You know that Professor Dave had all the time he needed to make the video as clear as possible, right while your teacher hadn't. Also maybe the fact that your teacher explained this topic made you understand it better listening it a second time. Well it did months ago but still I don't know why the hell I wrote this when you likely aren't going to read it and it has passed so much time that you probably have 100 percent forgotten about this comment. Damm what a huge waste of time.

@@klb9672 it wouldn't had been a frustrating 🥴 note if u hadn't wasted 50% more words to explain your note as useless

Well it's not easy being a teacher,and as a student we all have to understand what hardworks they do for us.😊

I'm kinda confused 😢

Thanks prof, I can finally smile during today's lecture after I watched your video. ساره تعلمي انجليزي فضحتينا.. 😅

that was supposed to be explain

of course there is

Professor Dave Explains but still, gametes are cells with DNA inside. where this sperm and egg came from. I know they were created some where in the prostate and the ovaries. But How?

meiosis!

This topic is kind complicated, you will take it more in details in embryology. There you will understand the meiosis much better... I actually understood meiosis once i took embryology. Anyway, those 4 haploids cells produced from meiosis are the ones which form the gametes and only one of them will be used during fertilization. Meiosis has nothing to do with enhancing body parts, growing, etc.. Meiosis is just for sexual reproduction. MITOSIS is the one used to grow and enhance different body parts. A male germ cell in meiosis produce 4 spermatids(4 haploid cells) which will later mature in sperms. There are millions of sex cells in the testis that undergo meiosis and as a result there will be produced millions of sperms but only ONE sperm will fertilize the egg cell. In female egg cell is also produced by meiosis, the difference is that females will produce only ONE mature egg during meiosis. 3 out of the 4 haploids cells produced in meiosis will degenerate thus forming only a SINGLE egg cell. Again,this is how gametes are produced. As i said, when you take embryology; spermatogenesis and ovogenesis you will get the point. *For now, if you still haven't taken embryology, you can just know that MEIOSIS PRODUCES GAMETE CELLS*

A whole zoology playlist is coming soon!

@@ProfessorDaveExplains thank you so much. It was very helpful 😄💜

well it's not that four haploid cells generate a zygote, it's simply that meiosis produces four haploid gametes, in both males and females, so one somatic cell will make either four sperm cells or four egg cells. then, totally separately, a sperm cell and an egg cell fuse to become a diploid zygote, because n + n = 2n.

@@ProfessorDaveExplains can u please make a video to explain. Like zygote is formed with 46 chromosomes 23 from each parent. Then after fertilization meiosis takes palce? 😭😭😭😫😫😫 i am sooo confused.

No, after fertilization mitosis takes places. Meiosis forms the gametes.

The cells undergoing meiosis have both sets of chromosomes, they must be separated in meiosis 1.

Well, humans are animals, so humans would of course have animal cells. Unless you heard somewhere that centrioles are absent in humans... Did you hear that somewhere? It's been a while since I learned this in school.

Me tooo please help

I'm not an expert but as i know, the homologous chromosomes(paternal and maternal) that undergo crossing over when producing sperm or eggs(during meiosis 1) are the chromosomes which were passed by their own parents. There are 23 pairs of chromosomes( 46 total, 23 paternal and 23 maternal) in every cell of the body Let's say someone produces a gamete. During profase 1 'paternal' and 'maternal' chromosomes(homologous) swap a section of DNA, these maternal and paternal chromosomes actually belong to the parents of the person producing the gamete.

"He knows a lot about the science stuff, Professor Dave Explains!"

Hi

@@ProfessorDaveExplains lol

the sister chromatids are identical, so when they are pulled apart it's still the same number of chromosomes, just now unduplicated

@@ProfessorDaveExplains That's what I was thinking, thank you!

23 pairs of chromosomes so 46 chromosomes at all times, which can either be unduplicated or duplicate sister chromatids in the familiar X shape.

Zahraa Al musawi im glad to see another Iraqi here, keep up your leaning journey

🌹🌹🌹

Cheers to Iraq from Chile. Wished id visit some time!

The gametes undergo fertilization and the zygote is diploid. The rest is mitosis. This is all explained very clearly.

The zygote is already diploid, it divides by mitosis.

Heh. Now I finally got it.. Meiosis happens later (before birth or during pubertity) and it Have nothing to do with fertillization.. I always thought fertillization process includes meiosis somehow 😅

@@wepe187 lol.. this was the same doubt puzzling me for years. NOw its clear. ha ha

one day definitely!

no no, meiosis is what produces the egg and sperm. once the zygote forms, it only undergoes mitosis.

the gametes undergo fertilization

In simple terms; father makes 4 cells, each is called a gamete (haploid), mother makes 4 cells each a gamete also. Then one gamete from each parent join together to form a zygote which is, therefore, diploid. The remaining gametes just die off and the zygote will continue to grow by mitosis. haha.

I don't think so. Meiosis occurs in the ovaries and testis, and people with Swyer syndrome don't have either. From my understanding, Swyer is when the Y chromosome screws up and doesn't turn someone male due to a defective or missing SRY gene. I may be wrong but I remember learning in high school that meiosis occurs in the ovaries (to produce eggs in females) and the testis (to produce sperm in males), so you need either of those organs to do meiosis and make gametes.

And what about It?

No,matured RBC donot have nucleus..so it has no dna

No, they are haploid. The homologous chromosomes were separated.

@@ProfessorDaveExplains what about the tetrad? In meiosis 1 there will be 92 so at the end there is 64 again and then when they separate at the end of meiosis 2 there will be 32 in each

well i can't change the clip in any way, but just watch it again and/or pause when you want to stare at something!

Professor Dave Explains OK sir thank you

Click the wheel on the bottom right side of the video. There you can set the speed of the video. Put it on .75 It'll help

i don't know what you're referring to

sure, that's correct

watch one more time!

I think it takes in material from the outside first and uses it to duplicate. So it literally doubles its mass before returning to normal size... I think... I'm not an expert in this field by any means, but that's what I remember.

the compounds inside the food we eat are broken down into smaller components, and those components are then used to create/regenerate cells by turning into proteins, sugars, fats.

😂😂😂😂