2006-12-21 13:34:44 · 4 answers · asked by mcrlover862 1 in Science & Mathematics ➔ Biology
Its called a chiasma. It occurs when the chromosomes line up on the equator and swap information. This is why sisters or brothers are different. If this didnt occur each zygote (to fetus) would have the same genome as each other.
2006-12-21 13:40:46 · answer #1 · answered by Sparkle 3 · 0⤊ 0⤋
Okay, kind of a tough one.. Chromosomes can be wise but not always.. I think they develop after birth, although some will argue otherwise. Crossing over is like putting an X over a Y for example..but there's all kind of movement back and forth in Biology reproduction
2006-12-21 13:49:55 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Hi Aldys -
Check out the following site. It's one I frequently refer to my students when they are studying both cell biology and cell division. Click on the link for Meiosis. It will show you animated step-by-step what is happening!
2006-12-21 15:50:33 · answer #3 · answered by tartu_k 2 · 0⤊ 0⤋
It is in meiosis when the two chromatid pairs swap a little segment. It causes variation in allel frequencies..
2006-12-21 13:37:52 · answer #4 · answered by dixie_girl137 2 · 0⤊ 0⤋