Question

Identify two mechanisms of recombination that take place during meiosis. Explain how each contributes to an increase in the genetic variation of a population.

Answer 1

1. During meiosis crossing over takes place which results in the genetic recombination. Genes are arranged in a linear fashion on the chromosomes. Linked genes are those which are present on the same chromosomes. During meiosis paternal chromosomes can precisely exchange gene segments with their homologous maternal counterparts. This process gives rise to recombinant chromosomes that occur on specific locations called chiasma during pachytene of prophase 1.

2. During meiosis, the pairs of the homologous chromosome are divided in half to form haploid cells, and this separation, or assortment, of homologous chromosomes, is random leading to genetic diversity. During meiosis, the independent assortment will be made first and then cross over will be made. Genes that are on different chromosomes (like the Y and R genes) assort independently.