2006-11-27 15:24:35 · 2 answers · asked by mini 1 in Science & Mathematics ➔ Biology
Cross overs happen between gene locations furthur because there is more distance between to for the chromosomes to touch and cross. If they are closer, there is less area for these chromosomes to touch and exchange genetic information. 1 map unit = about 1% cross overs. If something is 10 map units appart, there is about 10% crosss over and 20 = 20% and so on. If you think about it, its like fighting with two swords. say one gene is at the tip and the other is at the handle (far genes). The chances of your opponent hitting your sword in that region is more likely than between the the tip and 1 inch down from it (close genes).
2006-11-27 15:31:37 · answer #1 · answered by HC 2 · 0⤊ 0⤋
genes that are close together on chromosomes are less likely to be SEPARATED by crossing over. Think about it, for 2 genes to be separated, the crossover needs to happen in between them, otherwise they will stay together. If there is little DNA in between 2 genes, odds are crossing over will not occur there. As a result, they will stay together, and are said to be "linked".
2006-11-27 15:29:00 · answer #2 · answered by Brian B 4 · 0⤊ 0⤋