Meiosis
Meiosis is a type of cell division that literary means something less or reduced.It is through meiosis that gametogenesis takes place leading to the production of sex cells also called eggs in females and sperms in males (Raven, 2004). During the process of meiosis, the cell nucleus divides into two distinct phases but the duplication of chromosomes follows thereafter but it only takes place in one fold. This in turn leads to the production of a maximum of four haploid daughter cells. (Alberts, 2000).The fusion of the male and the female games forms the first instance that leads to variation in the genetic composition of the four daughter cells produced by any successful meiotic process of cell division. The fusion of the nucleus of both the male and the female forms the initial step through which the sources of variations that normally arises between offspring as well as their parents (Raven, 2004).
Yet anther factor that may lead to the production of non identical cells is the concept of “crossing over” where the individual chromosomes may break up in the process and join up again leading to variation in the haploidity of the sex chromosomes produced at the final stages of meiosis. Another process that takes place during metaphase commonly known as assortment is also responsible for the sources of variations in the four daughter cells produced during meiosis. (Alberts, 2000). This so called independent assortment of chromosomes involves random pairing of similar or homologous chromosomes at the pole which eventually leads to variations and the observed differences in the four daughter cells produced in the end stage of meiosis as this gives an opportunity for the creation of new gene combinations on the chromosomes.During the process of gene combinations, there is an exchange of the genetic composition in the form of DNA when the two homologous chromosomes are brought together during the process.