Q.What are Genetic variations? Explain the different factors responsible for genetic variations.
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Start your 14-day free trial to unlock the full solution →Genetic variations are changes in gene/allele frequency caused by gene mutation, recombination, gene flow, genetic drift and chromosomal aberrations.
Step 1. Genetic variation refers to any change in the genes present in a population, or in the relative frequency of alleles within it, and is generated by several distinct mechanisms.
Step 2. Gene (point) mutation is a sudden, permanent, heritable change confined to a single gene, which alters the organism's phenotype and hence causes variation.
Step 3. Genetic recombination, arising from crossing over between non-sister chromatids of homologous chromosomes during gamete formation, produces new combinations of alleles, adding to phenotypic variation when such gametes unite at fertilisation.
Step 4. Gene flow is the movement of genes into or out of a population, through the migration of organisms, the dispersal of gametes (e.g. pollen), or the transfer of DNA segments (transformation); it alters gene frequency and hence adds to variation.
Step 5. Genetic drift is a random, chance-driven fluctuation in allele frequency, especially significant in small populations, and includes the founder effect and bottleneck effect. …
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