA in the user, so it would necessitate some change to the immune system.
** In the first book, there's a mention made of Jake's knees reversing the first time he morphs into a dog. Dogs are digitigrade; presumably the author mistook the dog's ankles for his knees. This mistake allegedly prompted Applegate to start doing better research for the rest of the series.
*** Morphing doesn't always turn body parts into analogous parts. E.g. sometimes, morphing into a horse has each limb become a leg, and sometimes the front legs sprout out of the stomach.
* Early in ''Literature/ArtemisFowl'', Holly Short has a CharacterFilibuster denouncing sewage treatment as a [[GaiasLament horrible violation of Mother Earth]], inspiring FridgeHorror in readers familiar with modern Germ Theory. When [[CantArgueWithElves the elves are]] ''[[CantArgueWithElves this obviously wrong]]'', someone should definitely be [[ScrewYouElves arguing with them.]]
** Thankfully thee filibuster wasn't something the reader was supposed to agree with (because, as stated above, you shouldn't) but rather a demonstration of BlueAndOrangeMorality. The fact that elves think putting your restroom indoors is unhygienic was supposed to reinforce this.
* In ''Literature/ASeriesOfUnfortunateEvents'' the menacing pair of villains in the tenth book identify eagles as mammals. LampshadeHanging from the well-read protagonists.
* In Creator/MadeleineLEngle's ''Literature/ASwiftlyTiltingPlanet'', all of the good and significant descendants of Madoc, the good Welsh prince who sailed to America, went native, and married a Native American woman of a tribe called the Wind People, have deep blue eyes--regardless of their racial background. It doesn't matter if they are 99% Native American, they have deep blue eyes. The evil significant descendants of Madoc's power-hungry brother (who intermarried with the warlike People Across The Lake--enemies of the Wind People--and whose descendants intermarried with the native population of Vespugia) have either metal-gray eyes or ice-blue eyes. Because genetics color-codes eyes according to a person's morality. Uh-huh. The genes for blue eyes of all sorts are dominant, too.
* In the PointFantasy book ''Brog the Stoop'', it's mentioned that a female "Stoop" (vaguely elven creatures with blue skin) can only bear one "Stoopling," which would mean every generation is half the size of the previous one, thus leading to extinction pretty quickly.
* In ''Literature/TheCannibalsOfCandyland'', the Candy People apparently evolved through natural mutation their candy physiologies from their cannibalistic ancestors over the course of a few generations to better catch and capture their prey. The absurdity of such a fact is later [[LampshadeHanging pointed out]] by Franklin.
* ''Literature/TheChemicalGardenTrilogy'':
** Men outlive women, which is the reverse of what is biologically inclined to happen. This is especially egregious because the reason for the shortened lifespans is a virus -- women, having an extra X chromosome, would have more genetic material to copy from and would therefore be less vulnerable to a virus altering their genome.
** The book can't seem to decide if the cause for the DepopulationBomb is a virus or genetic engineering, which are two very different things.\\
Furthermore, the nice thing about genetic engineering is that it's almost always reversible, since there's always a copy of the original genome floating around somewhere. It would be easy for the geneticists to reverse the changes after people started dying.
* ''Literature/HereticsOfDune''. Highly oxygenated blood of a normal human is presented as being exceptionally black, while it should appear exceptionally red.
* Creator/WayneBarlowe does a pretty good job of maintaining consistent and possible alien biologies in ''Literature/{{Expedition}}''... except for the Daggerwrists. Pregnant Daggerwrists are cannibalistic and are executed by their tribes when their single offspring is born. If you can't do the math, this means that ''at least two Daggerwrists will die for every one born''.
** This could be an in-universe example as well, as the cannibalistic Daggerwrist may have been behaving abnormally, forcing its packmates to kill it and then salvage its offspring rather than wait for it to give birth. The researcher who observed this event came from [[EarthThatWas a failed ecosystem]] and had no experience with animals' natural behavior, so could've overlooked the incongruity.
* Likewise, the vampire-like creatures from Creator/GeorgeRRMartin's ''Literature/FevreDream'' seem doomed to slow extinction, as their females give birth to single offspring and always die as a result. Granted, Martin's vampires are actually ''aware'' of this quandary, but that can't explain why their young would evolve the self-destructive habit of clawing their way out of the womb, in the first place. At least the source is clear: that's what they thought about lions in ancient times -- hence the Aesop's fable about a hog boasting to a lioness about the number of her babies, to which the lioness replies "I have one, but it's a Lion".
* In the original ''Literature/{{Frankenstein}}'', Victor worries that if his monster had a female monster to mate with, they would produce monster babies. That would be fine and dandy if the monsters weren't made from reanimated human flesh, almost guaranteeing them both to be infertile. Even if by some miracle, they were able to conceive, any child of the two of them would in fact be human, biologically descended from whoever the monsters' reproductive organs came from.\\
Like the Sherlock Holmes example above, this is also actually a case of ScienceMarchesOn. The original novel was published twenty years before Schwann and Schielden founded cell theory, and almost fifty years before Pasteur definitively disproved abiogenesis. In fact, the most exciting discovery of the time was the effect of electrostimulation in disembodied muscle tissue, so the story of a creature made from dead human material reanimated by lightning was as grounded in modern science (in 1818) as literature about sentient computers is today. However, there is no reference to Victor using lightning; there is a single reference to the "apparatus of life"-the exact method is left unknown. The lightning comes from [[NewerThanTheyThink the 1931 film]].
** Every image of Frankenstein is from the movies. There is no tower, no lightning. He seems to have created the monster in his apartment and deliberately says he won't reveal his method because someone else might do it. Neither medium explains why he used body parts instead of just reanimating a single dead body that the parts must have come from. Also, he would have avoided using "Abby Normal's" brain. (The novel handwaves this by saying Frankenstein selected parts so his creation would be beautiful. Um, yeah.)
** The original novel does not suggest even that Victor made his Creature out of corpses, only that he studied the secrets of life and death by dissecting dead bodies. The novel's description of the Monster is almost a living sculpture, highly symmetrical and enormous in size, which doesn't indicate at least a direct human source in the raw material. Moreover, his abortive attempt to craft a bride for the creature takes place on a tiny, waterless island several days' sail from civilization: hardly a place where fresh corpses would be easily acquired.
* In ''Literature/{{Gone}}'', it is {{lampshade|Hanging}}d when Astrid points out that there is no gene for shooting lasers out of your hands. Justified, however, when it is revealed that the meteor that carried The Darkness seems to have broken reality.
* ''Literature/HarryPotter'':
** Creator/JKRowling, [[WordOfGod says that]] "[[http://www.mugglenet.com/editorials/editorials/edit-wilkins01.shtml magic is a dominant and resilient gene.]]" Given the number of wizards born to Muggle parents (and the extreme rarity of the reverse), this blatantly flies in the face of middle school genetics. You could say that AWizardDidIt (it ''is'' magic, after all), but a better explanation would perhaps be that magic is ''recessive'' and that squibs have mutations that block or repress the magic gene. This may be a whole class of subtrope: treating "dominant" and "recessive" as synonyms for "awesome" and "lame", rather than their proper meaning in genetics, which are "works even if you only get one" and "only works if you get two."[[note]]To be more precise, a dominant gene is one that tells a cell how to produce a protein. Even one dominant gene is enough to code. Two recessive genes means that there's no instructions, so a protein is not produced.[[/note]]
** Both [[Literature/HarryPotterAndThePhilosophersStone the book]] and [[Film/HarryPotter movie]] of ''Philosopher's Stone'' feature a snake that winks at Harry. ''Snakes can't wink'', owing to a lack of eyelids.
* Similar to several other examples on this very page regarding single offspring, there is a Dutch book by A.F.Th. van der Heijden called ''Het Leven uit Een Dag'' (Life In A Day). Humans only live one day in the book and can only have sex once, then their reproductive organs will wither away (the woman will get pregnant instantly). Since the humans in that world only get one child, each generation will be half the size of the previous one. Since a new generation only takes a day to grow up and die, humankind would be extinct pretty darn soon.
* ''Literature/HothouseFlowerAndTheNinePlantsOfDesire'':
** Orchidaceae are, in actuality, marginally more difficult to care for than graminoids.
** Berwin greatly miscalculates the value and rarity of certain plants. Oxalis, for instance, is a relatively common and inexpensive plant.
** Propagation is significantly more difficult in real life than it is in-universe.
* ''Literature/TheHungerGames'': In ''Mockingjay'', Katniss sees Peeta planting evening primrose and the only part she registers at first is rose. Fortunately the thorny roses Snow leaves and primrose are not even mildly similar to look at, so she realizes her mistake pretty quickly. Mistaking one for the other would be more or less impossible.
* Played straight and averted in Creator/ChristopherPaolini's ''Literature/InheritanceCycle''. At one point, the BigBad sends [[ImplacableMan soldiers who are immune to pain]]. This seems to endow the soldiers with cockroach-like resilience, with them surviving hideous trauma and being able to move despite cut tendons and broken limbs. One takes dozens of arrows and still has to be beheaded. In reality, the injuries would kill them despite an immunity to pain. Averted in ''Inheritance'', where the irradiated Vroengard is full of mutants, suggesting Hollywood nuclear physics, but it is in fact a magical effect. This might be a homage to the ''Discworld'' series, which also frequently draws parallels between magic and radiation.
* According to his backstory from ''Literature/JamesAndTheGiantPeach'', James Henry Trotter's parents were eaten alive by an [[RhinoRampage escaped zoo rhinoceros]]. In real life, rhinos are ''herbivores'' (they are the largest extant perissodactyls, i.e. related to horses). Fortunately, the film adaptation averted this by changing said rhino from an actual rhinoceros to a large rhinoceros-shaped demon made entirely out of thunderclouds.
* At what point did ''Lesbian Land 2250'' get an aspect of human biology correct? "Ginger Winters" thinks that vaginas are indestructible, all-encompassing, and incapable of infection, that breast milk can sustain a grown human. Under any normal biological conditions, entire chapters would culminate in much of the cast dehydrating and succumbing to desiccation. Also, the VoodooShark that comes up in the course of handwaving NoPeriodsPeriod, and the overall capacity it has to drive geneticists to alcoholism, and...
* ''Literature/MaximumRide'' often has shades of this, particularly by abusing the LegoGenetics trope. Splicing bird DNA into human DNA isn't exactly easy, and trying to engineer a WingedHumanoid would be far more complicated than taking bird DNA for wings and putting them into a human zygote. There are no genes for bird wings that one can just take and put into another creature. It gets worse when the characters start developing superpowers, some of which were planned by the scientists and others of which mutated randomly. How would they even do that? There are also some little things, like hawks nesting in large groups and large sharks in less than 5 foot deep water, but the genetics is the big one.
** This may be why in the Marvel Comics adaptation, the Flock are cyborgs rather than bird-human hybrids.
* In ''[[Literature/TheMillenniumTrilogy The Girl Who Played With Fire]]'', Ronald Niedermann is a 6'6" musclebound blonde giant, who has a disease which renders him unable to feel pain. The book even mentions that most people who have this disease die at a young age, but then hand waves it away by implying he's just too tough to die. This is not how it works. Normal life is dangerous enough for people with this affliction, but this character was an amateur boxer and gets in several fistfights over the course of the book. One untreated injury could conceivably kill him, most notably when he takes a full-strength punch to the kidneys from a pro boxer. But even before that, the kind of muscular frame he has cannot be maintained without weight training, which would be catastrophic without pain sensors to determine one's limits.
* The Douglas Preston/Lincoln Child novel ''Mount Dragon'' has a transgenic strain of influenza virus called "X-FLU." It was designed to be a relatively harmless strain of flu that makes anyone infected immune to ''all'' forms of flu. Problem is, it kills everyone because [[spoiler:the revolutionary new method used to purify it damages the capsid.]] This should only affect the first generation of the virus, which certainly shouldn't cause lethal brain swelling on its own. All progeny virions would be produced from the viral RNA [[spoiler:and left unpurified]], making them more or less what they were designed to be.
* In ''Literature/PrinceCaspian'', Reepicheep the talking mouse has lost his tail in battle, and he argues with Aslan over whether it needs to be regrown. Both of them seem to think a mouse's tail has no practical value, and is of use only as a badge of honor or vanity, but the tails of mice and rats are actually important thermoregulatory structures, without which he'd be quite vulnerable to heat stroke. (This is touched on in the movie adaptation: "Well, it's not just the honor. It's also good for balance, and climbing...")
* In [[Literature/{{Rama}} Gardens of Rama]] the refugees from the New Eden colony find another alien colony raising fields of corn, fruit and vegetables in the total dark of Rama... by having giant fireflies fly over and illuminate them. Clark may be an astronomer to the bone, but even elementary physics would tell him the energy economy can't work.
* ''Mariel of Redwall'', of the ''Literature/{{Redwall}}'' series, mentions Gabool the Wild having gold replacements for his canine teeth. Sadly, he is a rat, and rats do not have canine teeth to begin with. Judging by the illustrations of Gabool, the author may have meant his incisors.
* ''[[Literature/WingsOfFire Moon Rising]]'' has an in-universe example. The dragonet Winter is perplexed by his pet's refusal to eat meat, saying that if he's hungry enough, he should eat anything. He doesn't realize that some animals cannot digest meat at all.
* The first ''Literature/ThePaperMagician'' book depicts a valve between the second and third chambers of the heart, similar to the valves between the first and second chambers and the third and fourth chambers. This is not how human hearts work. The heart is divided into two parallel halves; the right half receives deoxygenated blood from the body and pumps it out to the lungs to pick up more oxygen, while the left half receives the reoxygenated blood from the lungs and pumps it out to the rest of the body. If you can get from one side of the heart to the other without actually ''leaving'' the heart, '''something is wrong'''. And this is after a character in the book has spent time ''specifically studying'' anatomical diagrams of the heart, [[spoiler: and has ''crafted a working prosthetic heart based on that knowledge'']], which gives the impression that the character has done more research than the author who wrote her.
* In the ''Literature/{{Replica}}'' series of YA novels, the bad guys repeatedly try to get hold of Amy's super-DNA by ''cutting her hair and fingernails''. The installment where her DNA reverted to "normal" after getting her ears pierced... wait, what?
* For Creator/ArthurConanDoyle, at the time the ''Literature/SherlockHolmes'' stories were written, legitimate scientists were speculating that some things might be theoretically possible, so it's more of a case of ScienceMarchesOn. That said:
** In "The Creeping Man", the eponymous character "devolves" into an ape by shooting up with monkey blood, or brain juice, or something. Just... no (an episode of ''Mystery'' based on this story had to put a disclaimer at the beginning of it explaining this fact, lest the audience treat the story's events as pure {{narm}}. It is instead claimed that the character has been driven mad by the adverse effects of the hormones so that he ''thinks'' he is a monkey).
