Question

Describe and discuss the following processes by which genetic variation increases:

A. Independent drawing of chromosomes

B. Crossing over

C. Random Fertilization

Answer 1

Genetic variation means differences in the DNA segment between individual and each variation of gene called allele. These variations are advantageous for the survival of species accpording to changing environment. These variation caused by verious processes such as mutation, crossing over , random mating between organism and random fertilization.

Crossing over is a event occur in prophase 1 of meiotic division where recombination occur between chromatids of two homologous chromosome. This process involve exhange of genetic material between homologous chromosome cause reshuffling of allele within the population.

In random fertilization, one gametes from each parents combine to form zygote. Gametes production involve independent assortment and recombination during meiosis therefore, each gametes contain different set of DNA which combine to form unique set of DNA. Here also reshuffling of allele is occur whitin population.

Independent drawing of chromosome means independent assortment of chromosome during meiosis help in the formation of gametes with different set of DNA which combine to form zygote with unique set of DNA . It will help to introduce genetic variation in individual within the population.

Due to all of these process none of two individual look like each other except identical twins. For example we have similarity with our parents but have differences too. We are not alike to our parents or sibiling. Each individual has their own distinguished feature result of genetic variation.