Mitosis Phases - Animated Lecture (Embryology)

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MedicoVisual - Visual Medical Lectures

Күн бұрын

Пікірлер: 31

@sandhyadas5188 Жыл бұрын

Dr Aizaz Ahmed, you are doing a marvellous job. The concept & the animation!!. You are one of the best teachers, seen in my life. 🙏🙏🙏🙏

@georgeiribar8412 Жыл бұрын

Excellent lecture. Most teachers dont explain that there are 92 cromatids dividing during mitosis.

@janvi3120 3 жыл бұрын

Thank you so much for this sir u r literally the best teacher on KZbin ! I was searching for this for very long especially about chromosome .u cleared all my doubts ! 🙏

@firdusarayasmin3245 3 жыл бұрын

Such a good teacher you are

@MedicoVisual 3 жыл бұрын

So nice of you. Thank you so much.

@Sajal_Sajal 9 ай бұрын

Thank you for clearing my doubts

@hellenmaina3045 Жыл бұрын

Very easy to understand, thank you

@harsh0109 4 жыл бұрын

Sir you gave a very brief lecture and it was a very nice one 👌....

@MedicoVisual 4 жыл бұрын

Thank you so much

@legoabhi2876 2 жыл бұрын

Thank u so much it helped a lot😁

@anwarsultana1776 4 жыл бұрын

You have done very hard work to prepare lecture using graphics

@MedicoVisual 4 жыл бұрын

Thanks a lot

@anwarulhaq535 4 жыл бұрын

Very informative lecture

@MedicoVisual 4 жыл бұрын

Thank you

@vincentpinto1127 10 ай бұрын

Thank you very much for your excellent presentation. I greatly look forward to learning from this entire series with your very detailed work and commentary. However, when the lady asked you "if this is a chromatid, then what is a chromosome?", you should have said it is actually a chromosome. Even before duplication during S phase of Interphace, when there are 23 pairs of loose "chromatids", they are ACTUALLY chromosomes. We do NOT say that the trillion cells in our body have trillion sets of 23 pairs of chromatids!! Now it is very very true that perhaps the tightly packed STATE of the chromatids are called chromosomes. Of course, we may want to additionally add that when the centromere is in place in a tightly packed chromatid, we could call it a chromosome, to help with duplication at the same centromere. Definitially, this is a subordinate matter. We must keep in mind that in the loose stage PRIOR to duplication, the cell STILL has 23 chromosomes that came from the father and 23 chromosomes from the mother. This is very important terminology. But a single chromatid is still a single chromosome (even though loosely packed). For the sake of clarity for your video, please agree with this or correct where I was confused with the nomenclature. Thank you.

@MedicoVisual 10 ай бұрын

Thank you so much for your comment. A chromosome typically consists of two identical sister chromatids joined at a central constriction called the centromere. These chromatids are essentially mirrored copies of each other, containing the same DNA sequence. A single chromatid simply lacks its partner. It remains a single DNA molecule but doesn't fulfill the complete definition of a chromosome. Nonetheless, some textbooks label the single chromatids too as a chromosmes.

@vincentpinto1127 10 ай бұрын

@@MedicoVisual That is my concern. Let's leave proliferative cells aside for now. If we consider stable cells in one's body, say the liver, which are waiting in G0 state, their nuclei will all have 23 pairs of chromosomes in the loose state. We do NOT say they they have 23 pairs of chromatids. Now, if someone DOES want to assert that the "chromosome" HAS sister chromatids, then one MUST necessarily mean that the cell has gone PAST S phase of Interphase, and is stuck there, else it could NOT have mirrored copies! Is that what the state of a stable cell nucleus is at, say in ones liver is at, and is waiting there for some trigger to move it into Prophase of Mitosis?

@MedicoVisual 10 ай бұрын

Thanks for the reply. For a resting (stable) cell that is not actively proliferating, the "chromosomes" are out of the question, anyway. This is because their genetic material is NOT condensed into chromatids or chromosomes, instead, it is loosely arranged in the form of chromatin material. Having said that, I took a deeper dive and found a citation that favors your viewpoint. Devlin's Biochemistry with Clinical Correlates 4th ed., page 603 states that "Each chromosome is characterized by the presence of a centromere". So, even if there is a single chromatid, as long as it is condensed in a particular three-dimensional shape and has a centromere, it can still be called a chromosome. This view is also endorsed by Dr. Najeeb. Here, let me open another mystery box. I have a question for you. Is there any cell (or cell state) possible that has all the nuclear material properly arranged and condensed in the form of single chromatids only? I mean, if you look at the cell cycle, there is the G1 phase, then the S-phase (where chromatin material is duplicated/doubled to form future sister chromatid), then there is the G2 phase and finally the M-phase (Mitosis phase). Now, a stable non-dividing resting cell is typically arrested in the G1 phase (also sometimes called the G0 phase), has nuclear material in the form of loosely arranged chromatins. But when it plans to divide it will first go to S-phase and duplicate itself. So, by the time it reaches the Prophase of M-phase, naturally all of its chromosomes are in the form of two sister chromatids attached at the centromere. (There will be no chromosome having a single sister chromatid). So, as per my understanding the only state when single sister chromatids remain is the Anaphase (which is a transition state only). In order words, the chromosomes almost always have two sister chromatids attached at the centromere. (except for a very short time during anaphase). Isn't it? So, why do you want to call a single chromatid with a centromere, a chromosome (which seldom exists practically)? 😉 I want to conclude by saying that I don't see myself as an expert. I'm constantly learning and see myself as a student of science, eager to learn more every day.

@houriak848 9 ай бұрын

Hi , I think a single chromatid is also called a chromosome cuz by definition" a chromosome is condensed form of chromatin with one centromere "if we think like ur way that the only Stage anaphase which is the shortest and brief we see single chromatid but there's also the G1 phase which is longest and the chromatin equal to chromosome with one single chromatid. We call cell in stable stage that it has 23 pair chromosome although there's no chro just chromatin it's just I think for clarification so we can imagine the quantity there cuz we can't even say "23 " genetic material in that state is like a ball .

@MedicoVisual 9 ай бұрын

@@houriak848 Even in G1 phase, DNA is loosely arranged as Chromatin fibrils. Though I agree with you. Many textbooks classify single chromatid (with a centromere) too as a chromosome. However, there is still discrepancy in literature.