Meiosis steps | what is the purpose of meiosis - Animated Lecture (Embryology)
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- Опубликовано: 9 июл 2024
- Meiosis steps explained clearly. An important question that "what is the purpose of Meiosis" is addressed in this video.
In this visual lecture Dr. Aizaz talks about:
00:00 Intro to Meiosis
03:26 Importance of Meiosis
06:01 Prophase 1
07:12 Homologous chromosomes
12:55 Synapsis, Synaptonemal complex, crossing over and chiasmata formation
19:31 Metaphase 1
21:24 Anaphase 1
23:03 Telophase 1
23:29 Cytokinesis 1
23:49 Meiosis 2
25:51 Animated Review of Meiosis
26:55 Mitosis vs Meiosis
Website: www.medicovisual.com
Email: draizaz@medicovisual.com
Bestest video ,i have ever got.
Best explanation till date ,kudos and thank you so much,sir😊
Excellent. Much effort in the graphics!! Well done.
Finally understood meiosis really well...very nice effort...looking forward to more such videos.
Thank you so much
Thank you soo much
You are vidéo is detailed and simple
Thank you very much for your video lectures they are both entertaining and more easy to understand!
Thank you for this great explanation
Well done sir hats off u earned my respect ❤️❤️❤️❤️❤️
Thank you very much for this understanding lecture 🎉🎉
Best class. Thank you so much❤
Wow !!
Honestly not an easy concept to digest but you made it really digestible and animations have really helped.
One suggestion:
Add 2n4c -> 1n2c->1n1c
In respective images especially the last one in comparison of mieosis
Este señor acaba de salvarme el examen de reproducción celular, dios le bendiga
Thank you so much you explained it so well...
You are most welcome
Thank u so much sir...really helpful...please keep uploading more on different topics....your method of teaching is really easy to understand...
Thank you so much for appreciation
Tanks so much..now I really appreciate meiosis and mitosis
You're welcome
Now I understood the concept.Firstly after consulting standard textbook Emery's Genetics I was commenting. Great 👌 effort ,thanks for video and detailed reference.
1.Meiosis never occurs after fertilization as you mentioned father side and mother side of same cell just prior to fertilization.Confusion was arising if no fertilization or zygote is formed how can mother and father both side is involved ? Answer I am realising that you discussed was F1 generation's father and mother set of chromosome in F2 offspring cell which will fertilize later forming F3 gen.cell ; here father mother side refers to chromosome set of F1.Ques.then how 4 haploid sperms form by spermatogenesis Ans. Before fertilization.But secondary oocyte to ovum formation requires another centriole that it recives from sperm after fertilization.
2.Chiasma (TERMINATES) breaks at anaphase BUT it terminalizes at diakinesis of prophase 1.
AT LAST SORRY FOR IF I WAS IN ANYWAY RUDE I WAS SIMPLY CONFUSED AT CERTAIN POINTS AND WAS PANICKING 😅YOUR REPLY CLARIFIED MY DOUBTS ,THANKYOU FOR SUCH GREAT DISCUSSION😊😊😊🙏🙏
Dear @iplcricketblog507,
Thank you for taking the time to engage with the content of my lecture and for your acknowledgment of the effort that goes into creating these educational videos. I am sincerely committed to providing accurate and valuable information, and your feedback is essential for maintaining the quality of these lectures.
I would like to address the concerns you raised:
1. Regarding Meiosis occurring after fertilization, there might have been a misunderstanding. Meiosis indeed does not occur immediately after fertilization, which is an indisputable fact. At no point did I suggest that Meiosis takes place immediately following fertilization. Instead, I explained the significance of Meiosis in the context of the life cycle, noting that after two haploid gametes fuse during fertilization to form a diploid zygote, this zygote develops into a newborn. Then, as this individual reaches reproductive maturity, Meiosis occurs in their reproductive cells to produce haploid gametes for the next generation. This cycle ensures genetic diversity and stability across generations.
