Question

Discuss how crossing-over leads to greater variability of phenotype's. Give an example to help explain your answer.

Answer 1

Crossing over happens in prophase I of meiosis I when the inner chromatids of two synapsed chromosomes trade a section. This gives those two chromatids a different lineup or a different combination of alleles than they had before. So the gametes containing these recombinant chromatids will have the new combination, as will any offspring from those gametes!

Answer 2

Crossing over happens in prophase I. Chromatids of two synapsed chromosomes trade a section. This gives those two chromatids a different combination of alleles. So the gametes containing these chromatids will have the new combination, as will any offspring.

This is the revised version so that maybe you can under stand it a little better.