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- Опубликовано: 9 ноя 2021
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#meiosis #CellDivision #biology
SCIENCE ANIMATION TRANSCRIPT: In this lesson, we'll explore the details of what happens during the phases of meiosis. Meiosis, sometimes called reduction division, is the type of cell division that produces gametes. By gametes, we mean sex cells such as sperm cells in males and egg cells in females. Meiosis is broken down into two stages of cell division called meiosis I and meiosis II. Meiosis I has four phases: prophase I, metaphase I, anaphase I, and telophase I. And meiosis II also has four phases: prophase II, metaphase II, anaphase II, and telophase II. Let's look at what happens during meiosis I. Prophase I starts with a diploid cell. Its chromatin contains two uncoiled, spread out sets of chromosomes, one from each parent. After the DNA in the chromatin replicates, it condenses into the more familiar X-shaped chromosomes. The replicated DNA is the same in the identical sister chromatids of each chromosome. In a process called synapsis, each chromosome pairs up with and binds to its corresponding homologous chromosome, forming a tetrad. A tetrad is the group of four sister chromatids in paired homologous chromosomes. The chromosomes contain genetic information called genes. These genes were inherited from each parent, and different versions of the same gene on each chromosome are called alleles. In a process called crossing over, chromatids from each homologous chromosome exchange segments of alleles. Also called recombination, crossing over randomly happens on every chromosome, resulting in different gene combinations. This explains why every gamete is genetically different from every other gamete. Crossing over results in genetic variety in offspring. This is why children are different from their biological parents, as well as from their biological siblings. Continuing on with prophase I, the nuclear membrane disappears, the centrioles move to opposite ends of the cell, and spindle fibers fan out from them. Next, in metaphase I, the homologous chromosomes line up at the equator and attach to spindle fibers from opposite poles. During anaphase I, spindle fibers separate the homologous chromosomes in each tetrad and pull them to opposite poles of the cell. The cell enters telophase I with one chromosome from each homologous pair at separate poles. However, each chromosome still consists of sister chromatids. Keep in mind that each chromosome's sister chromatids are no longer identical because of the allele exchange that happened during crossing over. Then spindle fibers disappear and the nuclear membrane re-forms around the chromosomes. Finally, cytokinesis occurs. Meiosis I ends with two genetically different haploid daughter cells. Each haploid cell contains only one set of chromosomes consisting of paired sister chromatids. Both cells now enter the next stage, meiosis II. However, unlike meiosis I, DNA does not replicate before meiosis II begins. Once again, in prophase II, the nuclear membrane disappears, and spindle fibers fan out from the two sets of paired centrioles. During metaphase II, the chromosomes in each cell line up at the equator and attach to spindle fibers from both poles. During anaphase II, the sister chromatids of each chromosome separate and move to opposite poles. Once the sister chromatids separate, they are called chromosomes. Finally, during telophase II, the spindle fibers disappear, and nuclear membranes re-form, and cytokinesis occurs in both cells. Meiosis II ends with four genetically different haploid daughter cells, each containing only one set of chromosomes. Some key points to remember about meiosis. It begins with a diploid cell. Meiosis only produces gametes. Gametes are genetically different haploid cells, sperm cells in males and eggs in females. Meiosis has two stages of cell division called meiosis I and meiosis II. During meiosis I, homologous chromosomes separate to produce two haploid cells, each containing chromosomes in the form of paired sister chromatids. In meiosis II, the sister chromatids separate in both cells, becoming individual chromosomes. Cytokinesis of these cells produces four genetically different haploid gametes. And here are some key points to remember about prophase I. The pairing of homologous chromosomes called synapsis occurs. Each pair of homologous chromosomes, consisting of four chromatids, is called a tetrad. During the process of crossing over, chromosomes in homologous pairs exchange segments of alleles. Crossing over results in genetic differences in gametes. All gametes produced by meiosis are haploid. [music]
NSV16019
even though I have learnt this a million times, im still absolutely mindblown every time I watch these videos, beautifully done, OUR BODIES ARE INCREDIBLEEEEE
Indeed!
RIGHTT!!?!
