AP BIOLOGY

Detailed explanation-1: -A process called CROSSING OVER, which occurs only in meiosis, enables offsprings that results from the fertilization of the gametes produced by meiosis to exhibit GENETIC VARIATION i.e. difference in genetic content from parent cell.

Detailed explanation-2: -Genetic variation is increased by meiosis During fertilisation, 1 gamete from each parent combines to form a zygote. Because of recombination and independent assortment in meiosis, each gamete contains a different set of DNA. This produces a unique combination of genes in the resulting zygote.

Detailed explanation-3: -Because meiosis creates cells that are destined to become gametes (or reproductive cells), this reduction in chromosome number is critical-without it, the union of two gametes during fertilization would result in offspring with twice the normal number of chromosomes!

Detailed explanation-4: -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-5: -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.