** In "The Speckled Band", the villain controls a snake by whistling, which a snake would be unable to hear. This one was {{lampshade|Hanging}}d in a Russian miniseries. Watson points out that the snake couldn't possibly hear its master's call. Holmes replies that the villain wasn't sure in his method either, and so also tapped his cane on the floor.
*** The man also tempts the snake with milk (a common misconception). Holmes calls it "a swamp adder, the deadliest snake in India", a name which does not correspond to any species with the snake's characteristics.
*** In the same story, a man who collects Indian wildlife is said to have a pet cheetah and pet baboon. While cheetahs hadn't yet been driven to extinction in India in Doyle's day, baboons come from Africa: large ground-dwelling monkeys from the Indian subcontinent are properly called "macaques".
* ''Literature/SpeakerForTheDead'': Microbiology and crop cultivation are two overlapping fields but have ''vastly'' different implications. Justified by Xenobiologists being extreme OmnidisciplinaryScientist types.
* Creator/MichaelCrichton's novel ''Literature/{{Sphere}}'' has quite a few. The squid might get a pass for being an alien manifestation, although the biologist should know better than to believe that a normal squid could tear a metal structure to pieces. More flagrantly and not given a pass by the RuleOfCool, same biologist sees a seasnake and finds it perfectly normal to see one 1,000 ft down in near total darkness, AND makes a completely ludicrous evolutionary argument that marine organisms have more potent venoms because it's had longer to evolve (implying that land life arose separately rather than as an extension of marine life?). The whole discussion can be eliminated from the book with no negative impact yet it stands as a short AuthorTract.
* ''Literature/TheStand'':
** The explanations given for the operation of the superflu virus are sketchy at best, and it seems highly unlikely that the disease would have resulted in such massive destruction. (Among other things, a plague is deadliest if it has a ''long'' incubation period, giving it maximum lead time in which to spread before the victim becomes too sick to move around.) Still, there aren't any obvious screw ups... until the end. [[spoiler: Up until this point, the superflu had been a binary proposition: Either you got it and died, or you didn't get it. At the end, however, a baby born to one immune and one non-immune parent gets the superflu and then recovers; which leads the thoughtful reader to ask, what happened to the children of immune and non-immune parents born before the flu? As a bonus, the explanation given for how the baby recovered is a load of crap]].
** The explanation for why [[spoiler: the baby recovers and the children of immunes and non-immunes don't before the plague seems implicitly to be that the babies not born until after the plague have acquired protection from the plague by being in their immune mothers' uteruses at the time of the plague; those born before the plague are no longer connected to the mother and thus don't have the ability to catch it and recover]].
** In ''Literature/SalemsLot'' Dr. Cody, who is not depicted as an ignorant quack but an at least semi-competent professional, says, "Why should your head hurt? Your brain doesn't have any nerves." First off, if your brain had no nerves then it would functionally be useless. He means that your brain doesn't have ''nociceptors'', which is true, but doctors universally knew very long before the book was written that there are all sorts of reasons why your head still hurts. For example, while the gray matter ''itself'' doesn't feel pain the blood vessels that run through the brain do. Ice cream headache is one example of this type: the sudden rush of cold to the head makes the vessels temporarily painfully retract. Also, sinuses can cause headaches, as can the inner scalp. Very often it's the back of the eyes (which are less round and go further back into the skull than they look from the outside) hurting due to eye strain or what not. The skull can feel pain too, but probably only if you've suffered serious cranial damage. No one with an M.D. wouldn't know all this.
* In the ''Literature/StarTrekNewFrontier'' book ''Stone and Anvil'', it is explained that Mark [=McHenry=] gets his abilities because he is descended from Apollo and Carolyn Palamas. No one else in the line has these abilities because the godhead is carried on the Y chromosome, and all their descendants prior to Mark are female. Females have only X chromosomes, and there's no explanation where Apollo's Y chromosome was hiding out for the intervening century.
** A more likely reason would be if it was carried on the X chromosome and recessive, with no matching section on the Y chromosome. This would make it work like a form of Green/Red colour blindness in real-life humans.
* ''Literature/SurvivorDogs'':
** Realistically, a lot of the dogs would have a tougher time surviving than the wild than depicted. Sweet, for example, is a Greyhound. Due to their low body fat, they're known for getting injured very easily and getting cold very easily. Sweet still fares perfectly well in the cold environment and [[spoiler:is powerful enough to become an Alpha]].
** Dogs are depicted as monogamous, unlike real dogs.
** Dogs follow the outdated pack hierarchy system. Alphas are the leaders, betas are the second-in command, omegas are the lowest of the caste, everything is decided with fighting, etc. This system has is considered inaccurate to how wolf packs actually work.
** The dogs do not like scavenging on waste left by longlegs, finding it [[ScavengersAreScum demeaning]] and unsuitable for wild dogs. However, real feral dogs ''do'' scavenge a lot.
** The characters form packs like wolves. Studies have shown that domestic dogs don't do this. They scavenge (or hunt) smaller prey either individually or in parallel from one another.
* Medb, Queen of Connacht, from ''Literature/TainBoCuailnge'', is defeated because her period saps the strength of her army. The biology artistic license comes about because her period makes her ''piss'' blood. Enough to flood three parade grounds in fact.
* One of the books in the ''ThroughWolfsEyes'' series by Jane Lindskold featured conjoined fraternal twins, a boy and girl who had been attached at the hand. This is completely impossible any way you look at it, as conjoined twins are the result of identical twins whose egg failed to split properly; fraternal twins, who are conceived from two different eggs, cold never end up attached to each other.
* ''Literature/{{Twilight}}'':
** Vampires are stated to freak out when they smell human blood. When Bella gets a freaking ''papercut'', it's like throwing a hunk of meat into a shark tank. So, why don't vampires freak out when a girl is menstruating? It's dead blood.
** Considering the fact that sexual desire requires blood flow, there's no way vampires could have sex or sexual desire the way it's portrayed many times in the novels. Meyer says that venom serves the function of blood, but without a heartbeat? Not so much.
** ''Breaking Dawn'':
*** Vampires don't have any blood in their tissues, so Edward shouldn't be able to get an erection in the first place. Also, Meyer has said that Vampires' cells don't divide, but sperm is created by a type of mitosis called meiosis, which means that Vampire men shouldn't be able to get women pregnant repeatedly a la Nahuel's father.
*** Meyer stated that the reason female vampires can't get pregnant is because when you become a vampire your body can't change. That goes for male and female... so how do they have sex? Male and females reproductive organs have to be able to 'change' in order to have sex and I doubt every single vampire was turned when they were having sex or aroused.
*** Ironically this ought to be FridgeLogic that vampires [[TheyWastedAPerfectlyGoodPlot never actually have sex and only use the pretense of it to lure in their human prey]], seeing as how sex itself is obsolete to them as a species (they don't reproduce sexually after all) and they have no logical or biological reason to want to engage in the act.
*** Vampire venom at one point was stated to replace all fluids in the body which is why it turns into a sparkly rock like substance. If you follow that logic, his semen should have been replaced. So the first time they had sex and he orgasmed... she should have become a vampire instead of becoming pregnant.
*** Also, Vampires somehow gain two extra pairs of chromosomes after they change. Yeah.[[note]]They still can impregnate humans. And logically, gametes have 25 chromosomes, which with 23 of normal gamete makes 48. All human genes are in normal quantity and vampire genes seem to work in some range of quantity. One can infer that organism can function (better or worse) with zero, one or two copies of both vampire chromosomes, like with 1-n X, 0-n Y (all the X, XXX, XXXX, XXY, XYY... syndromes) or even 2-3 21 chromosomes (Down syndrome).[[/note]]
*** Werewolves also gain one extra pair of chromosomes. And Renesmee has one extra pair of chromosomes. Yeah, that she should have two unpaired chromosomes doesn't matter. In fact, all of ''Breaking Dawn'' has no clue at all when it comes to genetics.
*** The reason any species that engages in sex has a sexdrive is to ensure reproduction. Vampires don't reproduce through such means, thus sex is meaningless to them and they would have no sexdrive whatsoever. Which actually makes sense if combined with the bit about their bodies being unable to change -- they should neither be able to, nor want to, have sex.
** Smeyer has made it known that she is oblivious to how the eye functions, and how she lacks any knowledge of the color spectrum.
*** Bella sees rainbows around each source of light. We humans can experience the same using micro prism films, those glasses that make every light have a little image over them, or going around with the new 3D movie glasses. The only difference is that the glasses/prism film have a warning not to operate any machinery, drive, or go into direct sunlight wearing the glasses.
*** [[FridgeBrilliance That's why she's so clumsy?]]
* In one John M. Ford short story, a research lab comes up with a drug called [[foldercontrol]]

[[folder: Argent ]]
7 which gives the user superpowers. One user gives himself vision extending into the ultraviolet, by extending his retinas' sensitivity into that region. The problem with this is that human retinas are already naturally sensitive to UV -- what prevents us seeing in UV is that the cornea filters it out. (In RealLife, there have reportedly been experiments in which spy volunteers were given transplanted plastic corneas in order to be able to see into the ultraviolet.)
* ''Literature/WarriorCats'':
** Adult warriors can become FromStrayToPet if they wish to, though it's deeply looked down upon and they're seen as traitors to their Clan if they do. In real life, most feral cats (as in, they were born and raised on the streets with little-to-no human contact) cannot be homed after kittenhood. This is why, instead of trying to find them owners, Trap-and-Release programs release the cats after spaying and neutering them. Of course, real-life strays aren't sapient beings who rely on personal decisions and judgement over instinct, either.
** Neutered cats are portrayed as sluggish and fat. This is a reason why [[AnimalsFearNeutering cats fear humans]]. Learning about neutering helps persuade Rusty to run away to [=ThunderClan=]. This is an old myth. Cats, or dogs for that matter, don't become less active due to being spayed or neutered. Though given the feline characters are semi-anthropomorphised, one can assume their dislike of any other species that neuters them for convenience is valid. How would humans feel about another species who did that to them?
** Cats are portrayed as monogamous animals that mate for life. In real life, cats are anything but monogamous. As a result, Clans don't work like colonies. In colonies males will try to hoard females and females will usually try mate with any available male. Cats in ''Warriors'' go through courtships and stay faithful to one cat. (Although they also seem to consider questioning paternity to be rude, and apparently view adultery as less wrong than lying.)
** Cats are depicted as strictly diurnal. They rarely hunt at night and don't have very good eyesight at night either. While cats are not completely nocturnal, they are known to be active as night as long as they have some light, and have good low-light vision.
** ''Warriors'' is pretty bad with genetics and cat colours. A lot of characters have colourings that are {{implausible|HairColor}} or impossible for them considering their parentage.
** Cat pregnancies are depicted as longer than they actually are. Birthing is also portrayed as painful, difficult and as prone to complications as human childbirth, as well as very quick, with the kittens coming one right after another and the whole thing lasting less than an hour. In real life, cat births are much easier than human births, a trait common in all quadrupeds -- for obvious reasons, the less likely an animal is to die in childbirth or miscarry, the likelier it is that it will pass on its genes in surviving offspring. As such, natural selection has ensured that most mammals can give birth with ease -- human childbirth complications are mostly due to our fairly quick shift to full bipedalism causing some drastic rearrangements of our internal anatomy that we haven't had time to evolve past yet. Also, cat births tend to be fairly long -- the whole process usually takes up to twelve hours, with the mother having time to throughly clean and groom each kitten before the next is born.
** The average life expectancy for a feral cat is only around three to five years. While the series has a [[AnyoneCanDie very high death toll]], most cats live longer than that by several years. It's likely a pragmatic decision as it wouldn't be that interesting if cats died after only being a few dozen moons old.
** "She-cat" is not an actual term used when referring to cats. "Queen" or "molly" is more accurate."Queen" in the seris refers exclusively to nursing mothers, except in the first few books where it was occasionally used for any female.
** Hunting is much simpler in ''Warriors'' than it is in real life. While characters do sometimes fail to catch prey, most of the time they essentially just sniff around, see a vole or mouse, pounce, and catch it. In real life cats don't catch prey almost 100% of the time. They also don't always easily kill prey (hence why cats are known to "play" with their prey).
** [=LionClan=], [=TigerClan=], and [=LeopardClan=] are legendary Clans. The problem is that tigers and leopards are solitary animals, and it's unlikely they'd all interact anyway. It could be justified if the clans never existed and are just mythological.
** Kittypets are usually timid {{Non Action Guy}}s who rarely hunt or venture into the forest. Studies have shown that outside cats hunt ''a lot'' and they often walk long distances away from home while out
* In ''Literature/WorldWarZ'', the organ-smuggler claims that a transplanted heart from an infected donor would convey infection faster than an infected liver or kidney, because it has "direct access" to the cardiovascular system. While the heart does propel blood, it doesn't ''interact'' with the vast majority of blood that moves through its chambers; the liver and kidneys, which constantly add and remove substances from the bloodstream, would probably spread a viral infection much quicker than the largely-impermeable lining of the heart's chambers.

[[folder:Live-Action TV]]
* Dr. Holt (''Series/AGiftedMan'') had apparently never heard that you're not supposed to diagnose paternity based on ABO groups when he told an AB- man on the spot that his son, O+, wasn't his biological child. Although it is rare, the man could have been ''cis-AB'' and had an O child.
* In Season 5 of ''Series/{{Angel}}'' there is a scene in which someone looks into a microscope and tells Fred he can see that the disease-causing agent is a retrovirus. Not only would he be unable to see something this small without an electron microscope, but there is no easy way to tell by looking whether it is a retrovirus or not.
** Hypothetically, if examination of symptoms had narrowed down the potential diagnoses to ''either'' a known retrovirus or a known bacterial infection, then a differential white cell count could determine which of the two was involved. But that's not what happened in this example.
* ''Creator/AnimalPlanet'' really, really should know better...
** An episode of ''Creator/AnimalPlanet's: The Most Extreme'' was about modern day animals and their ancient ancestors. Fair enough...until they start talking about the Komodo Dragon and state that its ancestor was the ''TyrannosaurusRex''. If the producers of the show had done even five minutes of research on the Internet (or even just read a current book on dinosaurs), they would've realized that Komodo dragons and the Tyrannosaurus rex aren't even closely related to one another. A more true ancestor for the Komodo dragon would be the ancient Mosasaurs (sea-dwelling reptiles that lived around the same time as the dinosaurs). This is ArtisticLicensePaleontology -- your common farm chicken is more closely related to the T-rex (birds are essentially modern-day theropods) than the Komodo dragon is.
