LOL my high school biology teacher is really bad so I've had to watch Khan Academy to learn the entire course.
@nicholasalexander46216 жыл бұрын
It’s okay our school system is only built around money and not teaching people what they need to know. Glad to see another critical thinker
@llll-lk2mm4 жыл бұрын
@@nicholasalexander4621 same here!
@rebelgurl18200813 жыл бұрын
You made my night. You are more interesting and informative than my bio professor.. I learned more from you and did not fall asleep. I love bright colorful pictures. Thanks a bunch.
@Appledog014 ай бұрын
Thankyou so much for the video. Great explanation❤️
@cococure33927 жыл бұрын
Awesome video.
@Luvisill2 жыл бұрын
Here am I after 12 years.
@strawssurfer1312 жыл бұрын
How the hell could you dislike this?
@kipling19577 жыл бұрын
This is a why question, which I know scientists hate. But why is meiosis configured to produce 4 gametes? What is the evolutionary predicate? For example, if the germ cell was to forego DNA replication, not produce sister chromatids, but simply divide up the paternal and maternal chromosomes into two cells, your could still have 2 haploid gametes. So, why did the process evolve the way it did? I'm not asking for wild uninformed speculation. But surely some prominent evolutionary biologists must have considered this question over previous decades and come up with feasible scenarios? I just can't seem to find anything out there. Lots of "whats" and no "whys" - which is kind of boring. Show less
@ACB4876 жыл бұрын
kipling1957 Look into crossing over that occurs in prophase 1 of meiosis. This essentially mixes up the chromosomes from your mother and father, which helps to further increase genetic diversity. These mixed sister chromatids are then randomly assorted into each of 4 haploid cells. Look up crossing-over and Holliday junctions.
@suptigupta911311 жыл бұрын
cn u give d whole explaination of the full chapter?
@soupinacup Жыл бұрын
why is he talking about society and predators i just wanna finish my homework
@yazlinne509 жыл бұрын
Is this guy a genius? He knows every subject there is to know!
@daivdninjabiomech78887 жыл бұрын
no, he just reads books right before doing the lessons.
@brettbrzycki68455 жыл бұрын
Bye books you mean Wikipedia, right? @@daivdninjabiomech7888 ?
@daivdninjabiomech78885 жыл бұрын
@@brettbrzycki6845 wikipedia sucks for learning things
@brettbrzycki68455 жыл бұрын
@@daivdninjabiomech7888 yeah but he uses it... He even says it himself in another video
@reezis16195 жыл бұрын
+Brett Brzycki I seriously doubt he uses Wikipedia, in order to explain a subject as good as khan academy does you have to understand a subject profoundly yourself. His videos are so simplified even a 6 year old can understand any subject from advanced physics to biology. He takes abstract formulas / processes in physics, biology, chemistry and explains it so anyone can understand through relating the topics to every-day life things and to the foundation of the topic itself. For example, back in high school I watched his videos on circuits and he explained how every single electron interacted and how it lead to the formula Ohms Law, he even related the electrons in a circuit to water flowing and he used analogies that made it so easy to understand. My teacher just explained the formula abstractly without explaining why the formula is U=I*R. He is an insanely intelligent man, don't discredit his accomplishment by saying he copy pastes Wikipedia.
@eliudtejada98679 жыл бұрын
Who else thought his drawing of the human being was splendid? Cause I did.
@tanyachong28019 жыл бұрын
+eliud tejada Me! I was thinking the same and came into the comments to see if anyone else did:)
@eliudtejada98679 жыл бұрын
LOL great minds think alike! Tanya Morales
@pranabsaha6834 жыл бұрын
Really good 😳😳
@amberriley76339 жыл бұрын
When science finally makes sense Khan Academy Thank you so much, I never thought I would ever be able to understand this but now i feel ready for my exam.
