AP BIOLOGY

Detailed explanation-1: -Genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism’s offspring).

Detailed explanation-2: -Mutations are the original source of genetic variation. A mutation is a permanent alteration to a DNA sequence.

Detailed explanation-3: -Genetic variation is also introduced by random fertilization of the gametes produced by meiosis. Any of the genetically unique sperm generated by a male may fertilize the genetically unique egg produced by a female. During metaphase I, the homologous pairs of chromosomes are aligned along the metaphase plate.

Detailed explanation-4: -Mutation: The change in the genes of individuals living in a population leads to genetic variation. Genetic recombination: The fusion of gametes promotes the various combination of genes in a population leading to genetic variation.

Detailed explanation-5: -The three main sources of genetic variation arising from sexual reproduction are: Crossing over (in prophase I) Random assortment of chromosomes (in metaphase I) Random fusion of gametes from different parents.