** As a lead-in to some trivia about prairie dogs, the narrator of ''50 Outrageous Animal Facts'' speaks of how mammals can sometimes be found in large groups. As he talks, shots of animal crowds appear on screen, including a beachful of walruses, a field full of wildebeest, and... a lake full of ''flamingos''. Large groups of '''mammals''', right...
* ''Series/{{Battlestar Galactica|2003}}''
** In season 2, episode 13, the supposed genius Dr. Baltar heals president Roslin's cancer by injecting her with some cylon/human hybrid blood that is more resistant to diseases because it has no antigens (which means it has bloodtype O) and therefore it has no blood type. Therefore it is somehow capable of destroying a cancer in a very late stage. Furthermore, cancer cells (or any other animal cell type) aren't cultivated in a petri dish and on agar, as it is shown on the pictures Dr. Baltar has, but are instead cultivated in cultivation flasks in a fluid.
* Sheldon in ''Series/TheBigBangTheory''. Yes, ''[[InsufferableGenius Sheldon]]''. When [[DrivesLikeCrazy he is unable to learn to drive on a driving simulation without]] crashing into a pet store or [[RefugeInAudacity ending up on the second floor of a building]], he claims that because he is the [[EvolutionaryLevels next stage in evolution of humanity]], citing his [[WeWillNotHaveAppendixesInTheFuture small incisors]] and his massive brain, he does not need to learn how to drive, because the task is beneath him. Evolution does not work that way! Sheldon Cooper is also egotistical and occasionally delusionally convinced of his own superiority. He has been known to occasionally ignore various scientific principles in order to win arguments, particularly when it comes to superhero physics.
** Given that humanity is still evolving, every generation is a new stage. Sheldon's only mistake is that he overexaggerates his own significance in the process.
** He is missing the point of natural selection. Because of his psychological quirks and self-centeredness, his "fitness" level currently appears to be very low (moreover he has a very low interest in finding a mate in the first place, much less conceiving and raising a child). Unless his attitude changes completely, he is going to be naturally selected against, and not pass on his genes. Evolution favors those who have multiple children.
** Though really, it was just an excuse for not being able to learn to drive, rather than him making a definitive statement about his evolutionary significance.
* ''Series/{{Bones}}''
** In the episode "The Dwarf in the Dirt," Dr. Brennan tells Sweets the chunk of brain Booth is missing would in no way mess with his aim because it was taken from his Frontal and Parietal lobes (which according to her only deal with memory). She then states that only the Occipital lobe (sight) and Cerebellum (coordinated movement) have anything to do with aiming a gun. The part of the Frontal lobe closest to the Parietal lobe is called the "Motor Cortex" and, oddly enough, is in charge of motor control. The Parietal lobe (which is a major part of spatial relations) has a part next to the Motor Cortex called the "Sensory Cortex" which, you guessed it, is about feeling ones body. Moving, feeling and spatial relations have nothing to do with aiming a gun... Nothing at all...
** The frontal and parietal lobes are the largest two lobes of the brain, so it depends on which parts were taken. But the motor cortex and sensory cortex are right beside each other, straddling the border between the lobes, so it's hard to imagine how a single piece could be removed that incorporates both lobes and ''not'' involve the motor and sensory cortices (in which case Booth would have troubles far more than just aiming a gun -- he'd be liable to be paralyzed on one side of his body in at least one limb). Also, the part of the brain most involved in memory is the Temporal lobe. And in a later episode they show an MRI scan of Booth's brain, and the missing part is most definitely not anywhere near the frontal or parietal lobes.
** In a minor example, one episode starts with a human falling to his death and landing in a field of cows. The witnessing cows just stand there placidly, and politely keep their distance from the investigators. Real cows tend to be curious, so would gather to see what was going on.
* ''Series/BuffyTheVampireSlayer'':
** "[[Recap/BuffyTheVampireSlayerS2E2SomeAssemblyRequired Some Assembly Required]]'' would have been a lot easier to swallow had there been a mention of the guys using magic to augment their biology work, but there wasn't anything said about it. First, it's highly unlikely that all three dead cheerleaders would have had the same blood type and been compatible enough for their parts to be grafted together. Second, there's no way any of their cells would have still been living by the time the bodies were recovered and used. (ditto with the dead football player who was brought back). Third, no one seems to recall that heads can't be transplanted without severing the spinal cord and resulting in complete paralysis. It's hard to imagine that's what the re-animated dead kid had in mind when he wanted a girl built for him.
** This trope is occasionally lampshaded in the scripts. A line in the script for "Some assembly required" written by Ty King describing a medical drawing reads, "it's of a woman's body, with muscles, joints, all kinds of equations and science type stuff (English major much?) scribbled all over it". Joss Whedon's script for "Graduation day, part one" has the stage directions "swabbing blood off the tip and putting it on a slide. That sounds real sciencey! Did I mention I was an English major?"
** Somewhat justified since Sunnydale sits on top of a Hellmouth, which constantly leaks magic (and attracts supernatural creatures) -- this probably allows a lot of people to do what they ''want'' to do, if they want it badly enough, even if normal biology wouldn't permit it.
* On one episode of ''Series/{{Charmed}}'' two characters performing an autopsy in the coroner's office both appear to believe that a woman with "high levels of testosterone" in her bloodstream is a biological anomaly, rather than a statistical outlier. "Testosterone? How's that even possible?" It's as if the writers believed that women normally have no testosterone in their bodies at all (in actuality, they do, and some have more of it than others).
* ''Series/{{Chuck}}'':
** An enemy agent injects herself with a sizable amount of ricin so that she will not talk. That's all well and good, as ricin has no antidote...but it also takes ''days'' to do its dirty work. She died instantly (cyanide is a better idea).
** On the third episode of Season 3, a foreign leader requires a blood transfusion and has AB- blood type. [[strike:Dr.]] Captain Awesome is trying to find someone with AB- blood type; even though people with AB bloodtype can receive A, B, AB, and O blood types as long as they are negative. AB- people can also receive red blood cells from all other blood types, however if it was a whole blood transplant, as would happen in an emergency, the sera (which contains antibodies) could cause major problems if not also from an AB- donor, as it would "attack" and cause an immune reaction against the recipient's own cells.
* In TheTag for an episode of ''Series/{{Community}}'' Abed, Troy and a character played by Creator/BettyWhite rap the biological classification of human beings with a remixed "Africa". While the song is an EarWorm there are two minor mistakes when the last 's' is dropped from Primates and Sapiens.
* In the ''Series/{{CSI}}'' episode "Crash and Burn," the suspect says, "I have to feed my fish. Clown loaches, tetras, angelfish..." when the aquarium clearly contains goldfish, angelfish, and a couple other species (possibly tetras in there somewhere). There are, however, no clown loaches -- probably because they're best kept in groups of 5 or more, in tanks over 100 gallons, which the tank in the episode definitely was not.
* On an episode of ''Series/{{CSINY}}'', a laboratory mouse is used to demonstrate how an apparently dead victim had been put into an experimental state of hibernation. The mouse is hooked up to a heart monitor, which can be heard slowing as it enters hibernation and then speeding up as it revives... but only to a (human) rate of ~75 beats per minute, rather than the ''500+'' beats per minute that would be typical for a mouse. A mouse with a human's heart rate would ''have'' to be in hibernation just to be alive.
* Something similar to ''Chuck'' occurs in the first season of ''Series/{{Dexter}}'', when Dexter has a flashback to being sick enough that he needed blood. He apparently has an extremely rare blood type that meant donor blood was in short supply, and they had to find a close biological relative of his to donate. That blood type? AB negative. While this ''is'' the rarest blood type, it's also compatible with any other type of blood, as long as that blood is also negative, to the point that AB people are referred to as "universal recipients". That said, there ''are'' extremely rare blood types... they're just not the ABO system types that everyone's heard of (in particular, there's an Oh type that's both very rare ''and'' which can't accept even the so-called "universal donor" O-type blood).
* ''Series/DoctorWho'' has many, many, many examples shown over the years. Some of these could be {{handwave}}d in one of three ways: 1) The TARDIS doesn't give a literal translation of the Doctor's biobabble, it instead renders something the companions can understand, even if it's wrong. 2) [[BizarreAlienBiology The Alien physiology]]/technology in question could work differently from our understanding. 3) [[RuleOfCool The Doctor makes it up cause it sounds cool]].
** The classic episode "[[Recap/DoctorWhoS15E2TheInvisibleEnemy The Invisible Enemy]]" beggars description. The BigBad is a prawn-shaped space virus which ''spawns''... let your imagination fill in the blanks.
** "[[Recap/DoctorWhoS28E1NewEarth New Earth]]" had the Doctor discovering an underground lair full of cloned humans infected with, in his words, ''"EVERY DISEASE IN THE UNIVERSE."'' They didn't die since all the diseases kept each other in equilibrium but if they touched ''you'', you died instantly and painfully. How did the Doctor cure these poor souls? Why, he doused himself in ten or so ''intravenous'' solutions designed to cure the diseases, then transmitted the cure by touch. One of these diseases, called "petrifold regression", [[TakenForGranite turns you into stone]].
** In "[[Recap/DoctorWhoS29E4DaleksInManhattan Daleks in Manhattan]]", the Daleks are using a giant lightning rod to power their genetic experiments. Okay. The Doctor mixes his own DNA into the results ''by hugging the lightning rod as it's struck by lighting''. Whu? DNA is conducted by electricity now?
** In "[[Recap/DoctorWhoS29E6TheLazarusExperiment The Lazarus Experiment]]", the weird scorpion monster that Professor Lazarus transforms into is said to be an evolutionary possibility that humanity rejected long ago but has remained locked in the genes, or something along those lines.
** "[[Recap/DoctorWhoS30E3PlanetOfTheOod Planet of the Ood]]" has Mr. Halpen constantly downing hair tonic which [[spoiler:turns out to be Ood-secretions that TURN HIM INTO AN OOD. Complete with the external forebrain, which can apparently break through the hard palate to come out his mouth]].
** In "[[Recap/DoctorWhoS31E8TheHungryEarth The Hungry Earth]]" while explaining that the [[spoiler:Silurians]] aren't aliens, he calls them 'Homo Reptilians', which implies that reptillian aliens are the same genus as mammalian humans, which is impossible in RealLife.
** In "[[Recap/DoctorWhoS34E5TimeHeist Time Heist]]", the Teller's ability to reduce its victims brains to soup somehow also caves in their skulls, the bone going from a nice convex dome to a concave section where the forehead and front half of the top should be. It makes the victims actually ''look'' like their heads are empty, and is all the more horrifying for it.
** "[[Recap/DoctorWhoS34E7KillTheMoon Kill The Moon]]" features [[MegaMicrobes giant single-celled prokaryotic spiders]]. Not only would this make eating and web production very difficult, not only is it [[SquareCubeLaw outright impossible]], but the Doctor apparently cannot pronounce "prokaryotic".
*** Throw in the spiders being instantly killed by a spray of disinfectant, the Moon being an egg that somehow gains mass, and the hatched Moonling instantly laying another moon-sized egg exactly where it was before, and the show hit a new low for biological (and scientific) plausibility
* ''Series/EleventhHour'' likes to screw up cloning (at least the clones ''are'' born as infants and not carbon-copy adults with complete memories). In the first episode, Jacob Hood insists that cloned pregnancies are more dangerous to the mother carrying the clone and that you need the "real scientist" at the birth, when in fact a cloned infant poses no more threat to the mother than an ''in vitro'' pregnancy, which is scarcely more risky than a natural one (and in fact the mother's health is only in jeopardy if her own body is incapable of carrying a pregnancy; if the baby is unhealthy it will simply miscarry). Then in a later episode, he makes the claim that clones are born genetically the same age as the original that they were copied from (so even though they look like babies, their genes are [[ReallySevenHundredYearsOld actually adult or even geriatric]]), stating that the telomeres which break off each time a cell replicates are severely shortened. However, scientific research measuring telomere lengths has proved this to be false; the developing embryo somehow "knows" how long its telomeres should be [[ShownTheirWork and resets them to this length with the enzyme telomerase]].
* ''Series/{{Friends}}'' : Rachel is pregnant for at least fifteen months, being already pregnant at Chandler and Monica's wedding (May 15th) and going on maternity leave in August the ''next'' year.
** Not to mention the episode with Emma's first birthday party airing in the fall.
** Despite many season premieres taking place within minutes or even seconds of the previous season finale, hair has somehow managed to grow several inches.
** That's why they don't film entire scenes before the season is over. That way, the audience has a summer to "forget" what the characters looked like and will accept the changes with little fuss.
** Ironically enough they also {{lampshade|Hanging}} plot devices like this through Joey's work on ''Days Of Our Lives'': his coma-bound character gets a brain transplant that turns him into the donor's character in a new body. Later, he somehow reverts back to his old character (Drake Ramoret) when his body ''rejects'' the brain.
* In an episode of ''Series/{{Fringe}}'', the MonsterOfTheWeek is a fast-moving, foot-long slug that turns out to be an engineered ''cold virus''. Walter attempts to {{Handwave}} this by stating that it isn't entirely unprecedented since large ostrich eggs are single cells. Except viruses aren't cells. Cold viruses are strands of genomic DNA contained inside of a protein coat, and entirely unable to move under their own power. Saying that it was a "giant" cold virus makes as much sense as a "giant" hemoglobin molecule.
* ''Series/GameOfThrones'':
** We're told that the Targaryens often married brother and sister to keep their bloodline pure over their 300 year reign, with an inference that they'd been doing it prior to Aegon's conquest, as well. In reality, severe mental and physical debilitation would result from this level of inbreeding (Charles II of Spain is a good historical example of the result). Instead, the Targaryens are physically flawless and only suffer from occasional instances of madness. It's implied that there's more than a little magic in their bloodline, which might be a mitigating factor.
** Hair color appears to be carried on the Y chromosome; if you know a man’s surname, you know his great-grandfather’s (and great-grandsons’) coloring. This also applies to a man’s daughters (Cersei Lannister, Daenerys Targaryen)--but ''their'' children will then have their fathers’ hair color.
** Without testicles secreting testosterone, the muscular development shown by some Unsullied borders on unnatural.
** The many foramina in the human skull would make it very impractical to use as a container for wine the way Karl does in "Oathkeeper".
* This is seen frequently in ''Series/{{Helix}}'', in spite of the attempt to ground {{Plague Zombie}}s in epidemiology, using fictional CDC employees.