@senthilkarpagam44603 жыл бұрын
My textbooks made no sense for some 7 long months and here goes a 20 minute video explaining almost more than what I wanted!! Kudos to you man
@katali41229 жыл бұрын
I learned more in these 18 minutes than I did in my biology class all semester. Mitosis, meiosis test tomorrow and this should definitely help. Thank you!
@savethestick86099 ай бұрын
8 years later and i’m in the exact same situation 😂 this stuff will never get old, this guys is gonna live forever through these videos
@ryn00611 жыл бұрын
wow..total "aha moment" for me. after i don't know how many times this was taught to me, it actually makes sense now. its the same information, but the way that you explain it....bravo, good sir, bravo.
@fatgoaly11 жыл бұрын
i love it, but im ocd about how if you just did two more chromosomes from your mother you would've have all 23... just TWO more chromosomes!
@esjcollins10 жыл бұрын
Great video. Nice positioning of the 'arrow' on the human!
@MS-zr8wj9 жыл бұрын
Haha
@sball9512 жыл бұрын
My mom, a doctor from back home, was amazed at how clearly Sal explained the concepts of mitosis and meiosis. Keep up the good work Sal!
@emon38512 жыл бұрын
Wow
@ChiragSonne Жыл бұрын
@@emon3851 wow
@michaelsaez7162 Жыл бұрын
@@ChiragSonne wow
@alyaziahamadalaryani740910 ай бұрын
@@michaelsaez7162wow😂
@ashamccall382110 жыл бұрын
I want to know how he learned all this...
@MonokumasSlave5 жыл бұрын
Sperm cells basically does this battle royale for the egg. remember, you were the one who got the victory royale.
@CaptainUrielVentris711 жыл бұрын
One problem I found, the first sperm does not usually fertilise the egg, the first often tires and dies (not quite so inspiring I know). The cumulus oophorus surrounding the egg requires the efforts of many sperm for one to penetrate. So in reality rather than the sprinter we are actually the sperm who finished the marathon and through using others nabbed the ultimate prize.
@Livinglifehigh15 жыл бұрын
please please dont delete these biology videos! and please make more of them!
@karlabingol53145 ай бұрын
14 years wow
@Swift326x4 ай бұрын
Z he still alive 🥺@@karlabingol5314
@TheAfricancats12 жыл бұрын
its easy but my teacher just makes it seem so darn difficult but hopefully this will help me pass my test tommorow. fingers crossed
@henrygreaves89833 жыл бұрын
how’d u go
@FlowerOFpeace114 жыл бұрын
It's amazing!! just we have to imagine how our god (Allah) is great, we were just one cell in our mothers womb!! then we became a full human with millions of cells and a complex organs systems !! just say "SUBHAN ALLAH" , the GOD who created us is very great, so we have to be MUSLIMS and obey ALLAH and worship him as he want. Because the creature should obey his creator. thank you for those benefits videos.
@dxStevenS14 жыл бұрын
No, you can't. It's always one egg and one sperm. Fraternal twins come about by having the egg split into two, and having two sperms fertilize them (therefore they are not identical). Identical twins arise from one fertilize egg (or zygote) that for some reason splits in half, which then both develop into two identical twins.
@radhhpatel10 жыл бұрын
thank you, a day before final exam!
@Linda-oc7ve5 жыл бұрын
That “I believe I am a human” didn’t sound too convincing Sal
@WantedBabe9511 жыл бұрын
wow I actually understand this, I think I'm going to cry.
@witcher47698 жыл бұрын
Hello, thanks for your videos helps a lot. It might be a stupid question, but why cant life start with just 23 chromosomes, what is the reason for having diploid number of chromosomes, since each homologous pair have similar genes that can code for a protein. So why cant an egg cell just start to divide?
@madkatt3338 жыл бұрын
Witcher47 I am not an expert but from my knowledge some species do and our cells continuously decide our body to replace old ones (think dead skin). We just reproduce needed both.
@tannerhanks53537 жыл бұрын
unless u want ur kids to look exactly like you hahaha
@sday8136 жыл бұрын
EVERYTHING MAKES SENSE NOW
@kareehudock3410 жыл бұрын
I seriously learned more in this 18 minutes then my last 7 weeks in class.. Thank you!!!
