NEET BIOLOGY

Detailed explanation-1: -Genetic variations can arise from gene variants (also called mutations) or from a normal process in which genetic material is rearranged as a cell is getting ready to divide (known as genetic recombination). Genetic variations that alter gene activity or protein function can introduce different traits in an organism.

Detailed explanation-2: -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-3: -Mutations are the original source of genetic variation. A mutation is a permanent alteration to a DNA sequence.

Detailed explanation-4: -Definition. A mutation is a change in the DNA sequence of an organism. Mutations can result from errors in DNA replication during cell division, exposure to mutagens or a viral infection.

Detailed explanation-5: -Natural selection acts upon two major sources of genetic variation: mutations and recombination of genes through sexual reproduction. Most mutations do not affect the reproductive fitness of individuals–some may be beneficial, some may be harmful, and many may be neutral.