Indeed allah is the best creator
@@aymensuduzoi4916 absolutelyyy how wittingly He swt made that simple crossing over to be the basis of all sorts of variations in human beings, in a way that every single person is unique! blows my mind subhanallah
@@aymensuduzoi4916 Not Allah, but the Great Creator of all, who has never spoken to anyone, who never speaks to anyone, and who will never speak to anyone. The one who created life for everyone on this planet, but because he never spoke, he never promised any life or existence or anything for your soul after you die. He never actually needed to create any soul to let you exist, so he doesn't keep this imaginary item after you die because the item never existed.
This is the BEST video I have found on meiosis. All of the important details were included and for being a relatively short animation, it really did the process justice. Thank you so much!!!
i agree , very helpful video :)
Hi...r u a university student...?
so true
yes, you are right
yeah i was abt to say that
Who is here from india..
What is your nationality
Why are u from Pakistan
Any problem
@@subhamitdeb6824really bro you don’t see her flag
Free Palestine
Mexican 😂😂
stages of prophase 1
01:00 leplotene
01:20 zygotene
01:40 pachytene
diplotene unclear
2:40 diakinesis
Im not sure that right
Leptotene*
Diplotene and diakinesis
Tq
Plis in spanish
This is much better than my teacher's lecture of an hour and a half, keep it up and thank you very much
Right bro. Same here
Agree
Wow😊😊😊😊😊🎉🎉😂😂😢😮
ruclips.net/video/LiJnICs2CaQ/видео.html
Yes
أفضل طريقة لفهم عملية الأنقسام من خلال هذا الفديو التوضيحي ، شكراً لك❤
1:33 synaptonomal complex leptotene
1:39 zygotene tetrad formation
2:05 pachytene crossing over
2:45 diplotene synaptonomal complex disappear
2:57 diakinesis chiasmata ends
why u gotta write it liek a nerd
Bro it,s wrong
@@alonerager5960 no
@@S.karthikeyan12th yah it is formed on zygotene my bad 😅
thank you bro 😅 this is known as focus 😅😅😏
A Yakeenian here after Tarun sir showed this animation !
Yes😂...from yakeen 2
Mai ye comment krne aai thi yrr.....😅😅😁😂😉👏🙏🏻
Bhai kal class kitne baje hai... tarun sir kaa
Me also 🤣
@@falgunidehuri2256 kal to sunday haina vai
Thanks form Algeria 🇩🇿 😊
sometimes an animation helps like crazy but the slow, clear explnation ensures that anyone can watch this video and understand this pretty well. You're amazing and thank you
I've been watching Nucleus Media and Nucleus media to broaden my understanding for 5 years now. I can't express how thankful I am to have access to these video it really helped me visualize and understand it in-depth.
Thanks for watching!
This explanation is trillion times better than my school teacher lecture
Thanks sir ❤
If you explain leptotene,zygotene, pachytene, diplotene, diakinesis of prophase 1 separately would be more helpful
By the way it was very good and the presentation was fantastic!love it
yeah bro..i was also gonna comment the same..I am preparing for my medical entrance exam..so I needed that..!
@@rohitnayak4096 that sounds great to me Cause I'm also preparing myself for medical entrance 😀
@@tasfin9905 So am I hahaha. Goodluck guys
@@rohitnayak4096 so am i
dude theres more wtf no thanks
This is the best channel for medical students like me ❤️❤️❤️❤️ Thank you so much Sir.
👍
Main yakeen me hu
@@sakshamchoudhary9203 toh ?
@@sakshamchoudhary9203 kisine pucha ?
This was a new topic for me to learn and this video left me with no confusions 😳. Mindblowing animations please keep uploading such videos 😄.
This is hands down the easiest explanation i have ever heard. Keep the good work up, I absolutely, love your videos
شكرًا لك على هذا التوضيح
لدي إمتحان في آخر الشهر وهذا جزء من الموضوع
أنا متأكده أنني لن انسى هذا الكاركتر اللطيف والصوت الواضح
عندما أدخل في الجامعة التي اريدها سأدعو لك كثيرًا ❤️
اعتقد بس اني هنا طالب سادس😍😍
انشاء الله نكمل السادس بنتيجه حلوه🤗
Just 89k likes with millions of views for such incredible explaination!? THIS IS UNFAIR YOU DESERVE SOO MUCH RECOGNITION!!!! ❤❤
هذا الانقسام الاختزالي
طلاب السادس شلونكم ✌🏻✨️
One of the best videos on the topic I've watched. Great explanation. Thank you.