** The CDC team accepts injected RFID chips from a shared device. This is risky, considering that this could be a method of transmission of TheVirus, and they don't know who are asymptomatic carriers, including the device's handler.
** Arctic Biosystems {{designer|Babies}} lab rats, who lack sex organs so they're more docile, are a solution in search of a problem, since lab rats are already docile, and removing sex organs removes both avenues of study (effects on reproduction, etc) and ability to compare or extrapolate from research on non-customized rats.
** Less than a day is insufficient time to determine, via rat observation, if TheVirus is airborne. Even if true this shouldn't be cause to remove a HazmatSuit, as it could be absorbed through the skin, and bodily fluids can aerosolize.
** Mutagens are, in and of themselves, not so disturbing to work with as Julia and Hatake say. They're used in cell biology.
** Alan is frightened that an infected Peter will be killed by halothane gas, and wants him alive because he may have developed antibodies which takes five days, while Peter's had TheVirus for three.
** Viruses are not typically searched for by shape, and when Julia says she's searched for all of them, "''even'' isocahedrons" she's treating the most common shape as though it were unexpected.
** The Zeiss phase-contrast microscopes depicted can't produce such animated images, much less show a virus that's smaller than usual. (viruses also don't move like protozoa). They'd need electron microscopes to see such small objects.
** In "Vector," Julia says rabies "doesn't include a compulsion to spread the disease" but that's ''exactly'' how rabies works. This error is odd since Peter's first symptoms are a supernatural exaggeration of rabies. His frightened refusal of water mirrors its hydrophobia, and the neck pulsations evoke the painful throat spasms that happen after those with rabies try drinking.
** Isolation and safety protocols are more talked about in the abstract then abided by. Isolation facilities should be larger and more secure given Arctic Biosystems extensive work with pathogens. In "Vector" Dr. Bryce is correct that he and Sulemani should be separated from the sicker Haven, since late stage infectees are super strong and violent. In "274" Daniel is likewise correct when he thinks now-symptomatic Sulemani and Bryce should stay isolated from the asymptomatic in quarantine, and Alan's failure to account for this violence results in Bryce and Sulemani's deaths.
** By the same token, the switch, over the course of three days, from HazmatSuit to face shield for interacting with infected is unwise, given that, in "274" its easy for a Vector to slip one off mid-assault, and one strain is known to be hemorrhagic and lethal. Even face shields aren't employed consistently.
** In "274" That the rapid response test wouldn't work is almost a ForegoneConclusion, given that Sarah sampled too few people to be assured of its efficacy, even given a limited population and time frame to work with.
* ''Series/{{House}}'': In one episode, the title character triumphantly demonstrates a tick that was causing the Case Of The Week; in a close-up, one can clearly see it has six legs, as every insect does... but ticks are arachnids, and, like spiders or scorpions, they have eight legs.
* ''Series/ICarly'':
** In-universe, with this exchange:
--->'''Spencer:''' Do girls ''have'' bladders?\\
'''Carly:''' "Do butts have muscles?"
** Maurice the Chicken. Called a male name. Makes rooster sounds. Is actually a hen, a female.
* On Creator/DiscoveryChannel's ''I Shouldn't Be Alive'', the narrator explains the effects of hypothermia on human cells, using the term "cell walls", in one episode (and is sure they have used it other times). Animals do not have cell walls (in fact, Animalia is the only kingdom where they are absent). Yes, they probably just don't want to explain what a cell membrane is/assume the audience won't understand the explanation, so they use a term the audience will know. Considering Discovery's association with fact and science, it seems like they would be willing to spend an extra ten seconds quickly explaining what it is.
* A Korean drama special entitled ''Last Flashman'' has a girl find out a shocking birth secret (that she's an alien or something) because she has blood type O but both her parents have type A. Most of the people are shocked and confused and maintain strongly that it's impossible to have blood type O from A parents. This is biologically wrong, since having O blood type with A parents are perfectly possible -- a person with A bloodtype can have the allele pattern Ai, and if each parent donates an i, the child gets an O. It would be odd if it was two [=ABs=] giving birth to an O, or two As giving birth to an AB, or two Bs giving birth to an A, or two Os giving birth to an AB or A or B, but this is not the case.
* ''Series/LifeAfterPeople'' just lapsed into this trope, showing footage of ''Volvox'' and ''Paramecium'' -- two well-known varieties of protist -- while discussing how living bacteria might've hitched a ride on one of NASA's deep space probes. Protists are more closely related to ''us'' than to bacteria, and the types shown would die just as quickly as we would in hard vacuum.
* Nobody expects a fake-cryptid-sightings show like ''Series/LostTapes'' to keep up scientific credibility, but the statements of their bogus "experts" can contain such idiocy it makes you wonder if they're doing it on purpose. When discussing werewolves, a fake biologist cites instances of a chameleon or octopus ''changing color'' as examples of "metamorphosis".
* ''Series/{{Monk}}'': A woman kills a billionaire by poisoning a death-row inmate, thus ruining the kidney he was going to donate to said billionaire. They both apparently have the "rarest blood type in the world" -- "AB Negative with D antigen." Except that the Rhesus D antigen is ''what we mean'' when we say "positive" or "negative." No wonder AB Negative with D Antigen is so rare... ''it doesn't exist!'' "AB with the D antigen" would mean he's AB+... and therefore can accept ''any blood type''! Also, only blood expresses the Rhesus antigen. All that's required to match in organ transplantation is the ABO blood type; all the recipient needed was another AB-type kidney.
* A suspect on ''Series/{{NCIS}}'' told Ziva that his aquarium held clownfish, triggers and lionfish. The fish in the tank are clearly clownfish, porcupinefish and surgeonfishes, and keeping lionfish in the same tank as smaller fishes is a great way to get the latter envenomated or swallowed.
* ''Series/{{Norsemen}}'' has a 780 AD slave state that urine is sterile, which is a common modern misconception. While urine is sterile in the body, the moment is passes out a urethra it stops being sterile. However, it's RuleOfFunny just for a Dark Ages slave to be aware of the concept of sterility to begin with.
* ''Series/TheOuterLimits1995'''s Season 7 "Flower Child" was a flagrant offender in this category, featuring Violet, a plant lifeform taking the form of a hot chick via stealing human DNA. At the end of the episode and when her plans are questioned, she reveals her plans for Earth -- to the human male who "fathered" her family of spores, no less -- with the words "A new species, part you but more of me. To spread across this land, to become many. To become dominant." Isn't the whole point of inherited genetic characteristics that each parent contributes HALF of their DNA to the child, and not more than half? But even more so, since Violet's human form isn't 100% E.T. by default, isn't the new species going to be more him?!?
* The creators of ''Series/{{Primeval}}'' do this knowingly and willingly for the sake of RuleOfCool.
** Most notably, the ''Dracorex'' looks less like an ornithischian dinosaur and more like a [[DinosaursAreDragons dragon]], with wing-like dorsal crests, exaggerated horns, and no cheeks.
** Also, while the time for tranquilizer darts to take effect varies, it's usually more than ten minutes, as opposed to less than five seconds.
** In the first episode, Cutter comes across a human skeleton. He is initially worried that it may be [[ChekhovMIA his missing wife]], but he soon realizes that it's a male skeleton and thus can't be her. Fair enough, but ''the way he checks'' is by ''[[LamarckWasRight counting the number of ribs]]''. Never mind that this is based solely on the [[Literature/TheBible Biblical account]], which even then only affected one individual from who knows how long ago (it was never said to be a ''hereditary'' trait). Checking the shape of the hipbones would be easier.
* ''Series/{{QI}}'' has an episode about animals and SeanLock, either as a joke he kept up all evening (claiming that he learned everything he knew about animals from glamour-model Katie Price), or through what he professed to be sincere ignorance, was unable to score a lot of points. Among other "facts", he claimed that Rhinos are dinosaurs, because he thought they were called "Rhinosaurus".
** In another episode, host Stephen Fry rather patronisingly "corrects" Jimmy Carr when the latter suggests that marsupials are mammals, which they are.
* On ''Rides'', the build team works to incorporate a real human skull into a spooky-themed vehicle's sound system. The narrator constantly refers to the skull as "he" and "Don", yet the ''numerous'' close-ups show features that suggest it's really a "Donna". Granted, the show's cast have no training to recognize this... but you'd think the suppliers who provided the skull would've mentioned it.
* In the third episode of ''Series/{{Sanctuary}}'', Zimmerman claims that the last major outbreak of the Bubonic Plague was in 800 AD (the end of the Plague of Justinian). Leaving aside for the moment that he should have said "[[UnitConfusion AD 800]]," the last major outbreak of the plague was in ''1945''. He was only off by about ''a millennium''. Even ignoring the occasional outbreak in modern times, he's completely missed a little thing called "The Black Death" in the 14th century, the most famous plague outbreak in history, where it killed one in four Europeans.
* In ''Series/TerminatorTheSarahConnorChronicles''’s first season, Derek needs a blood transfusion. Apparently, he needs his own blood type despite being AB ("Universal recipient", able to take blood from any other type)... Sarah said she was type O ("Universal donor", able to give blood to anyone), but her biological son John was AB?! Even if John's father Kyle was also AB, John must have an O from his mother, so he's either A or B, yet his not-AB-blood worked just fine...
* In one of the early episodes of ''Series/{{Smallville}}'' (which, admittedly, is not well-known for scientific accuracy), an embittered [[LonersAreFreaks loner entomologist]] decides to take out his [[WithGreatPowerComesGreatInsanity newfound mutant aggression]] on his mother. He blames this on his nifty bug genes, but rather than describing a real critter, he likens himself to the fictitious pharaoh spider. The fact that this creature exists in ''VideoGame/SphinxAndTheCursedMummy'' is either a coincidence or a ShoutOut, as the game wasn't released until ''two years'' later.
* The entire ''{{Franchise/StargateVerse}}'' series is filled with terrible biology.
** In ''Series/StargateSG1'' and ''Series/StargateAtlantis'' there are many references to humans not being as evolved as other alien races. Plus how you ascend, you have to evolve into it, or jump into an evolution machine, or have your brain operating at a certain "wavelength" or whatever happens to be the trope of the week.
** The Asgard have a serious problem -- they are all clones and because they simply clone their last body their DNA is degrading! It seems that nobody had the bright idea to not copy the last clone, but just use the original copy every time. Though this is actually the point -- they do not have any original from back in the time when they were still well enough. They found some ancient frozen Asgard, but those were not yet ready to be used as "hosts". There is no saying what the requirements of the clone are -- possibly, the mind transferring process isn't actually as simple as they make it to be -- possibly, the body has have some compatibility with the "transplantee". By the time they realized they have a problem, it was already too late. Yes, they could have bought some time if they stored some current copies for later use, but at the end of the series, [[spoiler:they made it clear they do not want to protract their "death" as a species any longer, when there are no advancements in their condition]].
** In ''Stargate Atlantis'' Dr. Becket concludes that the Wraith evolved from the Iratus Bug by using every trope in the biology book. The DNA of the Iratus Bug mixed with human DNA, and because parasites are normally identical to hosts they feed from, the Wraith were born.
* Too many ''Franchise/StarTrek'' episodes to name (some are covered on the subtrope pages).
** Another ''Enterprise'' offender: an Ensign has a slug-pet that is not faring well on board ship, so they drop it off on a planet. Not its native planet -- just ''a'' planet. Admittedly it won't have any breeding stock, but ''still''...
** ''[[Series/StarTrekVoyager Voyager]]''
*** In the episode "Macrocosm" we have viruses(!) which can grow in size -- up to a meter, fly, and hover in the air. It turns out that they somehow could do it by taking an alien growth ''hormone''.
*** The Occampans (Kes' race) in ''Voyager'', can only reproduce ''once'', and have ''one child''. What kind of species would evolve such a trait and thrive? You'd need EVERY member of your race to reproduce to have 0 population growth. If any member of the race dies, then the race as a whole has taken a blow it cannot recover from! ''How'' did the Occampan race come about? Since they can have only one child, and thus cannot grow in numbers, how are there so many of them? It was actually explained in a novella that twin and triplet births were extremely common among Ocampans, so it depends how you look at it. It still doesn't excuse the fact that they can only give birth while ''standing up,'' increasing the chance somebody is going to drop the baby upon delivery.\\\
The way Kes's species reproduces makes no real sense. The child can only be delivered standing up (the baby coming from the back), maximizing the chance of mortality from the baby falling to the ground, sex is a very complicated procedure which includes foot massaging, and they can only have ONE child in their ENTIRE lives. Even if both the men and the women of the species had babies with a 0% mortality rate (and none of those babies die between birth and having their own child) that means they can only maintain their current numbers.
*** Though there is some evidence that human birth is easier on the mother if done while standing up
*** Perhaps those are limitations caused by the dependence from the Caretaker.
*** In the second episode, Kes asked for soil samples to help her in setting up a hydroponics bay. Hydroponics is the means of growing plants ''without'' soil. Possibly excusable if the samples were being analyzed to determine the right proportions of minerals to add to the hydroponic fluid.
** The ''[[Series/StarTrekTheNextGeneration TNG]]'' episode "Genesis" was on a par with "Threshold" -- demonstrating that Brannon Braga may have a [=PhD=] in this trope. Switching on Barclay's T-cells causes the Enterprise crew to -- sigh -- devolve to a variety of different species... most of which have common ancestors diverging HUNDREDS OF MILLIONS OF YEARS AGO -- and Spot the cat becomes an iguana. Apparently in Star Trek, everyone walks around with copies of not only the future evolutionary patterns of their own species but ALSO whole swathes of species that are completely unrelated to them from their home planet. The worst offender being Barclay's devolution (and presumably re-evolution) into a ''spider'', which would only be possible if he devolved into a pre-Cambrian lifeform first.
*** Data devolving into a pocket calculator would have made more sense.
*** This was already plumbed with ''TNG'''s "The Chase", which attempts to cure at least three problems at once...by making all of the Alpha Quadrant's DNA part of a message by a progenitor race, also humanoid, that "seeded" planets with their genetic code in the hope of more sentient humanoids like themselves popping up. Cue Picard facepalm.
*** An original idea that inspired a lot of 'ancient ancestor' settings. The original humanoids found that their home galaxy (not just one quadrant) contained no life that was like them. Their own extinction fears drove them to seed the Milky Way and as a result encourage humanoid life to develop. The code was like a signature for them -- they wanted the Milky Way races to find out their origin to encourage cooperation.
*** Which, of course, implies that every ''non''-humanoid carbon-based life form in the ''Star Trek'' franchise, from the grape vines in the Picard family vineyards to Captain Archer's beagle, is essentially doing it wrong.
