AP BIO genetics HELP

<p>can someone explain to me what exactly is a sister chomatid. i kinda of understand but i instead have a couple of questions about the picture of the sister chromatid so if i can send someone an instant message on aim or private message on CC can you please let me know.</p>

<p>A chromosome is made of two sister chromatids attached at the kinetochore. They're the two halves of the X shape. > <</p>

<p>ok. is half of that x (>) half of the double stranded DNA. therefore both sides of the x make a double stranded DNA.</p>

<p>each sister chromatid contains all of a cell's genetic information (DNA), so that when the sister chromatids split during anaphase of mitosis, each daughter cell has all the identical DNA information of the parent cell. a sister chromatid to a chromosome is produced during the S phase of interphase during DNA replication.</p>

<p>hope that helps?</p>

<p>P.S. i'm pretty sure its not the double stranded DNA you were talking about...</p>

<p>so then each side of the x represents one full double straned DNA, right?</p>

<p>correct. </p>

<p>in other words, when you have two sister chromatids joined at the centromere, that still equals only 1 chromosome. alternately, when they are split apart during anaphase of mitosis, each chromatid equals 1 chromosome, producing 2 total chromosomes.</p>

<p>greatlly appreaciated</p>