AP BIOLOGY

Detailed explanation-1: -When cells divide during meiosis, homologous chromosomes are randomly distributed to daughter cells, and different chromosomes segregate independently of each other. This called is called independent assortment. It results in gametes that have unique combinations of chromosomes.

Detailed explanation-2: -During meiosis, homologous chromosomes (1 from each parent) pair along their lengths. The chromosomes cross over at points called chiasma. At each chiasma, the chromosomes break and rejoin, trading some of their genes. This recombination results in genetic variation.

Detailed explanation-3: -Mutations are the original source of genetic variation. A mutation is a permanent alteration to a DNA sequence.

Detailed explanation-4: -The orientation of each pair of homologous chromosomes at the center of the cell is random. This randomness, called independent assortment, is the physical basis for the generation of the second form of genetic variation in offspring.