How do chromosomes relate to DNA? Why do they exist at all, if all genetic information is stored in a single strand of DNA within the cell? I read that chromosomes only form when cells are about to divide – if so, why is this necessary and what determines how many chromosomes are formed?
In: 18
Yes, youre right….each “chromosome” is a condensed single molecule of DNA (technically it is two molecules to make it double stranded but in educational spaces its referred to as one).
The chromosomes during non-mitosis phases of cell development do have a relaxed conformation…..imagine the nucleus full of intertwined spaghetti instead of the X shapes you are accustomed to. The chromosomes are always there….they just condense at the right time when cells are trying to coordinate FAITHFUL segregation between the two daughter cells.
What determines how many chromosomes per organism? It all depends species to species. Humans….distinctly have 23….other organisms have different amounts but those numbers are relatively constant *within the species*
Please ask any more Qs as specific as you want. I have a PhD in genetics and explaining this kind of stuff is of way more interest to me than the nitty gritty of research. Seriously……even historical aspects of chromosome research.
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