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Brady Yoon
2005-Feb-02, 03:18 AM
I have a question about chromosomes.

According to my bio text, when chromosomes attach and are held together at the centromere, one of the two parts is called a chromatid. But then it later says that the whole thing is a chromosome, while earlier it said a chromosome is one of the two parts being connected.

I'm confused. Can someone define the following terms: sister chromatid, chromosome, chromatid, chromatin?

And how does a cell know whether to perform mitosis or meiosis? Does a sex cell know that is has to perform meiosis and same with body cells and mitosis? If so, how did the sex cells ever originate?

I think the thing that's got me confused is the word "chromosome" is used so often, and it never clearly explains the structure.

Thanks! :D

One Day More
2005-Feb-02, 03:32 AM
A chromatid is like a half of a chromosome. I believe a "sister chromotid" would be the other half of that same chromosome. The two halves of the chromosome is held at the centromere, making the chromosome. Remember the chromosome arms are made of alleles IIRC. That's about all I can offer, sorry! :cry:

Brady Yoon
2005-Feb-02, 03:46 AM
One more thing, am I correct in saying that when DNA is replicated, it is replicated for both members of homologous chromosomes, and that there would be 92 chromosomes as a result of that?

Makgraf
2005-Feb-02, 06:44 AM
And how does a cell know whether to perform mitosis or meiosis? Does a sex cell know that is has to perform meiosis and same with body cells and mitosis? If so, how did the sex cells ever originate?
Well Brady, when a cell loves itself very much...

beskeptical
2005-Feb-02, 09:48 AM
And how does a cell know whether to perform mitosis or meiosis? Does a sex cell know that is has to perform meiosis and same with body cells and mitosis? If so, how did the sex cells ever originate?
Well Brady, when a cell loves itself very much... :lol: :lol: That's funny.

Here's a site (http://www.biologymad.com/master.html?http://www.biologymad.com/CellDivision/CellDivision.htm) that looks like it has the information you want without all the extra confusing stuff.