@jagadishpatil8237 жыл бұрын
very useful no need of classes
@XxAlessiaxX19 жыл бұрын
exam tomorrow:((((
@bknisha12011 жыл бұрын
started from a zaygote now im here!!!!
@NOKUT010 жыл бұрын
wheres the battlefield videos im lost
@NextGenAge8 жыл бұрын
I haven't had biology in highschool and this is so useful for my intro courses on the university. Thanks alot!
@joekeaveny445911 жыл бұрын
thank you very much for teaching more about biology in a few hours than my teacher in 4 months!!!!!!!!!!!
@khanacademy14 жыл бұрын
If they are not in a germ cell, how do they end up in the DNA of the offspring?
@ChiragSonne Жыл бұрын
Cool
@DimondAtlas11 жыл бұрын
People here 80% People that have a test tomorrow 15% People that are doing homework 5% people who are interested
@jenc96536 ай бұрын
😂😂😂
@Ree_Spec12 жыл бұрын
@HigherPlanes Yeah but by that logic, so were they.
@Swetlana015 жыл бұрын
I suddenly started to like Biology Wow keep up the good work Sal!!!
@cosmagramma11 жыл бұрын
i learned more from this than from 4 biology lessons, thank you
@dr.paddlesmack20544 жыл бұрын
holy cow, this is inspiring how well u teach
@ixlandb10 жыл бұрын
Can I just say that I love you? I hate biology!! But you make it easy to understand!
@nauleh80066 ай бұрын
watch me still fail this bio tedt
@marcadams4403 жыл бұрын
I was under the impression that gender is a social construct and sex is non binary.
@baguettegott34093 жыл бұрын
And that is true, but they're apparently simplifying stuff here.
@marcadams4403 жыл бұрын
@@baguettegott3409 Biologists love to simplify biology. Idiots
@alauc10 жыл бұрын
God blessed you, dear Sal Khan
@foziarani15313 жыл бұрын
Great awesome video,,, i swear no one could explain it like you,,,
@95TurboSol13 жыл бұрын
13:08 the arrow LOL, it is a black guy though! Sorry I couldn't resist.
@weirdzfully11 жыл бұрын
They turned into your amazinng brain
@danielterburg68815 жыл бұрын
I got a question. How can hereditary diseases be passed over to your child without mutations? Like for example, autism is a hereditary disease, but it's still caused by mutations, right?? Then how does that work?
@baguettegott34093 жыл бұрын
0:46 I hate to be THAT person, but it'd be cool if you said "sex" there instead of "gender", since it's chromosomal sex that you're discussing.
@kawsexpo2813 жыл бұрын
The capable shield happily film because garage naturalistically walk aboard a observant william. voracious, fanatical french
@YBenjamin199612 жыл бұрын
people say that the internet is harmful andthat it damages young peoples minds. This proves all those people wrong. Thank you.
@edensavril10827 жыл бұрын
Hi, you talked about 280 millions sperm in competition and 4 daughter cells. What do they have to see in common and the differences?
@SamanthaBrown201013 жыл бұрын
Thank you for making this amazing video. I learned a lot more this video than what my Bio teacher is teaching me .
@chocho15313 жыл бұрын
your mother looks very nice =]
@542pixie111 жыл бұрын
omg thankyou :) this is so mindfucking in my book
@carminecancro34882 жыл бұрын
pov day before test
@ainsalleh10 жыл бұрын
8:11 the r r r hahaa this is funny. Anyway thanks a lot!!! It helps
@ibikimorino24157 жыл бұрын
I am definitely gonna bring 💯 on tomorrow's test
@brainwise85924 жыл бұрын
Sir,it would be very kind of you , if you answer to a question of mine.Are the 4sperms or male gametes formed are in a race of fertile the female gametes or ova
@wholovessongs15962 жыл бұрын
I don't understand in school because of the kids but in this video I just understood every everything thank you so much
@TheRebekah196712 жыл бұрын
Thanks so much! This has helped me prepare for a test.