2. As for the termination of chiasmata, I have referred to several authoritative textbooks that support the statement made in the lecture. Chiasmata are indeed dissolved during anaphase I, not diakinesis. The confusion might arise from the difference between 'termination' and 'terminalization' of chiasmata. Terminalization-where chiasmata move towards the ends of the chromosomes-is distinct from their termination, which signifies the complete dissolution of the chiasmata, allowing for the separation of homologous chromosomes.
This distinction is supported by several authoritative texts, including:
- "Lodish Molecular Cell Biology" (8th ed., Fig 19.37 and 19.36)
- "Human Embryology Made Easy" by M. Waheed Rana (p. 8)
- "Human Embryology and Prenatal Development" by Hamilton, Boyd, Mossman (4th ed., p. 9)
- "Textbook of Histology" by Leslie P. Gartner (Fig 3.18, page 76)
- "Histology; a text and atlas" by Wojciech Pawlina (p. 90)
For your convenience and further reference, I have included snippets from these books which can be accessed here: www.medicovisual.com/112/files/65d65b2008d1a_1708546848_eye-optic-sulcus-references.pdf
P.S. I have noticed that some online resources like BYJUS have wrongly mentioned that chiasmata dissolve during diakinesis.
I am genuinely disheartened to read such remarks, especially given the extensive research and hard work that goes into preparing these lectures, which include careful study of numerous books and articles. Rest assured, I am dedicated to correcting any inaccuracies and continuously improving the educational content provided.
Your engagement is invaluable, and I encourage you to continue this dialogue to help enhance the learning experience for everyone. If there is any part of the lecture that remains unclear, please feel free to ask, and I will do my best to explain further.
Warm regards,
Dr. Aizaz
MedicoVisual
Thanks a lot sir and definitely your efforts are commendable whole embryology discussion that in whole youtube no one has gone that depth and completion it's like learning Langman but with great discussion and visualization. Again thanks...
Best explaination of thisss chapter . Thankyou sir🙌
Thank you so much for your appreciation
thank you soo much sir..it was very clear..please keep uploading more videos for medical students
You are most welcome. And thank you so much for such words of appreciation
Nice😍😍😍
U had explained it very well
Thank you so much
Very explanatory presentation using graphics. Excellent work. Upload more such videos for medical people
Thank you
Thank u mamm
Really cleared everything. Tho watched it in x1.5
Lol. Thanks a lot
Thank you sir
My pleasure
sir what is cohesion ring at anaphase 1...i read this line at a slide ..this cohesion ring gets cleaved its mentioned
very nice subhanaAllah
Thank you
Thank you very much.👌
So nice of you
Good lecture
Thank you
Sir, I have a question ... all over body cells have same kind of chromosome right ?
Only thing is that crossing over occur only in meiosis otherwise gamete cell have same chromosome as somatic cell right? So somatic cell can go under meiosis if they want to?
Thank you so much sir🙏🙏... Crystal clear hogya 👍👍
You are most welcome
Are you still confused about something ? Feel free to ask. I will try my best to explain
@@MedicoVisual I have confusion in alleles and also alleles in dipolid and haloid organism...for example how we come to know that for a particular character there is one allele in haploid organism like neurospora
@@MJ-db4tf Almost every characteristic of the body is manifested by structural or functional proteins. And the recipe to synthesize these proteins lies within the sequence of nucleotides in the DNA, and this recipe is called gene. In other words, gene is the sequence of nucleotides in the DNA that encodes a particular protein (Although gene can also encode a non-protein product e.g. RNA but lets not go into that discussion right now).
Chromosome is nothing but highly condensed and coiled DNA.
Allele is the particular location of any gene on the chromosome (DNA). A molecule of DNA, condesned into a chromosome does not contain a single gene, but multiple genes. Suppose that chromosome number 4 contains the gene for hexokinase enzyme near it's lower end. So, this particular position where this gene of Hexokinase enzyme is present (the lower end of chromosome no 4) is called "allele of the hexokinase gene". Another gene may be present on some other position and that position is the allele for that gene.