* ''Series/{{Supernatural}}'':
** One episode involved changelings that replaced children, then fed on the unsuspecting mothers' synovial fluid. The creatures left big lamprey-like bite marks at the bases of the mothers' necks, which only makes anatomical sense if they feed on ''cerebrospinal'' fluid; to get synovial fluid, they ought to have bitten knees, hips, and other large diarthrotic joints. A loss of synovial fluid should not cause death, by the way: it causes severe arthritis, which none of the afflicted mothers exhibited.
** In another episode, a charred bone from a witch's bundle is identified by the boys as that of a newborn baby. Long bones of infants don't have fused epiphyses on their ends, while this one clearly has them.
* Brannon Braga, of ''Franchise/StarTrek'' fame, went on to create a short-lived sci-fi series also called ''Series/{{Threshold}}''. The premise? [[AssimilationPlot Alien space signals]] cause people's DNA to begin re-writing itself! At least this time, the characters acknowledged that this should be impossible and had trouble dealing with the idea that it was actually happening.
* ''Series/TheTomorrowPeople''. What makes it worse in this case is the fact that the show had a scientific advisor listed in the credits!
** Claims that evolution takes "thousands" of years. It is far more complicated than that. Populations and species are constantly evolving -- they are not simply different a million years later. Microbes, bacteria and viruses especially, evolve in terms of decades and ''single years''. Why do you need a flu vaccine every year? Why do bacteria like MRSA come along? Microevolution.
** In "Hitler's Last Secret", John [[TechnoBabble explains, straight faced]], that "Genes are those body cells known as the DNA molecule." Which is like saying "voting districts are those sovereign nations known as the first-past-the-post electoral system"—each of the component phrases has a definite meaning, but they are combined into ''gibberish''.
* The spin-off ''Series/{{Torchwood}}'' has a character ask if Weevils might be mutating and thus becoming immune to the Weevil spray. So far so good. Then the BattleButler adds "or evolving".
* An episode of the Creator/NationalGeographicChannel's series ''World's Deadliest'' claimed that the lion is the largest African predator. A large Nile crocodile can weigh five times as much. Potentially due to confusion over "Carnivore" (as in "order Carnivora", of which the lion is indeed the largest member in Africa), and "carnivore" (as in "meat-eater in general"), which is often used interchangeably with "predator" (despite scavengers also eating meat).
* ''Series/TheXFiles'' has a bit of this with most monsters-of-the-week.
** Human-flatworm hybrids can happen on their own with enough [[NuclearNasty radioactive sludge]].\\\
The same monster also mashes together three different and entirely unrelated flatworms: [[http://en.wikipedia.org/wiki/Planarian planarian]] (the "larva" prop animal [[note]]In fairness, it must be quite hard to obtain large, living flukes for filming[[/note]]), [[http://en.wikipedia.org/wiki/Tapeworm tapeworm]] (it has a ''scolex'', i.e. the "head" of a tapeworm), and finally [[http://en.wikipedia.org/wiki/Trematoda fluke]] (the name given).
** In "Blood" an LSD-like substance was combining with adrenaline to produce a hallucinogenic substance... in the eyeball. They have visual hallucinations (or did they?) The eyeball could probably absorb it into the blood, but the coincidence is a bit much.
* ''{{Series/Catastrophe}}'': The sex of the baby can already be seen on the ultrasound, even though it's only been just over a month from the likely conception date (Rob is told by Sharon that she's pregnant thirty two days after, and goes immediately to London). Fetal genitalia don't even develop until around the ninth week, and can't usually be seen until twelve weeks at the earliest. Sharon should only be in the fifth to sixth week at the most.

* Dem Bones song [[http://www.kididdles.com/lyrics/d009.html found here]] (warning for sound)
** "...the toe bone's connected to the heel bone..." [Nope, there's metatarsals and other tarsals in between.]
** "...the thigh bone's connected to the backbone..." [Also nope, there's a little thing called a ''pelvis'' between them.]
** "...the neck bone's connected to the head bone..." [No such thing as "the" neck or head bone: both head and neck have several.]
** Depending on how you look at it, either ''very few'' bones are actually "connected" to other bones, or ''all'' of them are connected to ''all'' the others (the various skull bones are pretty clearly connected to each other, as are the fused bones at the other end of the spine; other than that, they mostly just hang out near each other and are connected only by soft tissue without actually touching).
* In the children's song "I'm Being Eaten By A Boa Constrictor", the snake swallows its prey feet-first. This is backwards from how snakes normally feed (granted, doing it the right way around would make for a much shorter song...) Another problem with the song is that boas kill their prey ''before'' they start to swallow it.
* The otherwise, accurate ''Music/TheyMightBeGiants'' song, "Mammal", which explains the common traits of various mammals, as well as lists several different examples... that is until they list koala "bears", which are actually marsupials, not bears.
* "Worlds Within The Margins" by ''Music/InFlames'' contains the line "coded within the spinal cord of the trilobite". Trilobites were invertebrates, they did not have spinal cords.

[[folder:Pro Wrestling]]
* Back in Stampede Wrestling, [[Wrestling/DynamiteKid the Dynamite Kid]], a {{Heel}}, was feuding with Wrestling/DaveyBoySmith. Dynamite took a rather, to put it mildly, ''unique'' approach to generating heat for the feud. He and manager JR Foley[[note]]John Foley, no relation to those [[Wrestling/JimRoss other]] [[Wrestling/MickFoley guys]][[/note]] were being [[http://www.youtube.com/watch?v=ziv6MnVIRQg interviewed]] and Dynamite claimed that Davey Boy was a test tube baby, but that's not the unscientific part. The unscientific part was Dynamite saying that Davey being a test tube baby meant that he wasn't human and that he should "go back to Jupiter or Mars."
* Black Tiger's mask having silver stripes is clearly for artistic purposes. Real black tigers have black stripes, with the "stripes" being thicker areas of fur. But that's not so visible to those in the cheap seats, is it?

[[folder:Tabletop Games]]
* Creator/WhiteWolf's ''Aeon Trinity'' contains the following gem: "[Psions are] the product of natural human evolution, not genetic mutation." This was later retconned to refer to mankind's ''spiritual'' evolution.
* ''Tabletopgame/DungeonsAndDragons''
** All human/tiefling descendants are tieflings. Forever. Nobody ever finds a tiefling hiding unknown in their family tree; oh no, if your great-grandfather is a tiefling so is everyone descended from him. Apparently when devils are involved, Mendel's laws are more like suggestions. Depending on the sourcebook, some tried to correct it to "half-demon for a few generations, tiefling for a few generations, human eligible for Demon Bloodline feats", judging by the various sourcebooks on the subject (and depending on who you mate with).
*** As of 4th edition, though, tieflings are back to having supernaturally [[InTheBlood tainted blood]], rather than a genetic condition; the first tieflings were the result of normal humans undergoing an infernal ritual, rather than interbreeding with demons.
*** The ''Literature/BrimstoneAngels'' novel series offers a further clarification for the TabletopGames/ForgottenRealms setting; thanks to a powerful ritual, all tieflings are, spiritually, considered descendants of [[SatanicArchetype Asmodeus]] regardless of their actual lineage. Since Asmodeus is a god, his power is just that virulent and natural laws really ''are'' just guidelines as far as he's concerned. That said, tieflings with a lot of human blood are still depicted as being somewhat more human looking than those who are closer to the fiendish end of the family tree.
** Some D&D examples of this trope don't even have AWizardDidIt as an excuse. One of the Mystara setting's supplements featured a former underground empire of gnomes, now abandoned and infested with kobolds, various dungeon vermin, and wild herds of fungus-grazing ''mules''. The mules were supposedly the feral descendents of the gnomes' mule beasts of burden. While female mules may not be [[ConvictionByCounterfactualClue 100% sterile]], fertile ''males'' are so rare that the only evidence of such creatures is anecdotal, making a wild population of mules virtually impossible even on the surface, never mind underground!
** Fungal enemies, such as the shrieker or violet fungus, are generally listed as belonging to the Plant type. "Plant" and "fungus" are mutually exclusive -- in fact, fungi are more closely related to ''animals'' than to plants.
** The rules for creatures that can [[SwallowedWhole Swallow Whole]] say that if a swallowed opponent manages to cut their way out of the stomach, "muscular action" will force the hole shut behind them. Of course muscles don't work like that, but the rule was instituted as an ObviousRulePatch to keep the creature from becoming little more than a really macabre water slide.
* ''TabletopGame/{{FATAL}}'' allows for completely out-of-whack character biology. Would you like to have nipples the size of your head and an anus with negative circumference? Equally silly is being able to hit a very specific internal organ AND NOTHING ELSE on the enemy; to quote [[http://www.rpg.net/reviews/archive/14/14567.phtml one of the more infamous reviews]]:
-->"The two stared at each other, then struck simultaneously. Jack's sword cleaved through the cultist's chest, cleaving through the nipple, the xiphoid process -- the lowest part of the sternum -- and the shoulder blade. The cultist's blade only caused damage to Jack's appendix and his adrenal gland, somehow missing everything else in front of and in back of Jack's adrenal gland and appendix."
** Having your heart torn out kills you in two rounds, which is ''slower'' than [[GroinAttack having your testicles cut off]], which with a failed save will kill you instantly. Exactly why the creators of FATAL consider the testicles more vital to life than the heart is left as an exercise for the reader, one you probably don't want to solve. Considering the sophomoric sensibilities of the creators, it's possible that they personally value their testicles more than their hearts.
* In FGU's ''Space Opera'', a character who has died can be injected with "TKM"; a drug that stops cell decomposition. But the drug reaches the whole body via circulation, a function that stops at the moment of death.
* Two specific cases in ''TabletopGame/{{Rifts}}'', listed separately:
** In the Atlantis Sourcebook, a parasite called a Brain Feeder is said to "...excrete a chemical that anesthetizes the area of the brain it is eating..." This would be unnecessary, as there are no pain receptors in the brain, and therefore it can't feel pain.
** This one could well be a case of ScienceMarchesOn. There is an animal race in the books called an Ostrosaurus, which is not a dinosaur but "a large featherless bird." According to modern paleontology, birds are dinosaurs.
** The description of dragons says that they are actually mammals, not reptiles, even though they are scaly, hairless, egg-laying creatures that don't produce milk.
* In ''TabletopGame/{{Warhammer 40000}}'' science generally takes a backseat to the RuleOfCool, but...
** One particularly JustForFun/{{egregious}} example needs to be mentioned: The Eldar are stated to have [[BizarreAlienBiology TRIPLE HELIX DNA]][[note]]which DOES technically exist, but is considered very unstable[[/note]] and are ''somehow'' still hinted to be capable of birthing a viable human/Eldar hybrid, the sole example of which is one of the Ultramarines. This has since been retconned out of existence. The fact that female Eldar may have ample chests even though Eldar have literally not a single gramm fat in their bodies is almost tame in comparison.
** The Kroot. Mostly blank DNA, and they evolve very rapidly by incorporating DNA from everything they eat into their genetic structure. Now answer us this: if their DNA is "blank", how do their embryos form into Kroot in the first place? Definitely a case of 'well, it sounded cool when I wrote it''.
** Ork DNA, in past editions, contained an "algal base" that explained their resilience. This made no sense whatsoever and was dropped; now their DNA just happens to be very, very similar to algae, to the point where they can photosynthesize.

* Occurs sometimes in the Toys/BeanieBabies plush toy line:
** A weasel-like Beanie named Runner has ''mustelidae'' officially listed as its species. The poem suggests that it could be "a ferret, mongoose, weasel or mink." Although the other three species are legitimately mustelidae, mongoose are kind of on their own classification-wise, and are actually more closely related to felines and hyenas than anything else. This research lapse may have something to do with the "[[http://www.aboutbeanies.com/Tag_Errors.shtml mean poem]]" that the toy was originally released with (itself a CrowningMomentOfFunny for the franchise), which identified it as a mongoose.
** Seaweed the Otter is depicted with seaweed in her paws, as if she were eating it. Sea otters eat largely eat marine invertebrates and fish. While sea otters do sometimes wrap themselves in seaweed, the purpose is to anchor themselves while they sleep.
* From ''Toys/{{Bionicle}}'': According the Greg Farshtey, the Makuta "evolved" into antidermis. However, if the Makuta were originally ''meant'' and specifically engineered by the Great Beings so that this would happen, this would make it simple metamorphosis.
** Greg Farshtey has addressed his use of the term "evolution." Because natives of the Matoran Universe don't biologically reproduce, such changes are referred to as evolution. In the story's final days, it was revealed that dead beings are send to the Red Star for healing and repairs, but a malfunction kept them from returning.
* Franchise/{{Bratz}} has "'Lil Angelz" veterinarian toys, including pets who get sick. The problem? You take their temperature orally. That's passable, for a children's toy, but the animals' temperatures are at normal ''human'' temperatures -- as opposed to their actual regular temperatures.
* [=FurReal=] Friends has a line of baby animal animatrons that you feed fake milk. Unfortunately, that line contains a duck and a parrot. When did baby birds start drinking milk?

[[folder:Video Games]]
* In ''VideoGame/AmnesiaTheDarkDescent'', When Daniel has to (quoting Wiki/TVTropes here), "drill a hole in the head of ''a corpse,''[sic] insert a copper tube into the hole, and stick yourself on the needle to give yourself an injection of a vaccine." God only knows if they're the same blood type or how long the body's been dead, if he had any infectious diseases, or if the antibodies have degraded and are no longer viable. Somewhat {{justified|Trope}} since the game takes place in 1839. Blood groups weren't starting to be identified until 1901. How blood-borne pathogens work and the intricacies of vaccinations was also not as well understood at the time.
* In ''VideoGame/{{Borderlands 2}}: Mister Torgue's Campaign of Carnage'', BigBad [[ArrogantKungFuGuy Piston]] mocks the Vault Hunter throughout the main story missions. At one point, he claims to have less than one percent body fat and thirteen pecs, which earlier laughed at the Vault Hunter.
* ''VideoGame/DonkeyKongCountry'':
** Diddy Kong is often called a chimpanzee (and, in some instances, referred to as Donkey Kong's nephew), even though he has a tail.
** Cranky Kong is explicitly [[VideoGame/DonkeyKong the original DK]]. He was a gorilla then. He's currently somewhere between Chimp and Baboon, with a demonstrably different bone structure, body shape, set of limb proportions, and cranial shape. MiniatureSeniorCitizens as applied to non-human primates?
** An IGN article identifies Diddy Kong (who, again, has a tail) as an "ape", and then goes on to say that Lanky Kong is "not an ape, but an orangutan". Orangutans ''really are'' apes.
