Phases of Meiosis
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- Опубліковано 29 вер 2024
- In this video Paul Andersen explains the major phases of meiosis including: interphase, prophase I, metaphase I, anaphase I, telophase I, cytokinesis, interphase II, metaphase II, anaphase II, and telophase II. He explains how variation is created in the next generation through meiosis and sexual reproduction.
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Title: String Theory
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All of the images are licensed under creative commons and public domain licensing:
File:Karyotype Color Chromosomes White Background.png, n.d. commons.wikimed....
File:Mars-Male-Symbol-Pseudo-3D-Blue.svg, n.d.
"File:Sky Spectral Karyotype.png." Wikipedia, the Free Encyclopedia. Accessed March 7, 2014. en.wikipedia.or....
File:Venus-Female-Symbol-Pseudo-3D-Pink.svg, n.d. commons.wikimed....
ScienceGenetics. Español: Espermatozoide Fecunadno a Óvulo., June 25, 2010. Own work. commons.wikimed....
Unknown. English: A Sperm Cell Fertilizing an Egg Cell, [object HTMLTableCellElement]. www.pdimages.co.... commons.wikimed....
This is the man that's been there for me when no one has. Thank god for his existence or else I wouldn't be able to maintain an A in biology.
What are u doing these days
@William Greenwood well well well, if it isn't the father of Zachary Greenwood
@@mastersword6470 whos zachary greenwood
🙏
I was the 1000th like. I feel special.
A literal god among men. A being of pure science has descended to the earth in order to spread his knowledge so even a numskull like me can understand him perfectly and actually remember the lesson.
No but literally this demonstration was more helpful than 2 weeks worth of biology classes. Thank you so much everything makes much more sense now :)
Awesome video! It's by far the best I've come across. Thank you lots and lots for making these videos for us...it's much appreciated :)
You just saved my life!! I can't be more thankful to you..
You save my life! I've Bio test tomorrow and this's a lot better than just read notes! XD
Best ever expalanation I had.
You make the best videos! Thank you!
Very good video. Brilliantly explained. Can I add one thing though? Whilst recombination events are important for different species as a whole, via essentially mixing variants into new chromosomal combinations, natural selection works at the level of the individual organism, so it is wrong to assume that this process evolved to function as a "variant mixer". Recombination is a process which aids in double strand break repair of DNA strands, and it is this function which most likely explains its existence at all.
Thank you! I really appreciate these videos. I sometimes get stuck in the text and have difficulty visualizing it on my own.
extremely helpful should get an A on my meiosis esssy
Thankyou so much sir , you are an amazing teacher .
#savedMyLife
scored 90% in biology because of you.
and yes That was helpful :)
If we had bio teachers like this in college, all the students would be scientists after the first quarter of general biology!
It helps me a lot, thanks dude! For real! Go on with more videos like this!
Honestly, you should just be my professor for everything.
Your videos are AMAZING!
Great vid and great commentary.
What did you mean by "multiply it by 13?"
Fraser Cameron I have the exact same question!
@@eldrienadsilva3385 , what time
Awesome! Thank you so much, I finally understand it!
It was a little helpful. I wish I could grasp it. Agh. Why do I find this so confusing?
chromoZome
woah thanks so much , all my teacher did was read the PowerPoint
thanks alot this was really helpful
It's like teachers try to hide how easy it is to learn this stuff instead they do like 2 weeks of lecturing and after watching this I've learned more
icy knight lol my teacher is great
ROFL it does seem like that sometimes.
I think the real problem comes down to pace. Everyone works at a different pace and unfortunately when learning in a classroom or lecture you can't. So as soon as you don't understand something, you can't rewind a video or pause it, you have to try and catch up and so then everything spirals out of control and you end up learning bits of pieces of the lecture but not being able to understand anything fully. I spent a good 8 - 12 min on this meiosis video (after first learning mitosis), went at my own pace, and I understand everything. WE ALL WORK AT DIFFERENT PACES
I think the real problem comes down to pace. Everyone works at a different pace and unfortunately when learning in a classroom or lecture you can't. So as soon as you don't understand something, you can't rewind a video or pause it, you have to try and catch up and so then everything spirals out of control and you end up learning bits of pieces of the lecture but not being able to understand anything fully. I spent a good 8 - 12 min on this meiosis video (after first learning mitosis), went at my own pace, and I understand everything. WE ALL WORK AT DIFFERENT PACES
@@EvsPersonal K.
