Question

Describe the ways in which meiosis contributes to genetic diversity within a population in which 2n=20.

Answer 1

meiosis is the process of reduction division in which a diploid cell (2n) produce haploid (n) germcells or gametes. Here 2n=20 so after meiosis germcells with n=10 chromosomes are produced. From a single diploid cell four haploid cells are formed after meiosis. these 4 cells will be genetically different from the parent cell. And also the 4 cells will be different from one another also.That means each cell will be with a unique combination of the genetic material in comparision with the starting cell.

It is because during meiosis crossing over occur. Crossing over is the exchange of genetic material between each pair of homologous chromosomes (parental chromosomes). Moreover random orientation of homologous chromosomes during metaphse of meiosis I also a leading cause for genetic variation.

Random orientation means, there are 2 chromosome from each parent which will seperate into two cells but this occur independantly. Thus if there are 4 chromosomes in a cell they form 2 homologous pair, they can arrange in 4 ways (22). HHere there are 20 chromosomes forming 10 pairs of hoomologous chromosomes and thus 210 ways of different possible gametes are possible apart from possibilities of crossing over.

Fertilisation occur randomly thus again increasing the possibility of variation . 1 out of 8 million sperm fuse with an egg.