* The final mission of ''VideoGame/Hitman2016'''s Season One brings you to the most advanced hospital in the world, where one of 47's targets, a person who suffers the condition Situs Inversus (Mirrored organs), is about to have a heart transplant. 47 can destroy the mirrored heart that was meant for him, which, in theory, dooms him to die at the operating table because mirrored hearts are extremely rare and they would have no time to find another. In practice, however, patients suffering from Situs Inversus can receive non-mirrored organ transplants. The operation is a lot more complicated but, again, we're talking of the most advanced hospital in the world...
* Ironically, an Edutainment game -- though, thankfully, it wasn't one that teaches biology. ''VideoGame/JumpStart Spelling'' features some cavemen mistaken Edison Firefly for fire. And yes, his abdomen gives off heat.
* Like most SpaceOpera settings, ''Franchise/MassEffect'' takes quite some liberties, like most sapient alien species bearing a humanoid bauplan or resembling earth reptiles, arthropods and amphibians in biology. However, two examples stand out:
** The presence of ''fish'' on many worlds. As in, bony fish classiable as such.
** A rather unfortunate misunderstanding of dextro-amino acids. See MirrorChemistry for more information.
* ''VideoGame/MetalGearSolid'':
** The whole business where the Les Enfants Terribles twins were created as double-dominant and double-recessive ''for absolutely no reason'' other than to give Liquid Snake something to obsess over. And no, you can't be a homozygous recessive individual because the term is meaningless outside a breeding population.
** Even if he could have all of Big Boss' recessive genes, there is nothing about this that would make him inferior. Really, this troper learned in ''fifth grade'' that a gene being recessive simply means it will be overridden by a gene that is dominant to it, which is not the same as saying the dominant gene is better.
** There's also the part where Liquid grossly misapplies Asymmetry Theory. His ramblings just make it seem like the writers had at some point heard of the biology/genetic concepts mentioned, but didn't actually bother to look into them any real way.[[note]]WordOfGod is that Liquid, personally, has no grasp of how genetics works, and was deliberately taught wrong just to wind him up and make him driven.[[spoiler:''VideoGame/MetalGearSolidVThePhantomPain'' even reveals that he failed Biology as a subject, despite supposedly having an IQ of 180.]][[/note]] Then there's the guy whose body carries a charge of 10 million volts, the man who can't decide if his pet internal beehive is full of bees or hornets...
** It's also later revealed in ''VideoGame/MetalGearSolid'' that it was actually ''Liquid'' who got all the dominant genes, and Solid got the recessive ones. One problem - Liquid Snake is blond. The gene for blonde hair is recessive. Similarly, Snake has brown hair, when the "brown hair" gene is the dominant one. If Liquid really got all the dominant genes and Solid got all the recessive ones, then Solid should be blond and Liquid should be brunet.
* ''VideoGame/MetalGear2SolidSnake''. Four words. Deadly poisonous Zanzibar hamsters.
* In ''[[VideoGame/MetalSlug Metal Slug 3D]]'', there's a scene when Rumi tells Marco that carbon dating estimated that an alien ruin Marco was exploring was 8 ''billion'' years old. Even bypassing RagnarokProofing, carbon dating will only work on artifacts less than 60,000 years (or so) old. Other methods of testing radioactive decay are necessary for something far older. The alien ruins are well on their way to being twice as old as the Earth (4.6 billion years old).
* Apples in ''VideoGame/{{Minecraft}}'' are harvested from ''oak'' trees. This is, admittedly, because they started as plain oak trees that didn't have any fruit, and the apple drop was added later, but you'd think Mojang could have at least renamed them.
%%* ''VideoGame/MonsterHunter'' features a ridiculous number of monsters; some of which, admittedly, could have existed on this or some other planet. Many of them, however, cause Capcom to adhere to this trope -- the world on which the game takes place presumably has similar atmospheric conditions and gravity, and yet... the Deviljho...%%Zero-context example. How is the Deviljho an example of this trope?
* ''Franchise/MortalKombat'' is very guilty of this, especially in the 3D games: Rip out a brain, the body is still standing AND feeling pain; rip out a skull, and the head still has shape; rip out your own tibias, and you're still standing; sever someone's head, and the body is still standing; the list goes on...
** Lampshaded in ''VideoGame/MortalKombat3'', where certain Fatalities could cause several of the same thing to get ripped out, including multiple hearts, rib cages, and skulls. Also, most often these were ripped out through the chest. Yes, even the skulls...
* In ''VideoGame/MoshiMonsters'', the chimpanzees have tails.
* ''VideoGame/NetHack'' variant ''VideoGame/SlashEmExtended'' has goats and other mammals that lay eggs.
* In ''VideoGame/{{Nintendogs}} + Cats'' each breed comes in multiple colours, however in real life many of the breeds have very few, if any, varying patterns according to Breed Standards. This means several dogs have fake fur colours, such as Malteses with spots.
* Deliberately invoked for horror in ''VideoGame/{{Outlast}}: Whistleblower''. Eddie Gluskin, a psychotic SerialKiller even before his MindRape in the illegal underground lab below the Asylum, is fixated on finding himself a perfect bride. In response to being surrounded only by men, he's come to the conclusion that as the only major difference between genders is that men have a penis & testicles whilst women have a vagina, and as the vagina looks a lot like a cut, [[GroinAttack brutally castrating men and using the resultant wound as a vagina]] will make them fully functional as women, complete with [[MisterSeahorse bearing his much-wanted children]]. Needless to say, it does ''not'' work that way, but he's so demented that he refuses to accept that he's doomed to fail.
* ''Franchise/{{Pokemon}}'' :
** Several of Cubone's Pokédex entries state that it wears the skull of its mother. Every Cubone encountered has a skull on its face, which means that EVERY SINGLE Cubone commits matricide (or its mother just dies) shortly after birth and each female Marowak/Cubone can only have one child. The species should have either died out or have rapidly dwindling numbers at this point. However, worth noting is that when breeding Cubones, you can get as many of them as you want from one mother, and they will all already have skull helmets. Additionally, in ''Anime/PokemonOrigins'' a Cubone is seen with its alive mother Marowak, and yet it has a helmet. These suggest that this Pokedex "fact" is either not true or has since been retconned.
** The Pokédex also states that Vaporeon's "cell composition is similar to water molecules. As a result, it can melt away into water." A cell is a lot more complex than a three-atom molecule. Even if we assume this to be a mistranslation that should read something like 'its cells are composed mostly of water', then we (and everything else alive) could too.
* ''VideoGame/RedDeadRedemption'': A rare example of simple mistakes than mismanagement of biological knowledge. In some cases random glitches or hacks allow you to ride other animals that are often used for hunting challenges. However, they still gallop and neigh like horses (as well as floating inches off the ground)- including the [[http://www.youtube.com/watch?v=yeJSfVmeKDU elk]], [[http://www.youtube.com/watch?v=W75tiaN0uCA wolf]], [[http://www.youtube.com/watch?v=ycGiIxlzZGc grizzly bear]], [[http://www.youtube.com/watch?v=PS1qGWlOYns cougar]], [[http://www.youtube.com/watch?v=tSrmRHJKc3A deer]], [[http://www.youtube.com/watch?v=l_8P6W9dFf4 bobcat]], [[http://www.youtube.com/watch?v=AK_6Ns87_wU dog]], and a [[http://www.youtube.com/watch?v=SvY2W3HOJ4M jack-rabbit]]. Others were more intentional. For example pumas don't sound like [[http://www.youtube.com/watch?v=Bt8hwLlSyvo jaguars]]. In fact they don't roar at all, but growl, hiss and make [[http://www.youtube.com/watch?v=xKw4OFAu1WM snarly near-human screams]].
* ''Franchise/ResidentEvil'': [[UpToEleven Where to even begin?]] Viruses that jump species like they're on a trampoline, a single strain that triggers all kinds of mutations depending on the host, people that explode into building-sized masses of limbs and tentacles in seconds, giant arthropods who somehow don't suffocate to death, a modified gene that kills weaker cells "through natural selection" to somehow empower the carrier, mind-controlling parasites with a caste system, monsters with '''biological machine guns and chainsaws,''' and all of this is tied back to a rare flower that produces a gene-altering virus, but only if it's in a very specific location in Africa.
* In ''VideoGame/{{Ripper}}'', the killer is revealed as hacking people's minds/brains to program their bodies to self destruct. While there are ways to theoretically kill someone if you interface with their brain, the Ripper somehow increases the internal body pressure to cause them to explode from the inside. ''Somehow'' the forensics investigators keep thinking the killer is killing by slicing people up with a knife, which would look ''nothing'' like exploding from within, even assuming programming your body to explode was possible.
* In ''VideoGame/Sly2BandOfThieves'', one of Bentley's plans works on the assumption that tigers dislike water. In real life, tigers are one of the few known types of cat who ''like'' to get wet. Also in the ''Franchise/SlyCooper'' games, Bentley (a turtle) and Murray (a hippopotamus), both aquatic creatures, are incapable of swimming, [[SuperDrowningSkills instantly drowning]] upon contact with a body of water.
* ''VideoGame/{{Starcraft}}''. For a series that goes to great length to explain how everything works, the powered marine armour really shouldn't require multiple shoulder dislocations... Arguably explained and justified by the opening cinematic for Starcraft II. Though that depends on whether you believe Tychus Findley's build is at all realistic.
* ''VideoGame/StarOceanTheLastHope'' features a number of baffling evolutionary presumptions. For instance, there are apparently "right" and "wrong" ways to evolve, and we should "make our hearts worthy" of evolution. Edge Maverick must not hold protozoa in very high regard. Edge, sweetie, that's "cultural development" and "reaching a specific level of technological advancement (specifically interstellar travel) within that culture" you're thinking of, not evolution, the two are ''almost'' entirely unrelated.
* ''VideoGame/WarioMasterOfDisguise'' has a dolphin boss who breathes water instead of air, and the way to beat it involves trapping it above water so it gasps like a fish. [[SarcasmMode Because dolphins are obviously fish.]]
* ''VideoGame/TheWitness'': Out of all the rooms inside the greenhouse, the one with green light is probably the most prominent: it provides the main difficulty for the elevator puzzle, it's harder to reach compared to the other rooms, it contains an audio log and an environmental puzzle, and it's the only one which can be seen from the outside. It's ironic that the green room was chosen to be this way, considering it's also ''the most unrealistic''. Chlorophyll absorbs light throughout the visible spectrum, but mostly in the blue and red regions and very little in the green region (in fact, of all the many pigments that plants use to absorb light, none of them absorb much green light).[[note]]This is actually a form of protection. The sun gives off the most amount of its energy as visible light in the green region of the spectrum (483-520 nm). Chlorophyll is easily destroyed by too much energy, and when the pigments break down and stop absorbing light entering the plant, that energy can cause damage to other plant tissues as well, including the plants DNA. Think of it as a sort of plant sunburn.[[/note]] Plants ''look'' green because they ''reflect'' green rather than use it.
* ''VideoGame/WorldOfWarcraft''
** The devs don't know how horses run (the game animates them the same way as a cheetah, with legs outstretched in the suspension phase instead of collected). But is it a big enough deal for the devs to correct it? [[BellisariosMaxim Not really]].
** Elekk (a pseudo elephant mount) freakin' ''gallop''. Come to think of it, so do the mammoths. Knee joints of adamantium!
** The wolf mounts, and by extension all wolf mobs [[http://www.free-wow-guides.com/image-files/world-of-warcraft-mounts-black-wolf.jpg using the worg model]] run nothing like an actual wolf would run. Wolf mobs using [[http://www.wowhunterpets.info/images/models/fs_wolfskinblack.jpg the alternative wolf model]] run properly.
** Orcas apparently produce humpback whale song. When fighting, no less.
* ''Franchise/SonicTheHedgehog'' has a few inaccuracies, though most can be forgiven since these are anthropomorphic sentient talking animals who bear little if any resemblence to what species they're actually supposed to be:
** Sonic's inability to swim was due to Creator/{{Sega}} thinking real hedgehogs couldn't swim, when they actually can.
** Sonic's favourite food is chili dogs, which are mentioned in ''VideoGame/SonicUnleashed'' as being quite spicy. Humans are the only animals who willingly eat spicy foods, as spiciness is supposed to be a ''deterrent'' that plants use to stop animals from eating them.
** Sonic's best friend is a fox. In real life, foxes eat hedgehogs.
** Even ignoring the biological impossibility of a fox being born with two tails, there is no way, anatomically speaking, that Tails should be able to spin his tails like a propeller to lift himself into the air the way that he does - spinning both tails in the opposite direction, which would just result in them getting twisted together. And even if he did spin them in the same direction, it's very unlikely he'd be able to spin them fast enough to actually provide enough lift to get his body off the ground.
** In ''VideoGame/SonicUnleashed'', a RunningGag is Chip offering chocolate to whomever he meets. This includes Tails (a fox) and a phoenix (a giant bird). Chocolate is very bad for animals. Notably, Sonic is also able to consume chocolate, ice cream, and other things that would make a real hedgehog very sick, if not outright kill them.
* ''VideoGame/Splatoon2'': PlayedForLaughs. Within the game's lore, whatever wins a Splatfest competition is legally the "correct" choice. Most are simple things like "Which is better: ketchup or mayonnaise?" however one was "Which came first: the chicken or the egg?". Pearl believes it was the chicken and Marina believes it was the egg. Chicken ended up winning. After losing, Marina notes that most scientists believe that the egg came first, but Pearl won't listen and says that the law is the law.

[[folder:Visual Novels]]
* The Cure Virus in ''VisualNovel/Ever17''. Willing suspension of disbelief can take you a pretty long way... but a natural retrovirus that not only rewrites the host to be immortal and have a HealingFactor? Maybe that one can slide. But with no apparent benefit to itself and also apparently ''adapting'' itself to give [[spoiler:infrared vision]] to cover the inability to cope with UV rays and therefore be unable to go out when it's not dark? Don't think so! Retroviruses are not magical, intelligent and they do not change DNA for the benefit of their host. Odds are, however, that the Cure virus isn't natural. [[spoiler:Leiblich ''was'' researching virus engineering, after all. It would explain how and why they knew Tsugumi had been infected at all. They infected her. Then, they studied her to try and find out what was about her that made the virus work.]] ''VisualNovel/Never7'' reveals that [[spoiler:the Cure Virus was created as a result of a Cure Syndrome delusion, so the "magical" part of the virus can be explained that the virus adapted itself to work in a human's body that way]].