Thankyou soo much for these animation videos They are really very helpful ❤❤
This topic used to be hard, for me 😢but now it's history ... thank you so much sir, you are a great teacher 🎉🎉🎉
Was struggling with this for a long long time. Glad I stumbled across this video, thank you for help!
ruclips.net/video/beQbCOuRQos/видео.html
This was incredibly helpful in visualizing all of these key points. Thank you so much.
ruclips.net/video/beQbCOuRQos/видео.html
This is by far the most educational videos I have ever watched. Keep posting guys and I appreciate the effort. P.S. If you could guys make videos about BIOMOLECULES, it would make my day.
agreed!
I'm a spanish speaker and I understand this video so well, it's really amazing how you explained all this, congratulations 💗
Thankyou so much✨💕
Your explanations are very helpful and the animation is easy to understand
And the narrator voice is so soothing and calming, it helps me to understand the video
The best examination of my life I saw today, keep posting, the world needs you.
This is hands down the clearest video I've found on meiosis
I'm having my biology exam tomorrow. This video explains everything so well. Thank you so much 😊
How did it go?? Mine is on Tuesday. 😬
Same
Better than my prof
I agree 😂
Wonderful demonstration and explanation! What more a bio student wants!
Finally, after many Uni level classes, I understand! They always skip so much important details! Thank you!
Meiosis was one of my toughest topics to understand but now it easier for me after watching this video 👍
What a beautiful biological sciences, especially in cytogenetics. Thanks for the brief explanation.
For neet it is most important ❤
After reading NCERT it is going on so smooth 😊 understanding...
Oh my God, the best explanation has been shortened to hours-long lectures. Thank you very much ♥️✨🥹
Glad it was helpful!
I think this is the simplest most comprehensive and helpful video I've watched on the topic!
My head lost from video to another and I can't understand, but when I come to this video I became very happy to share it with my friends 🧡
I'm in first year of high school and this is what we are learning! Thank you! I finally understand biology
11th class?
Same , I am in 9th and this video helped me alot !
@@dhruvupadhyay8757
Yes dear ❤😊
The 3D animations are absolutely vital to understanding this properly. Looking at them on a slide under a microscope did next to nothing by comparison
دكتوره دلال جزاها الله كل خير شرحتلنا على هذا الفديو ❤
This is the best video literally thank u so much for clearing a big problem for me u explained it so easily 👏
Meiosis is a sexual reproduction. 2 Types of reproduction system is there sexual, asexual. Sexual happens when the gametes are being fertilized and asexual happens when there is no gametes nor fertilization. Meiosis are haploid, where one set of chromosome. Meiosis have 4 daughter cells that are not identical to mother cell.
Your work is so good that even the nonbio students get addicted to it .😊
Thank you. You gave clarity for me about mieosis
May God bless you sir. And continue with the spirit of helping us. You are helping us alot.
Sir, thank you so much for these videos! They're very educational. I'm so grateful and honored to be able to watch these videos for free. God bless you kind sir and more success to come to your channel!
Amazing! you made it very simple to understand even though I have no knowledge of biology. Thanks!
Now I understand why meiosis produces 4 cells and not two. It was wonderful! 👌
'''Once the sister chromatid separated they are called chrosomes '' - you just cleared my all confusions in no time. Thanks for the explaination
Incredible explanation and animation ❤️
This was really helpful during my exams, thank you so much :)
this video deserves much more likes !!! great explanation and animation
I had already taken a lecture on this, from school but after watching this I got the answers of my questions... So please keep uploading these type of vedios (jazak Allah)
Я в шоке, тут все настолько просто сказано, что я со своим уровнем английского поняла каждую часть!!! Спасибо большое за это видео!
Thanks for this video!