Chromosomes: 0:52-1:51
Centrosomes: 1:52-2:12
Interphase I: 2:12-3:02
Prophase I: 3:02-3:58
Metaphase I: 3:58-5:35
Anaphase I: 5:35-5:41
Telophase I: 5:41-5:46
Cytokinesis and overview of meiosis I: 5:46-6:04
Prophase II: 6:04-6:11
Metaphase II: 6:11-6:19
Anaphase II: 6:19-6:24
Telophase II and cytokinesis: 6:24-6:32
Overview of meiosis and before/after comparison: 6:32-6:46
Review of phases with diagram: 7:22-8:11
Level 100 boss
Bio freak
u r a legend thank you
I hope you're doing okay! my hero...
My hero
You make my life like 7 million times easier than it would be. I was absent and missed my bio lecture. I have a quiz tomorrow and thanks to you I'm going to get an A.
Advaita Naik I'm happy to hear that the video was helpful. Your life must be pretty easy now that it is 7 million times easier. :)
Bozeman Science same here. i have a test and a presentation on the hole dna synthesis both on the mitosis and meiosis. u made my life less miserable. i bow and take off my hat for u sir...
Really..
I have two quizzes tomorrow and I finally get it! Visually seeing it and talking me through is awesome! I want to be a marine veterinarian, so I have to know this information!
+fabulous fallow up! passed the test, tore apart biology like it was nothing , and now i am a medical student.
Hank green + John green = this guy
was thinking exactly the same thing man
that's meiosis
Qais Jan lol
Greens - fluff = Paul Andersen
+ Laci Green
I love you dad
gayyyyyyyyyyyyyyyyyyyyyyyyyyyy
Connor McNamara lol
u mean daddy?
I love you too son
Dr. Krab 😂
omg i cannot even begin to express my gratitude for you making these lessons available on youtube, thank you so much! you make it seem like doing bio as a major isn't too difficult, which unfortunately, is not the case
My bio exam is tomorrow, why didn't anyone tell me about this guy before D:
U probably smell bad
in my ap bio class we use these video as hw & do notes & summaries on them, they help a lot !!!
Kris Kringle lol i laughed so hard i almost got in trouble... I was supposed to be working
3 years later and im asking did u ever pass ur bio exam?
because u started studying 1 day before exam like me and it is the first time u r watching bio videos like me.. i am also here 1 day before exam
Wish u were my bio teacher
Suddenly life makes sense
Mr Anderson's ability to demonstrate and explain all the scientific / biological processes terms is so superb. He does it so well and it just sticks with you no matter how hard the material seems, Mr. Anderson makes everything seem learn-able!! Thank you so much for your amazing help and videos!
thank you so much now I can finally teach my balls how to function properly.
HAHAHAHAHAHH
so true its for nothing hahahaha:D
fucking high school why need i know this shit!?:
my bio teacher just shows us these
can this guy by my teacher for every subject! he explains things so well!!!!!!
Not me studying last minute for a test i have during covid
Same 😬😬
Mr. Anderson has no idea how much he's helped me in passing this horrible biology class. THANK YOU
You explained it much better than my professor. Thank you!
I have literally watched about 15 videos on meiosis and this is hands down, the best explanation there is. Great visuals and a thorough explanation of the process.
You're my hero. You're literally helping me through the MCAT more than my $400 set of books are. Wish I found you earlier
I believe one of the many reasons why these videos are so helpful is because when you watch these, you aren't in the classroom environment, and therefore you're actually focused on the teacher rather than any distractions! nevertheless, great video! thank you for making my AS level that much easier!!
whats a meiosis in a cats body - meowsis
+Donald Duak what do you call when lots cats stack together-- meowtain
fat
burn in hell
You made me laugh so hard I stubbed mitosis
Donald Duak year of the joke😂😂😂
So much better at explaining it than my professor! Thank you so much! 🙌🏽
FINALLY someone who actually makes sense! i went into this knowing that it was easy but for some reason could not get it in my head right. Thank you for finally clearing this up!
Not my proudest fap
omfg
I just died😂😂😂
SYDNEY FIELDS that would be a fucking smart child to understand AP bio😂
you're an over salted pretzel
wtf r u ok?
I didn't do A-level biology, now I'm studying Medicine. This has REALLY helped, so thank you!
Are u done with medicine
Wowwwww!!!!!! Thank you sooo much for all the amazing information. You’re helping me sooo much, so genuinely thank you. May God bless you and your family🙏❤️!
Mr Anderson, Your students are extremely lucky to have a teacher able to articulate advanced concepts in an easy to understand way. Your videos have taught me more than my actual professor has. Your students are AP and get college credit, right? I'm in 2 college bio classes (my uni splits it into separate classes for all science majors) and without your help, studying would be extremely tedious! I can only imagine the number of people who would not have been successful without your videos. Just by your view counts, I can tell that you are making a HUGE difference in student's success at a (probably) global level. That's awesome! You're the best!!