* In ''VisualNovel/SteinsGate'', [[spoiler:Lukako's sex]] is changed by making the mother eat a lot of vegetables instead of meat. This is {{lampshade|Hanging}}d as being an old wives' tale, and none of the characters really think it will work... so they are extremely surprised when it apparently does.

[[folder:Web Animation]]
* In ''WebAnimation/CowOfTheWild'', Rune's distinctive scar supposedly resulted from the pupil of his eye being ripped out. The pupil is a ''hole in the iris''. Just think about that for a minute.

[[folder:Web Comics]]
* ''Webcomic/GeorgeTheDragon'' has a sword fighting scene where the duelists have an improbable Darth Vader/Luke Skywalker moment. [[http://www.drunkduck.com/George_the_Dragon/index.php?p=502824 "Lobster, I am your Fish"]]
* ''Webcomic/MenageA3'': [=DiDi=]'s breasts defy the laws of both biology and physics -- despite having ''enormous'' natural GagBoobs, they not only fail to sag ''at all'', but are completely spherical, with the nipple appearing on the upper-third of the breast. A RuleOfSexy here, as Gisele almost ''never'' draws breasts as anything but round and perky.
* As referenced above, [[VideoGame/MetalGearSolid Liquid Snake's]] appalling grasp of biology is repeatedly referenced and mocked in ''Webcomic/TheLastDaysOfFOXHOUND''. It actually explains that the entire dominant / recessive genes thing was complete rubbish, and that Liquid was told he was the inferior one as a part of installing a massive inferiority complex in him, so he'd constantly keep on pushing himself to do better. And then it turns out to be a DoubleSubversion, because Big Boss explains that it was actually Solid that got all the "recessive genes." It isn't just Liquid's grasp of genetics; it's Hideo Kojima's that's so hilariously wrong. Subsequently {{lampshade|Hanging}}d when Liquid consults the American Journal of Inaccurate Genetics.
* In the world of ''WebComic/OffWhite,'' humans normally can't have blue eyes at all. This is necessary for the plot to work, because White Spirits are indicated by their blue eyes. If humans could have blue eyes in this comic, they would have no way of knowing that the human White Spirit is gone, something that drives much of the plot.
* Actually averted in ''Webcomic/TheOrderOfTheStick'' #921, though in a bit of a misleading way: Vaarsuvius' familiar refers to pteranodons as "clade brothers". While pteranodons are not the precursors of modern birds, they do share the clade Archosaura. But then, in cladistics, almost any two organisms can be part of the same clade if you go back far enough. Lions and Tigers are part of the clade Felidae; dogs and cats Carnivora; cats and monkeys Mammalia; and so on.
* In ''Webcomic/{{Teahouse}}'' the brother-sister twins Remy and Rory are said to be identical even though that's impossible for a brother and sister pair. WordOfGod claims they did this on [[http://s23.postimg.org/fnin1zdij/image.png purpose]].
* Downplayed in ''Webcomic/ContestJitters''. Janet is very buff for a natural bodybuilder, but her trainer did comment that she had the genes for it. It is also shown that she works very hard at weights.
* In general, it's missing the point to complain about biological inaccuracy in FunnyAnimal media, but ''Webcomic/KevinAndKell'''s take on Dolly the Sheep gets deep into some real life misconceptions about Dolly and cloning in general. At one point, Dolly begins ageing at an accelerated rate, going from a teenager to middle-aged overnight. While there was some speculation that this was the reason for the real Dolly becoming sick and needing put down at half the typical lifespan of a sheep, it was eventually concluded that there was no evidence to support this. Also, the thinking behind this speculation was that Dolly's cells might have started out at the "same age" as her donor-mother, but in ''Kevin and Kell'', Dolly (like most fictional clones) is ''already'' the same age as the donor (Corrie Dale), and the increased ageing makes her noticeably ''older'' than Corrie.
* ''Webcomic/MountainTime'' plays it in-universe, with [[http://mountaincomics.com/comic/mt747/ two characters arguing nonsense biology]].
* ''Webcomic/StandStillStaySilent'': The pregnancies of a couple characters from the JustBeforeTheEnd prologue come across as having happened quite late in their lives:
** Ingrid downplays it: looks to be in her very late teens or early twenties in Year 0, her son Trond is 67 in Year 90. That puts her pregnancy somewhere between her late forties and early fifties, the time around which most women get hit with menopause.
** Mia is a straighter case: she looks around 10 in Year 0, but her son Torbjörn is only 38 in Year 90. Even lower estimates of her age make her get pregnant with him past the 55 year mark.

[[folder:Web Original]]
* Blog/CakeWrecks often features things that are supposed to be cake-and-frosting representations of people. Most of them are anatomically implausible at best, often involving boneless limbs, off-centre faces, and oddly contorted positions.
-->"Last time I checked, turtles don't walk around facing the sky."
* [[RuleOfFunny Played for laughs]] by Website/{{Cracked}}: " It's like every single AC/DC album cover came to life and punched your eyeballs right in the dick." Read more: [[http://www.cracked.com/blog/7-images-too-badass-to-be-real-that-totally-are/#ixzz1OqUf7vGr 7 Images Too Badass To Be Real (That Totally Are)]]
* In ''Roleplay/SurvivalOfTheFittest'', during V1 in particular, there were examples of writers who decided to eschew any pretence of realism in their kills. Later versions have done their best to avert this. A particularly...[[http://z10.invisionfree.com/SurvivalOfTheFittest/index.php?showtopic=425 interesting example.]]
* Keith Thompson's ''[[http://www.keiththompsonart.com/pages/ghoul.html Ghoul]]'' seems to depict [[http://en.wikipedia.org/wiki/Kuru_%28disease%29 Kuru]] as the complete opposite of what it really is: rather than slowly turning destroying the physical and mental capabilities of its victims as it does in RealLife, Keith Thompson's Kuru [[OurZombiesAreDifferent zombifies]] them. However, he has [[ShownTheirWork Shown His Work]] in that both versions of the disease are transmitted by eating infected corpses.
* The flash clip ''[[http://www.weebls-stuff.com/songs/dugong/ Dugong]]'' begins with words 'Dugong, dugong it's a cow of the se-e-e-a. Dugong, dugong, also known as the manatee'. The problem is that dugong (''Dugong dugong'') and manatees (genus ''Trichechidae'') are different animals. One may also argue that 'sea cow' (a common name for dugong) is yet another, now extinct animal also known as Steller's Sea Cow (''Hydrodamalis gigas''). Furthermore, the song contains the phrase 'Compared to dolphin, its very close cousin...'. Dugong and dolphins are water mammals, but they belong to different orders (dugong to ''Sirenia'', dolphins to ''Cetacea''). Hardly 'very close cousins'.
* An [[http://www.theguardian.com/news/datablog/quiz/2014/aug/14/a-levels-how-big-vocabulary online quiz]] by the UK ''Guardian'' newspaper claims that "colubrine" means "of or relating to snakes". It doesn't; it means "of or relating to one particular type of snake". The word they were looking for is "ophidian".
* WebOriginal/JeffTheKiller has a severely burned face, a GlasgowGrin, and severed eyelids, the last two of which are self-inflicted. This does not impede him in any way, even though such injuries would lead to blindness and death by sepsis in RealLife.
** Not only that, but after being covered in bleach and alcohol, then set on fire, all that happened was Jeff's face was bleached white. The actual results would have been [[BodyHorror far, far more gruesome]].
* {{Lampshade|Hanging}}d by the ''Webvideo/AngryVideoGameNerd'' in his review of ''Little Red Hood.''
-->'''Nerd:''' The only thing the kick can be used for is kicking palm trees to make cherries appear. But please God, tell me one thing: ''Why are there '''cherries''' coming out of a [[PrecisionFStrike fucking]] '''palm tree'''?!'''
* [[http://www.fstdt.net/QuoteComment.aspx?QID=25750 "As far as I know I wasn't an egg. I don't believe human beings lay eggs do they?"]]
* Lampshaded [[http://xninjared.deviantart.com/art/The-Mermaid-Problem-155487940 here]] about Mermaids.

[[folder:Western Animation]]
* Many cartoons or drawings portray coconuts as hairy, brown balls hanging from trees. In real life, coconuts are green or yellow and have smooth surfaces; the brown, hairy part usually seen is actually the endocarp of a coconut.
* The wide majority of cartoons that draw octopi and squid with their mouths on the front of their bodies or on their foreheads, with said mouth being lipped. The cephalopod mouth is located in the centerpoint of the arms, and all extant cephalopods possess a two-point beak similar to a bird's.
* ''WesternAnimation/TheAdventuresOfJimmyNeutronBoyGenius'':
** An episode involves extracting mitochondria from a virus. Viruses aren't cellular and don't have cells, and by extension don't have mitochondria.
** In "The Eggpire Strikes Back," Jimmy states that, because Cindy extracted the secret to entering his lab from Carl and Sheen and betrayed him to the Yolkians, that he's going to erase her short term memory so that she forgets. Thing is, this had happened the day before, so unless Cindy didn't sleep the knowledge would already have been consolidated into long term memory.
* ''WesternAnimation/Ben10'':
** In an episode, some cows and a human were turned into mutant monstrosities due to exposure to an alien mutagen. Fortunately they were "only briefly exposed", so the mutation reversed itself by the end of the episode.
** The sequel series ''WesternAnimation/Ben10AlienForce'' features numerous human/alien hybrids, biologically impossible enough on its own. One of these has a nonhuman parent of a species ''made of fire''.
* In an episode of the short-lived ''WesternAnimation/TheBuzzOnMaggie'', Maggie's older brother zaps her with a hand buzzer, resulting in XRaySparks. For those who have never heard of the show, it's a high school comedy involving ''insects''. Insects do not have inner skeletons.
* WesternAnimation/ChipAndDale both have dog-like noses and short deer-like tails, something real chipmunks do not have.
* In the ''WesternAnimation/CourageTheCowardlyDog'' episode "The Magic Tree of Nowhere", when Eustace accidentally wishes for Muriel to come down with an illness, Courage is tasked with making a cure with honey from a [[BeeAfraid hornet's nest]]. While some species of hornets and wasps can make honey, it's only produced in small amounts and is not fit for human consumption.
* In ''WesternAnimation/DannyPhantom'', failed cloning resulted in a [[DistaffCounterpart female, younger version of Danny, named Danielle]], who would [[CastFromHitPoints devolve into ectoplasm]] if she used her powers. She got better. Cloning ''should'' produce a younger version, just a fair bit more so than the cartoon likely portrayed. The entire thing was an obvious reference/homage to the '90s Clone Saga from ''Franchise/SpiderMan'', which similarly botched cloning in many, ''many'' ways.
* Done in ''WesternAnimation/TheFairlyOddParents'' episode where Timmy's Dad's first time on the ''Series/AreYouSmarterThanAFifthGrader'' spoof, "Are You Brighter Than a 6th Grader" had him answer "sea cucumber" to nearly all the questions until the last one, "what kind of cucumber lives in the sea" prompting him to say the wrong answer. Forcing himself to re-attend school, Timmy's Dad retakes the competition and goes on a roll until the last question, "which sea vegetable would suit perfectly on an undersea salad", causes him to hesitate until he find it in himself to say the right answer. In spite of the name, sea cucumbers are ''not'' cucumbers or vegetables in general, but animals -- specifically echinoderms, like starfish. ''Regular'' cucumbers aren't technically vegetables, even.
* ''WesternAnimation/FamilyGuy'':
** Most of the jokes based on Joe's crippled status fall under this. Anyone who knows ANYTHING about paralysis knows the problem isn't the legs, it's the ''damage to the spine'' that keeps the legs or anything below the damage from being used. Leg transplants wouldn't repair the damage at all, correcting the damage to the spine would. Even stranger in that in one episode when he was cured, he got re-paralyzed by a gunshot wound to the lower back, and they also make a lot of jokes about how nothing else below the waist [[ToiletHumour works very well]]. Like most things on the show, Joe's paralysis mostly seems to run on RuleOfFunny. Never mind the UnfortunateImplications of all the cripple jokes.
** At the end of the episode "Quagmire's Quagmire", Quagmire gets a call from his male-to-female father saying that she's pregnant. As explored on ''WesternAnimation/SouthPark'' when Mr. Garrison got a sex change, his father wouldn't be able to carry a child because the surgery wouldn't have given her the organs needed to do so.
* ''Franklin and the Green Knight'', a film from the ''Literature/{{Franklin}}'' series depicts Mrs. Turtle, an anthropomorphic turtle, as being pregnant with Franklin's sister, Harriet, rather than laying an egg. Franklin can also remove his shell in the cartoon series. In reality, a turtle's shell is fused to its spine and ribcage. Even if it were possible to take it off, attempting such an act would kill the turtle in a very messy way. (While we're on the subject, someone should remind a [[http://friskywoods.deviantart.com/art/Shellshocked-77703850 certain Italian plumber]] of this.) This is averted in the follow-up series ''Franklin and Friends'' in which not only can neither Franklin nor any of his family remove their shells, but it's also said at least once that the shell grows with them.
* ''WesternAnimation/{{Futurama}}'':
** Fry apparently survives a temperature of ''109 degrees''. Normally, people die if their body temperature reaches ''108'.
** Zoidberg is seen shivering as he claims he's cold-blooded. Cold-blooded animals don't shiver when cold.
** The crocodiles seen in "I Second That Emotion" have overbites like alligators, instead of interlocking teeth. On the other hand, the alligators from "The Series Has Landed" are properly drawn with overbites, though their skin is green instead of black or gray.
** Rabbits and hares are drawn with noses more like a cat's or a dog's than actual rabbit noses.
** From "Fry and Leela's Big Fling":
*** The proboscis monkeys are drawn [[InexplicablyTailless without tails]].
*** Many of the chimpanzees have their fur colored brown (real chimps all have black fur).
*** The gazelles in the zoo have body shapes and faces more like those of a deer than an actual gazelle.
** The toucan seen in "Meanwhile" has three toes in front and one in back. Real toucans have two toes in front and two in back like parrots, which in this series are drawn with only one toe in back.
** One episode involved the auctioning-off of the last extant tin of anchovies, a species which had gone extinct centuries before. There is no such species as "anchovy", as it's a catch-all term for any of ''144 species'' of small fishes.
* One episode of the 2007 version of ''WesternAnimation/GeorgeOfTheJungle'' has a rhinoceros skeleton with the horns still intact as if they were bones. A rhino's horn is made up of keratin, so when the animal dies it would have rotted away with the flesh if not quicker.