@rayan26204 жыл бұрын
I’m in grade 7 and I’m taking this help me I understand mitosis but barely understand meosis
@OpenComments15 жыл бұрын
"Approximately 1 1/2 years before I left, a new rule came out stating that if you got pregnant, you had to either get an abortion, which was heavily pushed, or leave. The rule had previously been that if you got pregnant, you had to get an abortion or be sent to a small and failing lower organization where you had to fend for yourself and your baby." - Declaration of Astra Woodcraft, ex-scientologist, former Sea Org member, and owner of exscientologykids(.)com, 24 January 2001.
@zguitarmaster10 жыл бұрын
Why isn't this video on the official Khan Academy page anymore?
@NeutralExistence11 жыл бұрын
Couldn't mutations in your body effect the way your germ cells/gametes are produced? For example a mutation of the liver, which causes it to no longer detoxify, wouldn't that end up effecting the gamete production, and possibly leading to hereditary damage? Seems like its illogical to state that there is no way it could effect your children, if one has mutations of the body, they usually effect the whole system.
@ABooleanEarth12 жыл бұрын
Germ cells are not somatic cells in that sense. So, if a mutation affects your germ cells or is the result of underlying genes in all your cells, then it will be passed on. If, however, radiation or a fault of genetic reproduction during mitosis or something causes a local mutation in your somatic cells that aren't the ones that will produce reproductive cells, the mutation won't be passed on. Does that make sense?
@Greensky0212 жыл бұрын
@TheJohannamurray Kornkornkorn (brilliant username by the way...) started off by saying that he believes in science but not in Natural Selection or Evolution. You can't selectively agree with one aspect of proven fact and not another. That's called denial. So yes, I do get heated when it comes to plain stupidity. I have no problem with religions as a whole. Go on and believe whatever you want to believe, as long as it's not hurting society. Telling everyone that evolution is silly, harms society
@rjay019513 жыл бұрын
@jeanpeup There can be a link, but it is complex and difficult to generalize about. There are many genes, and not all are equally important at all times. Life as a sperm cell and life as a human being are quite different. The gene complement that make a sperm swim fast or an egg viable may are not necessarily related to the gene complement that would make you develop normally versus a trisomic complement, or some other pathological/syndrome. In this case genes for sperm speed are selected for.
@jeanpeup13 жыл бұрын
Can the 'sperm cells race' can really be assimilated to natural selection ? What is the link between the sperm cell 'speed' and the 'quality' of the chromosomes that are inside ? I don't think there is a link at all, I think down syndrome or other chromosomal condition would not exist is ther were a link. I'm a noob in biology but this part of sal's speech bother me, can someone enlighten me ?
@Greensky0212 жыл бұрын
@TheKornkornkorn You don't have to love all mankind just because someone told you that you should. Some people truly are just assholes.You don't believe in being good for Santa Clause so that you'll get presents from him when the time comes, do you? Of course not. Because that's just silly. In this case getting into "heaven" is like expecting presents for being a good person.
@jamesusespivot12 жыл бұрын
@Brendand0n in which case weird will be wiped out however, sometimes weired is good, then it will be encourage and cherised until it is no longer weird, how else did we come about, we are very "weird" compared to other animals.
@Pinkpenguin101311 жыл бұрын
What the hell is your problem? This is a video for learning, not for criticizing other people. You have no idea who I am. Why are you picking on me? Do you have nothing better to do then sit at home and get off on being mean to other people for no reason whatsoever...
@BigMacForce11 жыл бұрын
except technically it did not have to be the first spermatocyte to the egg because it takes hundreds of sperm's enzymes (stored in the acrosome or head of the sperm) in order to breakdown the outter layer of the ovum. so instead of the fastest, it is the smartest sperm
@callummacfarlane12 жыл бұрын
While TheInvalidInput is correct, Cancer requires multiple mutations in your genes for the cells to become cancerous. So you can inherit mutated genes that predispose you to cancer but in the end these inherited genetic mutations require additional mutations for the cell to become cancerous.
