I wish I could have watched all these videos when I was a Biology major. I bet my GPA would be a 3.4 instead of a 2.9. Your conviction and clarification of these topics are impressive sir!
Great explanation of the relationship between DNA, Chromatin, and Chromosomes.. I did not realize they were all the same thing - - just different coil levels...
small part of lecture is wrong, two sister chromatids are exactly same and this is why we consider each centeromere as one chromosome even when it is on the one chromatid strain. In fact, pair chromosomes are 2 different chromosomes (each one has one centromere) that come from two parents.
yes I agree even when he talks about haploid and diploid they have both 2n = 4 and it's wrong ! the diploid cell must have 4 chromosomes while the haploid cell has just 2 chromosomes
7:03 might help as a time stamp, as this is the first time he goes wrong, as far as I can tell. When he points to the left part of the chromosome, that would rather be sister chromatid number 1. When he points to the right half of the chromosome, that is sister chromatid number 2. Both chromatids are identical copies of one another (made during mitosis for instance). These two halves are not however from two different parents.
Unfortunately some aspects of this lecture are wrong. This channel is still my favorite overall for studying science. Every educational channel I have looked at has an error once in awhile, nobody's perfect.
Wow amazing .every time I got confused about any thing in bio chemistry just listen to ur videos that confustion absolutely goes away .may god bless u &award u PROF 😍😍😍
Hello, thanks for your great lectures! At 6:40 you said that one chromosome comes from the mother while the other comes from the father. However it looks like that the representation of the chromosome in the board is a single duplicate chromose with two sister chromatides. Am I right? Is it possibile, naturally, two homologus chromosomes (one from the father and other from the mother) joined by a centromere? Thanks.
can you differentiate homologous chromosome and sister chromatid.i think you are calling chromatid as homologous chromosome.may be I m wrong please clear my confusion.otherwise it was really helpfull and I m your big fan.
Sir, I think that the DNA molecule is not wrapped around individual histones(H-2A, H-2B, H-3 and H-4) in a nucleosome. But instead it is wrapped around the core which is made of the above histones.
If I keep thanking God until tomorrow because I found you, it will not be enough ... I prefer not to praise anyone until I make sure that he really deserves it but you always prove yourself worthily, I do not know whether you have a mind in your head or an encyclopedia because I always search for different topics and watch a lot of videos but Surprised that you have explained it too, and in fact, almost these videos Consider as a waste of time in front of your videos,…I am not sure what is the reason that does not make you much more famous!
Thank you for your great job, I really do appreciate your channel. But I must give reason to some people below: "small part of lecture is wrong, two sister chromatids are exactly same..." @Sina Nouraei Further more the two sister chromatids of one prophase chromosome are the product of the semiconservative Replikation of one DNA Molecule which occurs during the S-Phase of the cell cycle. Do you agree with me? Have you ever consider to change the picture behind you? The "haploid" cell on the right isn't the haploid counterpart of the cell on the left. This cell is diploid - if we consider the two cells of the same exemplary organism - The cell on the right seams much more to be one of the daughter cells of the cell on the left after mitosis. or?
Ur lectures are amazing... I am confused though now. Whenever its in x shape, it should be 2 sister chromatids, meaning its an exact copy ,, meaning its already passed the S stage where each chromatide is copied and then paired using a centromere? Is it!!
I had one question, the two chromosomes joined together through the centromere is called homologous chromosomes in this lecture; but in the next lecture (Cell cycle and interphase), you called them sister chromatids. which one is correct? Im very confused, I need answer please....
Could you please clear up the sister chromatid, chromosome thing? Feel like you got it wrong in the video and have confused a lot of people including me.
During cell division, a chromosome basically replicates its information thus creating two sister chromatids that are conjoined by a centromere. When it comes to chromosomes, in a homologous pair, one comes from the mother while the other one - from the father.
While your videos are 99.9% awesome and I can never acquire as mich knowledge as you, I believe that you've made a mistake with regards to what a homologous chromosome means and what a diploid and haploid chromosome mean.
In a homologous pair of chromosomes, one comes from the mom and the other from the dad. So is each chromosome in the pair made of a different DNA molecule (one from the mom and one from the dad)? Might be a dumb question but I am trying to self-learn genetics as I haven't taken the course yet :/
I think that chromosomes are counted by number of centromeres. So here we have one chromosome with two chromatids. But you are equating one chromatid with one chromosome. I need clarification
I love biology but I ain't in biology class stuck in physical science its alright but I love DNA and RNA it's fascinating. Now i am planning on a expirement but i only know one. But i want to know another expirement to preform.
Just watched this video and that chromosome your showing on the left is a single chromosome after replicating it's DNA. Those are sister chromatids connected at the centromere, not two separate chromosomes. Also, the two cells on the right your showing as haploid and diploid have the same number of chromosomes, the only difference is that the cell on the left has replicated it's DNA, thus has completed S phase of the cell cycle, and the cell on the right has not yet replicated it's DNA, thus has not yet entered S phase of the cell cycle. So in the case above both cells on the right have the same number of chromosomes.
Question about maternal and paternal chromosomes - in the diagram of the chromosome you pointed out that one was from the maternal and the other from the paternal. I thought that there was two homologous pairs and that the diagram you presented is one of them. I understood that the chromosomes are as you displayed on the whiteboard during replication and the the two parts are the sister chromatids. Could you please explain for me or maybe link me to a video that explains. I am learning about this for my job. Thank you so very much. LA
Sister chromatids are not from different parents..its the 2 chromosomes of the homologous pair that are from different parents and have different genes
i m confused here you said single chromosome is two chromatids each from different parent. isn t the homologous chromosomes that are each from each parent and that a single chromosome is duplicated chromatid from the same parent.?
Yes, you are correct. In each pair of homologous chromosomes, one comes from the mother and the other one - from the father. Chromatids are just a copy of each chromosome that is created and used during cell division.
:eerrrr.... problem (7'10'') a chromosome is all the "X form", not only the half ! The half is a chromatid and the other is a copy of it (the exact copy of the other except in some cases like the crossing over...). One chromosome of the pair is inherited from the father and the other (the over X composed also of two chromatids) is inherited from the mother. Warning.