* Among the many errors regarding animal physiology and behavior, one of the more minor in ''WesternAnimation/Hero108'' is the Deer King and his men, who neigh, grunt, and whinny like horses even though deer in real life make noises more [[http://www.youtube.com/watch?v=XaPhVcLdz4M like they have kazoos stuck in their throats]] or [[http://www.youtube.com/watch?v=9EWzg4eiJnM barking.]]
* In one episode of ''WesternAnimation/JohnnyTest'', Johnny and Dukey go into their sisters' lab and take their ladybug when they run out of insects (which they used by photographing them in products and sending the pictures to the companies so they can get free stuff as an apology). Predictably, things don't go as planned as the ladybug is revealed to be highly unstable and grows into a voracious giant that threatened to eat all vegetation in its path, including an extremely rare giant pansy in Porkbelly's greenhouse exhibit. Unless it was a part of the subfamily Epilachninae (which are in fact herbivores and present a significant problem as crop pests), a majority of ladybugs (family Coccinellidae) people know are carnivorous and feed mainly on aphids. Most jarringly is that Johnny's sisters, who frequently tout themselves as geniuses, never point this out.
* Much like the Warhammer example above, ''WesternAnimation/JonnyQuestTheRealAdventures'' has an episode where Dr. Quest foinds out that Moai statues that he is studying are resonant chambers, and by playing a certain tone could speed up evolution. They discover this by testing some odd-looking grass nearby, which has triple helix DNA. Jeremiah Surd uses this in [=QuestWorld=] to ''devolve'' Race and Benton into cave men, but only their minds. How this works is never explained since their bodies don't change (since simulations don't have DNA) and there is no suggestion that it can be used in reverse. It also doesn't explain why only certain things are targeted and others aren't, even if they're in range to be affected.
* ''WesternAnimation/JusticeLeague'' has a biological inaccuracy serve as the key plot point to a season 1 episode. In "Fury", [[BigBad Arisia]] attempts to [[{{Gendercide}} wipe out all men on Earth]] with a deadly "allergen". Allergens are not contagious; different people (and different ''species'') have different allergic reactions to the same substance. And '''crystals do not make something super-allergic'''! Also, the episode focuses on the sociological implications rather than the very glaring one of "All non-magically guided humans will die off very quickly with no men to participate in the reproductive process with." Yes, the villain grew up on an island of women who are created from clay and Greek god magic, but pointing out to her that that's the ONLY place this happens might be helpful.
* ''WesternAnimation/KryptoTheSuperdog'': ComicBook/LexLuthor's pet Iguana and HarmlessVillain Ignatius often gets himself into trouble using the [[AppliedPhlebotinum Phlebotinum]] or technology of the week to catch an elusive bug or make them bigger, or in another episode, using a time machine to go to the past and try to eat a dinosaur egg. In reality iguanas are complete herbivores, as any protein is harmful to their health. Although they may accidentally eat a bug or two in the wild, they ''never'' actively hunt for anything other than leafy greens, fruits, or vegetables.
* ''WesternAnimation/TheMarvelousMisadventuresOfFlapjack'' plays with this with how medical practices were back in the day with [[NightmareFuelStationAttendant Doctor Barber]]. One infamous quote from him is, "Silly Flapjack. The human body is a complex system of pulleys and counterweights, all working to manipulate the food hole." This was probably intentional, given how the show revolves around a prepubescent sailor and his captain who uses a talking whale as a ship trying to find an island made of candy.
** In the episode where everyone catches the plague, Dr. Barber needs the uninfected Flapjack's blood to make a cure. Vaccines are actually made by studying infected blood.
* ''WesternAnimation/MyLittlePonyFriendshipIsMagic'':
** The most obvious example of this on the show is seeing the ponies in poses that would be physically impossible for actual horses, such as standing upright and crossing their legs. Less obviously, horses cannot belch, but that doesn't stop Apple Bloom from doing so adorably. They also can't throw up, but Pinkie Pie still got a VomitDiscretionShot in "Applebuck Season" after eating some bad muffins.
** Ponies frequently pick things up and do other fine manipulation tasks despite having blunt hooves. A section of the pen and paper RPG based on the show actually points this out ("No Fingers? No Problem"), and says players should just assume their characters can do things that would normally require fingers. It justifies this by saying [[RuleOfCool reality works a little better in Equestria]].
** The ponies are sometimes seen feeding ferrets with vegetables and nuts, even though ferrets are entirely carnivorous. One episode has subverted this when Fluttershy is shown feeding them fish.
** Contrary to "Winter Wrap-Up", mice, rabbits, porcupines, and tree squirrels do not hibernate.
** The bald eagle in "May the Best Pet Win!" screams like a red-tailed hawk.
** Rabbits are shown with pads on the bottom of their paws, which they lack in real life. And while most rabbits are correctly portrayed with "V"-shaped noses, others like Angel are drawn with cat noses.
** Wild beehives are commonly portrayed as resembling hornet nests.
** Parrots, toucans, and woodpeckers are portrayed with generic bird feet with three toes in front and one in back, when they should have two in front and two in back.
** Beavers are drawn with [[TypicalCartoonAnimalColors white incisors]]. Real beavers have orange incisors. Which might come off as ''even more'' cartoonish and [[RealityIsUnrealistic unrealistic]] to anyone who isn't familiar with real beavers.
** Gummy, Pinkie's alligator, has a forked tongue like a monitor lizard. He can lick his own eyes with it, which real alligators can't. He's also bright green, a color alligators don't come in.
** Ahuizotl's tiger and jaguar minions have slitted pupils, despite big cats having round pupils.
** When a pony opens their mouth especially wide, you can often see their uvula -- very few animals outside of humans have uvulas, and horses are not one of them. [[JustifiedTrope Of course, the uvula exists primarily to aid in speech, and Equestrian ponies are much more talkative than Earth ones.]]
** The seal in "May the Best Pet Win!" is more evidently a sea lion, with ear flaps and more upright posture. Although it may have been a fur seal, which do have external ears and an upright frame.
** Pelicans are drawn with oversized bill pouches.
** "[[Recap/MyLittlePonyFriendshipIsMagicS4E23InspirationManifestation Inspiration Manifestation]]": Robins make their nests out in the open and not in hollowed out trees and therefore don't use birdhouses. Robins also do not eat birdseed so would have no interest in the rather copious amount of it Fluttershy provides.
** Whenever a unicorn is shown wearing a helmet (most often Sweetie Belle), it's structured exactly like the helmets worn by other pony species. Given that the height of the horn is above the depth of the helmet layer, that kind of helmet wouldn't fit them in the first place. Also see "The Cart Before the Ponies," in which Rarity and Snips are wearing similarly constructed helmets.
** A large example is the ponies' designs in general. ''Domesticated'' horses look like that. It took thousands of years of domestication and selective breeding to get the ponies we know today. Theories of the series taking place in HumanitysWake aside, these characters supposedly live in a universe devoid of humans yet have pelt colours and flowing mane characteristic of domestic horses. If they were descended from prehistoric horses that gained sentience, they would have manes similar to a zebra, stockier bodies, dursal stripes, and striped legs similar to Przewalski's Horse or Riwoche horses. Of course, this is a pragmatic descision as the characters wouldn't be as recongnizable, or likely as cute, if they looked like primitive horses.
** While they may play this trope straight to egregious levels for the sake of the plot and settings, it's also obvious that the animators and writers have seriously [[ShownTheirWork done their homework on the subject]]. Everything from the way the ponies walk to [[GeniusBonus little things]] most people would never notice are actually done by horses in real life.
* On ''WesternAnimation/PegPlusCat'', Peg has an allergy to four-leaf clovers, which make her sneeze. This isn't biologically possible -- four-leaf clovers aren't really chemically different from regular clovers other than possibly having a different gene that causes the extra leaf to grow, but whatever allergen would still be present.
* ''WesternAnimation/PhineasAndFerb'':
** In one episode, someone pitches ideas for an "inaction figure" based on Perry the Platypus, one of which is "The Mad Marauding Marsupial of Death." Right continent, wrong order. The platypus is a monotreme, not a marsupial.[[note]]Thankfully, the creators took notice of this and have later episodes describe platypodes as monotremes.[[/note]] Ferb has also stated that the platypus is the only mammal that lays eggs; apparently, he's never heard of echidnas. Also, in one episode Phineas states that platypuses are supposed to stay inside at night. One problem, platypuses are mostly nocturnal. Perry's behavior and appearance in general is nothing like that of normal platypodes (yes, that's the plural). He doesn't have webbed hands/front feet and his tail is more like a beaver's (the platypus is covered in fur all but for their bills and feet). Overlooking all this is seemingly played for RuleOfCool, though.
** The ostriches in the show have three toes on each foot, instead of two like in real life.
** Crows are drawn with yellow bills and feet, when real crows have black bills and feet (save for the white-billed crow).
** Alligators are drawn as more closely resembling crocodiles (i.e. V-shaped snouts, lower teeth visible when mouth is closed). "Druselsteinoween" had a gator with a more correctly shaped snout, but unfortunately still has interlocking teeth. The intro of "OWCA Files", however, briefly showed gators with proper overbites, but the ones that appear later on are given crocodile-like mouths.
** "Belly of the Beast" claims sharks have molars and incisors (they do not).
** "Phineas and Ferb Save Summer" has a cave salamander that is colored more like a surface-world salamander and has fish-like gills. Real cave salamanders have feather-like gills not unlike those of young salamanders or axolotls.
** Dennis is shown to have pads on the bottom of his feet, something real rabbits do not have.
** Pelicans are drawn with oversized bill pouches and generic bird feet with only three toes.
** Maggie the Macaw in "The O.W.C.A. Files" would inconsistently have zygodactyl feet (accurate for parrots) in some scenes and ansiodactyl feet in others.
* 1973/74 ''WesternAnimation/SuperFriends'' episodes:
** "The Shamon U". A miniaturized sperm whale returns to normal size on a city street. It should be crushed by its own weight and be unable to breathe, but it's just fine.
** "The Watermen''. When the title aliens extract silicon from sea water, it causes the sea water to immediately turn into [[http://en.wikipedia.org/wiki/Red_tide red tide]]. Just one problem: red tide is caused by microorganisms, not a lack of silicon. This is lampshaded when Professor Matey notes that it should be impossible.
* A group of Decepticons from ''WesternAnimation/TheTransformers'', known as the Predacons (whom, believe it or not, are actually the ancestors of the Predacons from ''WesternAnimation/BeastWars''), actually compose of [[PantheraAwesome Razorclaw (a lion), Rampage (a tiger)]], [[FeatheredFiend Divebomb (an eagle)]], [[RhinoRampage Headstrong (a rhino)]], and [[ALoadOfBull Tantrum (a bull)]]. In real life, the alt-modes of the last two are supposed to be herbivores -- very vicious herbivores, but herbivores just the same.
* ''WesternAnimation/YinYangYo'' had at least two instances considering the like:
** In a few episodes Yin and/or Yang throw up; however, since that they're rabbits, they shouldn't be able to barf. TruthInTelevision states that rabbits are incapable of vomiting. Real rabbits lack opposable thumbs, bipedal locomotion and the ability to vocalize in English, so perhaps they possess more non-lagomorph characteristics than strictly necessary for the sake of story and audience association purposes.
** In one episode, Master Yo once suggested that he was related to raccoons, which was a popular scientific theory... once. Genetic testing conclusively proved otherwise years before the episode aired; now, it's generally accepted by zoologists that pandas are members of the bear family, even if their unusual bi-colored fur makes them the black (and white) sheep of that family.
* ''WesternAnimation/TimonAndPumbaa'':
** The episode "Cooked Goose" had the hyena trio, Shenzi, Banzai and Ed, being manipulated by a pair of cheetahs by sending them through a literal wild goose chase to prevent them from disturbing their hunts. Their first meeting has the hyenas obviously being intimidated by the cheetahs. Shenzi even puts her paw over Ed's mouth when he rudely demands what they want from them, and then immediately tries to defuse the situation with flattery, calling them "big, bold, brave cheetahs". In reality, the exact opposite would occur. Despite their speed, hyenas are much stronger than cheetahs, and since hyenas hunt in groups most encounters between the two species involve hyenas stealing prey from cheetahs. As a result, cheetahs will actively avoid hyenas as much as possible. Also, among the animals that fell prey to the cheetahs by the end of the episode are implied to be a rhino and a hippo, which cheetahs do not prey on due to large size and immense strength.
** In "Brazil Nuts", Timon called a capybara-like rodent a marmoset (a type of monkey). Clearly he might have meant a marmot, but marmots [[MisplacedWildlife do not live in Brazil or in rainforests]].
** "I Don't Bolivia" claimed that toucans have serrated bills for crushing and the antagonistic toucan character was shown crushing a snail shell. While the bill of a toucan is certainly serrated, it has weak muscles and is incapable of crushing even soft fruit.
** "Nearly Departed" implies that scorpions are insects, when they are arachnids like spiders.
** In "Once Upon a Timon", Zazu expresses disgust at the fact that Simba still eats bugs sometimes. Hornbills are also known to eat insects, so Zazu has no room to talk (hornbills also eat ''less'' pleasant things too, like snakes and lizards).
* ''WesternAnimation/TheSimpsons'':
** In "Treehouse of Horror V", Flanders ends up the ruler of the world and demands that everyone be happy and non-aggressive under his rule, or he surgically removes their frontal lobes to force them to be happy. Actually, damage (not to mention removal) of the frontal lobe would ''cause'' depression and aggressive behavior, not alleviate it.
** The part in "Bart on the Road" when Bart and co. accidentally drive through the cornfield. Depending on the school, Spring Break traditionally takes place in March or April. While it was [[RuleOfFunny a funny joke]], corn doesn't usually get that tall until early summer.
** "Cape Feare" featured electric eels that have flickering forked tongues as if they're snakes, [[MisplacedWildlife plus they're in a North American river]].
* ''Series/TheSuperMarioBrosSuperShow'' episode "Mario and the Beanstalk" features a garbanzo beanstalk covered in... pea pods. It isn't due to UnreliableIllustrator, either, since the veggies the Princess and Toad pull out from them to defeat a swarm of Hoopsters are unmistakably giant peas. Try not to think too hard about why garbanzo beans would grow into an enormous pea plant.
* On ''WesternAnimation/WildAnimalBabyExplorers'', Sammy the skunk often lets loose with a spray when upset about something. This is treated as being a minor thing at most, rather than the big stink it ought to be. Though, then again, he is an anthropomorphic talking skunk rather than a normal one...
* ''WesternAnimation/SpongeBobSquarePants'' pretty much tear the book of the biology of marine life. The most common example is [=SpongeBob=], Patrick, Squidward and Mr. Krabs having skeletons despite them being invertebrates.