Contribution of Meiosis to Human Genetic Diversity - Essay Example

Crossing over is the process that happens in the previous stage of prophase. In this process homologous chromosomes are paired together loosely along their length, resulting in the generation of point of contact which is used for the exchange of genetic information. This produces various combinations of maternal and paternal genes. The number of cross over events depends on the size of chromosomes and the position of their centromeres. In the case of humans, it is one to three on an average The following stages of Meiosis like Metaphase, further increase the chances of more diversified combinations because sister chromatids not being identical twins.

Fertilization is the process in which different gametes fuse together and form new organisms of the same spices. In humans it is a fusion of haploid sperm cell from the father and haploid ovum from the mother, resulting in the formation of the egg. Egg contains two haploid sets of chromosomes bearing genes of mother and father A zygote is produced during fertilization out of about 64 trillion (8 million) diploid possible combinations from the fusion of single male gamete with a single female gamete, Further stages of Meiosis, like prophase, Metaphase, Anaphase, and Telophase, adds further variations due to Independent assortment of chromosomes and crossing over as explained above.

Thus a resulting number of possible combinations is inconceivably large.Some times we think why brothers and sisters are so different in spite of having common parents. Considering the above mechanism, it can be concluded that two human beings can have an identical genome only if they are from the same fertilized egg.