Sexual reproduction provides a mechanism to produce genetic variation, as the genes of two different individuals are arranged in various ways. This requires a reduction in the chromosome number of the parent cell, normally diploid, to half that, or haploid, in somatic cells. The type of cell division resulting in half the chromosome number of the parent cell is called meiosis.
In meiosis, a germ cell divides into four haploid gametes. When two gametes, typically an egg and sperm for most animals, combine during fertilization to form a zygote, the diploid chromosome number is restored. Meiosis consists of one DNA replication and two nuclear divisions, meiosis I and II. This results in the formation of four daughter cells, each with only half the number of chromosomes of the
parent. Continue reading ‘Sordaria Genetics Background’