Biology AS level students where you at?
ItsMichaelAkin A2 now 🎉🎉🎉🎉
here my man
@its me Haha I'm in 3rd year of uni now. All the best to you! Biology is a great subject
Ngl this is the video that just helped meiosis click for me, 10/10
how many chromosomes are there at the start of meiosis? If there's 23 chromosomes in each of the 4 daughter cells then I'm guessing 92 after interphase?
my professor explained it better....just kidding.
Took my professor 2 hours to explain meiosis, when you did it in 8 minutes. I have a better understanding of it after watching your video, than when my prof. taught it.
You forgot to say something pretty important. They became 4 hapliod cells
Can an X chromosome form homologous pair with y chromosome (of a male's cell)? Can crossing over occur between X and Y chromosomes of a cell in meiosis-1? If yes, how to decide/identify which of the resulting 4 chromosomes in meiosis-2 is an X or a Y chromosome?
Anirban, the cells become haploid when the Meiosis I ends. As he said on the video, the homologous chromosomes are separated (the quantity of chromosomes is split in half), because they were duplicated during the S phase of Interphase, not the sister chromatids as happens on mitosis. Following Meiosis I, obviouslly there is Meiosis II and this division is Equational, because they maintain the same chromosome number. Hope you got it.
Can an X chromosome form homologous pair with y chromosome (of a male's cell)? Can crossing over occur between X and Y chromosomes of a cell in meiosis-1? If yes, how to decide/identify which of the resulting 4 chromosomes in meiosis-2 is an X or a Y chromosome?
of course it was helpful)thank u very much!
Hi Mr. Anderson, can you create resources like test materials that would ease high school students and relieve their stress? If you can publish them, that would be an extremely helpful support, especially, for those who have impeding health issues. Thank you!
Very nice explanation, enjoyed this thoroughly
thank you so much you explained this so much better than the Discovery Techbook!!!
steven magaling owo veron is Bow²
Baklaaa
I spent 2 hrs of class not understanding a thing and now i can tell metaphase 1 from 2 by just studying for 8 mins. Wow.
lol you saved my genetics test thanks to you!!
i have a biology test on wed on meiosis! perfect timing!!
Just no one explains it better that you do. Thanks please
Literally just watching these is helping me so much for my ap bio midterm, thanks!!!
Thank you, "Bozeman Science" and all the UA-cam users for your informative comments. I learned a lot from you all. Now I have a request: Please verify if the following understanding of mine is correct, and also please help me find an answer to my question at the end.
My Understanding:
================
One Chromosome contains exactly one DNA molecule (I am ignoring non-DNA parts of the chromosome for simplicity)
Typically, in a human somatic cell there are 46 such molecules. (I used typically because Wikipedia says some cells, under some conditions may contain more. Search 'endoreplication')
These 46 separate molecules can be sorted/arranged into 23 pairs of molecules. Each pair consists two nearly identical molecules, one obtained from each parent. Each molecule in the pair is a physically independent, standalone, structure -- not joined together in any way. The normal X shaped diagrams that we come across are that of an intermediate state during which each DNA molecule is replicated -- holding 2 molecules per chromosome temporarily. Later on these are pulled apart and separated as the cell divides.
When the cell is growing, the DNA molecules are not condensed into chromosomes, but are present as chromatin fibers floating around in the nucleus. That is, each chromosome pair will unwind, and leave two nearly identical chromatin strands in the nucleus.
These chromatin strands are used by ribosomes to decode instructions, which eventually results in chaining together of different amino acids to build molecular structures called proteins or enzymes.
My Question:
==============
If my narrative above is correct, my confusion is which of the two nearly identical DNA strands floating around will be read for making a particular protein or enzyme? Since two strands are available for reading, I am confused how the cell picks between the two. Should Mom's instructions be followed or Dad's instructions? Or read both and then choose? Can some one please explain this or direct me to URLs that may help my understanding?
Thank you all in advance.
You're such a big help Mr Andersen, thank you for being so concise and simplifying things!
sorry but I think u made a mistake in minute 3:10 because u r talking about mom and dad and actually this process occurs before fertilisation ! nevertheless it is great :)
regards,
+Ahmed Zainy He didn't make any mistake, each of us have a chromosome from dad and one from mom, that are making a pair :) So when sperm or ovules are created, the chromosome from mom and the one from dad are getting mixed for the sake of variety.
why did i watch this even though i understand meiosis?
Can an X chromosome form homologous pair with y chromosome (of a male's cell)? Can crossing over occur between X and Y chromosomes of a cell in meiosis-1? If yes, how to decide/identify which of the resulting 4 chromosomes in meiosis-2 is an X or a Y chromosome?
