AP BIOLOGY

Detailed explanation-1: -Answer and Explanation: The answer is C. Mitosis of fertilized eggs. Mitosis of fertilized eggs is not a source of genetic variation.

Detailed explanation-2: -For example, there are genetic variations that arise in clonal species, such as bacteria, due to spontaneous mutations during mitotic division. Furthermore, chromosomes are sometimes replicated multiple times without any accompanying cell division.

Detailed explanation-3: -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-4: -Genetic variation is increased by meiosis 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. Recombination or crossing over occurs during prophase I.

Detailed explanation-5: –In case of mitosis, crossing over does not occur. So, there is no chance of recombination as well as genetic variation. Therefore, meiosis leads to significant genetic variation, while mitosis does not.