AP BIOLOGY

Detailed explanation-1: -Chromosomal crossover, or crossing over, is the exchange of genetic material during sexual reproduction between two homologous chromosomes’ non-sister chromatids that results in recombinant chromosomes.

Detailed explanation-2: -Crossing over is the exchange of corresponding parts between non-sister chromatids of homologous chromosomes producing a new combinations during gamate formation. It occurs during the prophase-I of the first meiotic division.

Detailed explanation-3: -In synapsis, the genes on the chromatids of the homologous chromosomes are aligned with each other. The synaptonemal complex also supports the exchange of chromosomal segments between non-sister homologous chromatids in a process called crossing over.

Detailed explanation-4: -Chromatid exchanges occur between paired homologue chromosomes which are linked together by their sites of junction: the chiasmas. This process, called “crossing over, ” results in genetic recombination, with the consequence that genomes between maternal and daughter cells will not be strictly identical.