Why are there 4 chromosomes (so 8 chromatides) in the beginning?
You just had one chromatide from your mother and one from your father, so 2 non-identical chromatides. Wich then makes copies of it self -> 2 chromosomes (or 4 chromatides)
Please HELP ME, im going CRAZY!!!
Thank you so much! My midterm is on Monday and we just finished learning this chapter on Wednesday so I've been panic cramming and this is the only video that's explained things clearly. You are a life savor!
very nicely explained.. towards the end you said that in case of egg only one of these cells undergoes fertilization (out of the 4 ).. why is that so?also you have shown only ch no. 1 and 2.. but there will be 23 total chromosomes in the egg/ sperm right?..so during fertilization , will all the 23 combine with the other 23 from the dad/mom?
it is very helpful. It will be very helpful for my tomorrow's exam
Sheldon Cooper is kept awake at night knowing that his intellectual superior, Paul Anderson, is out there teaching science better than Sheldon can even imagine.
I'm on Team Paul.
He has such a clear way of explaining things sooo simply
When are the chromosomes getting haploid?
In mitosis the chromatids where separated and they remained diploid...here...there is crossing over.. But finally the chromatids are separated...so when exactly is the cell getting haploid?
After meiosis II. The difference is that the DNA isn't replicated during this phase, so in mitosis you actually end up with 92 chromosomes after S phase, then they are split into 46 for each diploid cell. During meiosis two the 46 chromosomes in each diploid cell that is produced by meiosis I are split at the centromeres producing 23 chromosomes for each haploid.
Not underestimating the Nature's Protocol, but can you suggest one reason why the crossing over did not take place within the sister Chromatids. The process have to go to the other ways, after Replication and then replicated Chromatids joined and later underwent crossing over.
Please don't escape this question.
its really helpfullll. thank u so much
Yes, Mr. Anderson, that was helpful. Very much so, sir, thank you very very much
THANK YOU SOOO MUCH!!! I have my final coming up and I wasn't really sure about meiosis and mitosis. But I totally understand meiosis now. THANK YOU!!!
+Noelia Coyote Haha same here! Except I'm studying it on the morning of my final!! :) But anyway it is an awesome video thanks!!
2:50 "Do you remember what it means when they look like this..."
My dumbass brain : Amogus
How come we start meiosis with a pair of chromosomes from each parent when meiosis itself occurs before fertilization? Plz answer
I think when he says a pair of chromosomes from each parent he means the person's parents- let's say this was happening in your body, the pair of chromosomes would come one from your mom and the other from your dad. you would form four daughter cells which have only haploid (23) chromosomes that will later fuse with your partners cell to form a zygote- with 46 chromosomes (or 23 pairs)
Wow the video was amazing sir god bless you 🙏❣️✝️ looking forward for more videos like this
I love these videos!
Teacher explained it for the same length of time but left me more confused than I already was, random guy on the internet explains it and it is completely understandable
well done!....just how like my steak
Even the prophase 1 has 5 stages.... could have explained that... although great work.. loved it..
VEROOONNNN
Pambaba
Thank you so much for making science way easier. I was so confused until I watched this video
It was helpful, I wish there was more detailed, it was kind of rushed, and you lacked using terminology like sister chromatids and homologous chromosomes when needed, but thanks.
I Peed On The M-A-T-T! (Ha! Ha!)
That's actually the way I was taught to memorize the phases!
I had an awesome teacher (luckily the same 1) for all my Anatomy & Physiology classes in high school!
Thanks for posting this! It's a great refresher! :)
I loved this, I just had one question...doesn't the spindle apparatus attach to the kinetochore NOT the centromere? I learned that the two are not the same term, the centromere connects the homologues/sister chromatids together, and the kinetochore is a protein bundle that is the site of attachment for the microtubules in the spindle apparatus?
Yes, but the kinetochores are near/on top of the centromere. The centromere is a region where the two sister chromatids are attached but the spindles are attached to the kinetochores in this general region.
What would be helpful is to add when chromosomes are monad, dyad, tetrad, diploid, haploid.
Yes, but you should also incorporate when and where the chromosome get its number halfened.
Can people stop talking a language called science 😭
CLOROX BLEACH How was ur final exam
how can you have one chromosome from mum and one chromosome from dad during meiosis? i thought meiosis was the production of gametes?
Little detail but still good for an overview, ty
If there is a heaven in the other world, you certainly will be in it Mr Anderson, thank you for these videos
Extremely helpful. Your videos are so well done. Paul is an excellent teacher. Thank you.