We know that variations (differences) within a population are necessary for natural selection to occur. Which of the following is NOT a source of genetic variation?
a. Mutations
b. Independent assortment
c. Crossing over
d. Mitosis
To determine which of the options is NOT a source of genetic variation, we need to understand what each option represents:
a. Mutations: Mutations are changes in the DNA sequence that can introduce new genetic variations into a population.
b. Independent assortment: Independent assortment occurs during meiosis when homologous chromosomes align randomly and separate, leading to different combinations of genes in the resulting gametes.
c. Crossing over: Crossing over occurs during meiosis when homologous chromosomes exchange genetic material, resulting in new combinations of alleles.
d. Mitosis: Mitosis is the process of cell division that produces two identical daughter cells, each with the same genetic information as the parent cell. It does not contribute to genetic variation, as the genetic material is replicated and distributed equally to the daughter cells.
So, the option that is NOT a source of genetic variation is d. Mitosis.