@DimondAtlas11 жыл бұрын
Excuse me...I don't mean to but in...but you've lost the argument....every comment u put has been hidden due to negative reviews...his has not, as well as 2 of his comments have been top comment so I think I speak for everyone when I say: Go away :)
@evilslig12 жыл бұрын
So the sperm and egg cells consist of 23 chromosomes: 22 individual chromosomes plus 1 X or Y chromosome, but since the X and Y chromosomes consist of two chromosomes joined by a centremer - isn't that technically 24 chromosomes?
@pumbus112 жыл бұрын
no cancer cells THAT I KNOW OF, but there are some cells that are known to cause cancer or to be present in people with certain types of cancers that can be passed on, for types of ovarian cancer i think , if that makes any sense
@phoneylala9012 жыл бұрын
@cockywatchman1976 You shouldn't classify holy texts as novels. I'm not a Christian and I think what he said is absolutely ignorant. I just think that a real religion has the truth. Natural selection isn't something you choose to believe or not.
@guitarzilla15 жыл бұрын
well I suppose that would be correct assuming that said mutation would impair mobility or the ability for it to fertilize. I think that is what some of the explanation was about though and that is why I was lead to the conclusion I made.
@Pinkpenguin101311 жыл бұрын
Excuse me? I am not a loser. In fact, I do know that half of my genetic material came from my mother. Let me clarify it for you then.. the haploid I received from my father made me a winner.
@Constans69able13 жыл бұрын
@LalalusciousMacy18 i actually bough a book but my professor doesn't teach shit and you need a dictionary to understand the book. This is so much better, I'm no longer freaking out over biology class.
@guitarzilla15 жыл бұрын
sure, more cells, more chance of a mutation, but if the genetic aberration is carried by the female chromosomes, then the likely hood would be greater in the female.
@foziarani15313 жыл бұрын
Live long
@Greensky0212 жыл бұрын
@TheKornkornkorn Oh wow! You must have heard something convincing enough to ignore scientific facts! What is it? A new study? I would be curious to know!
@ZehMagster13 жыл бұрын
If your mutation doesn't affect what you pass on to your children. Then what's genetics for? I have scoliosis. My doctor says that it was from my father
@RMLLcrazy13 жыл бұрын
Sure as hell this is more than obvious... And its over explained. You repeted yourself more than 50 times. It just annoyed the hell out of me.
@Greensky0212 жыл бұрын
@TheKornkornkorn Well, in the future, for your sake, I hope you also love using your mind and questioning things. Even just a little bit!
@horse4336 жыл бұрын
The sperm race to the egg was your battle royal win. Congrats
@naveedlalkhan13 жыл бұрын
@khanacademy, i heard that X and Y fusion = male boys on and X X = female daughter? and does masturbation effect sperm count?
@MercurialSwerve11 жыл бұрын
i started watching this video thinking im going to fuck up my bio test tomorrow but god damnet this shit seems so easy thanks to you
@kreme34111 жыл бұрын
wtf man, why would you comment in the first place for a pretty obvious statement and then go on about how stupid THEY are? beats me
@werewolf778912 жыл бұрын
when he drew the little person after the cell splitting at 11: 43 it kinda reminds me of a super badass maniac from BORDERLANDS2.
@Ibahz13 жыл бұрын
I wonder if a malfunction in the sperm machinery would be correlated with a visible human mutation (down's, cri du chat, etc....)
@GokuHyperbeam6912 жыл бұрын
6:14 "...these are both EGGS-amples..."
@jpatrone9812 жыл бұрын
thanks so much i been doing good with mitois,meiosis and sexual reproduction thanks to this video thanks you help me alot.
@pareku12 жыл бұрын
i have a question about the "passing on". Is there any type of cancer that could be passed on genetically through family?