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Title: Chromosome, chromatin, chromatid Post by: Orianna117 on Mar 16, 2017 Hey guys,
Can someone plz tell me the difference between chromosomes, chromatids, and chromatins. I know chromatins is the stuff wrapping around histones, and that the X is a chromosome while half the X is a chromatid. But I feel like there is more than meets the eye. Like, we say chromosome exists in the cell at all stages of the cell cycle, but it only replicates past a certain point so it must have been a chromatid, not a chromosome before that stage? Halp plz Thanks Title: Re: Chromosome, chromatin, chromatid Post by: cloveb on Mar 16, 2017 See attached for solution. Also, see the link below for visualizing of the differences.
https://biology-forums.com/index.php?action=gallery;sa=view;id=27198 :) Title: Re: Chromosome, chromatin, chromatid Post by: bio_man on Mar 17, 2017 Such an incredible response above ^^ Here's my take anyway...
In DNA's relaxed state, before the start of mitosis, it is referred to as chromatin - think of spaghetti and meat balls. DNA at mitosis is referred to as a chromosome - condensed DNA. Since at this stage DNA has been copied, a chromosome appears like an ><, but why? That's because when it was copied back in the S-phase of interphase, the newly copied chromatin was connected at the waste with the original. The waist region is called centromere. Each copy of the chromatin is referred to as a chromatid, hence the term chromatid sisters. These sisters, connected at the waste condense into the chromosome we see in the prophase of mitosis. |