In Diplpod organisms e.g. Human, we have two copies of chromosomes (one from father, other from the mother) so we have 2 copies of each gene. The end product of these two genes may be slighly different (although both will be coding for the same protein). For example the gene present on chromosome from father may be encoding a defective hexokinase and the chromosome from mother may be encoding a normal hexokinase.
I do not know much about Neurospora as I am a Medical Doctor and we study human biology only but I suppose that because it's a haploid organism it may be contaning only one copy of each gene (unlike diploid organism who contain two copies).
Are you clear now ?
@@MedicoVisual Yes sir I got your explanation very well..thank u very much sir🙏
Funny how I have been to many lectures on mitosis/meiosis and it's this video that saved me☺️
Keep up the good work Dr!
Thank you for a great lecture I noted it down! I wish there where also adnotations about gametes phases, like which phase happen in primodial vesicle, which in oogonium, oocyte I, oocyte II. Time is also very important, if I remember corretcly, there is a first developmental block in oogenesis in diplotene phase and next one in metaphase II. I am often confuse when combining this all issues- gamete stage, age, phases - together.
Please checkout this video for Oogenesis ruclips.net/video/UYdh5gmirBo/видео.html
Remaining will be discussed in the upcoming video
Also watch this video for detail of Prophase 1 ruclips.net/video/ddaaBZUV-fY/видео.html
Thank you. I Am looking forward for next video
@@Sarnie.Malowidla I will record it within a day or two
Sir can you upload a video on problems regarding to the topic of cell division and cycle it will help a lot.....and ur this lecture was really good....👍
Which problems ?
@@MedicoVisual amount of dna and no. Of chromosomes and all.....
@@harsh0109 ruclips.net/video/37m7ZGJ3ywQ/видео.html
ruclips.net/video/327RZ1XVpI4/видео.html
Watch these two videos
at what stage of meiosis is haploid number of chromosomes achieved?.....is it after meiosis 1 or meiosis 2?......
also, when does replication occur?....is it before meiosis 1 or before meiosis 2?
Sir if meiosis occurs in gametes so how can there be both paternal and maternal chromosomes before fertilisation ....as paternal and maternal chromosomes come together after fertilisation , in the zygote ...so how they occur in a singal gamete?
Each and every cell of your body (somatic cell) has two copies of each chromosome. One from your father called paternal copy and the other from your mother called maternal copy of choromosome.
There are 23 copies from father and 23 from mother. Thats why we say, Humans have 23 "pairs" of homologous choromosomes.
These homologous chromosomes, pair end to end to form gametes.
I hope you understood. if not, feel free to reply back.
@@MedicoVisual Thank you sir ..now I understood .
sir humun blood cell can undergo mitosis??if yes how plz explain!
No, a mature Red Blood Cell can not undergo mitosis. It does not have a nucleus
Sir but meiosis occur before fertilisation so how can homologous pairs from sperm and ovum happens??????
Sorry I could not quite understand your question. kindly elaborate it.
Sir plzz make a video on giant cell tumor of the bone
I would try to do it as soon as possible
Do you have any particular questions that you want to be specially addressed in the video?
@@MedicoVisual yes sir. Can you elaborate the different types of cells found in it microscopically and their origin
@@firdusarayasmin3245 okay
Do you have any video on genetics
Not yet. Will think about it after I wrap up Embryology. Thanks for the comment.
Someome says hmmmm in middle of this lecture 😂😂😂
😂 doing something
Good lecture
Thanks for liking
Thank you sir
You are most welcome
@@MedicoVisual r u a doctor
@@aleenasiby387 Yes
@@MedicoVisual sir my ambition is to become a doc but iam bad at maths
@@aleenasiby387 An in-depth knowldge of Mathematics is not required to become a doctor