About Gender - Genetics Meiosis and Fertilisation.
Sex is a complicated way for an organism to reproduce itself.
The answer lies in the complex process of cell replication known as meiosis, and the way it works holds one of the keys to evolution. It is only possible to do this during the final stages of cell division. This way of displaying and representing a particular sample of DNA is known as its karyotype. Under normal conditions, the chromosomes, each being a molecule of DNA are packed together in the nucleus. The total length of chromosomal DNA for a human is about two metres.