Those who don't know English will soon become extinct like dinosaurs 🤣
@@aloksharma12124u actually, many people don't know English. For example I'm very bad know this language
@@aloksharma12124u amm no, everyone has their own mother tongue, their own language and the languages that they know like I know Urdu Hindi English Sanskrit, but if I didn't know English very well, it wouldn't be hard for me to survive as there are many people who just know their mother tongue or their national language or their regional language.
Excellent video! As a neet aspirant this was very very very helpful!
i thought my entire life that studying anything would be extremely boring until i watched this video, much appreciated
Tarun sir op
It is very good explanation sir excellent 🎉
thanks help study for my biology test today
I have tried learning this from various textbooks & lectures and I simply have not understood the phases / differences etc. Everyone explains it in SO DIFFICULT way. This is the first time understood it, and seems like it isn’t that hard at all. THANK. YOU.
man !! thanks to you I am gonna pass now😂😂
I love these videos !
straight to the point and organized
love it
Wow thanks sir, I just understood meiosis clearly after so many years of trying to get the understanding. I will recommend this video to my colleague students.
I always look for animated videos of any topic i read , and i end up watching nucleus RUclips channel ,i have been watching these videos from 9 th standard and now I'm in class 12 th ,and i dream to be a doctor and kinda this channel has ignited the love for biology in ne , I'm so grateful for this channel.❤️
never give up on ur dream, if you continue to never give up your bound to acheive it! good luck
هسه اني سادس بس فهمت على الشرح ❤😂
this 6:31 sec video cleared my concept so much that an entire lecture couldn't......................thanks a lot @Nucleus Biology
This is the best educational biological video I’ve ever watched
You’re the best
شكرا جزيلا كان الشرح رائع 👍
Mano mto bom e ainda tem legenda pra português
Finals for university is stressful but this video clearly made me relieved of what Im doing cause Ive learned this in my highschool years but it keeps going for no reason.
I think this Channel would be helpful for me in cracking NEET
Thanks a lot Team Nucleus
thnx for such a beautiful videos
Wonderful! I was able to understand this process better with the video! Thank you! ^^
Gran Profesor MODERNO, que explica temas complicados y los hace entendible. Felicitaciones
Hey there!
Thanks a bunch!!
I loved the way you explained
That was so understandable🤩
Sir you should have elaborated Prophase - I
it contains leptotene , zygotene , pachytene , diplotene and diakinesis phase too
But it was a great video 👌
Hope this type of animations we get to see in our school classes.
Best video for understanding meiosis 😊 thanks 👍
Who is come here after yakeen 2.0 pw?
Are you pw student?
@@ManishKumar-om6el yess
@@pragatiyadav7291 nice👏
Me 😅
Bhery gud inglis 😮😢
Estoy aprendiendo inglés , y no hoy mejor forma para mí que practicar este idioma viendo vídeos de biología en inglés. Muchas gracias amigo :D
أتفهم ما يقولة باللغة الإنجليزية؟
Amazing this is the best for me to revise the whole chap in minutes as tomorrow is my test and this is the video( fr )👏👏👏
Finally a video that makes sense. Thank youuuu❤️🙏🏻🙏🏻
I'm a pharmacy student and it was so difficult to understand by reading, but this is awesome. Thank you for this wonderful animation.
Is it hard to study pharmacy?
Excellent
Thank u so much sir...i used to have doubt in meiosis.....now i understood why meiosis is Known to be four identical daughter cells
I'm preparing for neet and this helped me a lot
Finally, I understand homologous chromosomes 😍😍😍
If it's haploid why it has 4 arms
haploid consists of 23 cromosoms . diploid have 46 cromosoms
@@elenavasaiu2090*chromosome 💗
This vid is very thorough and very very understandable.
Thanks for brushing up my biology
Any Pwian
A mistake, after meiosis I the resultant cells are generally different diploid cells not haploid
Meiosis I ends with haploid cells. Meiosis II is a mitotic division of each of the haploid cells produced in meiosis I.
It's haploid coz you have 23 duplicated chromosomes. Count the centromeres (23) and not the chromatids (46)
You have no idea how useful this video was for me
Great explanation and wonderful animation.
Thanks sir ❤
Who is here from Ethiopia😊
Means
Me❤
Me but which region are you
I am india