When two gametes combine, they result in a haploid cell, which undergoes the process of meiosis. This form of cellular reproduction is also called reduction division, because more cells are created by the replication and division of components in an original cell. This is how life develops in most complex organisms that reproduce sexually, and is the foundation for the creation of cells in large animals. Ultimately, meiosis results in fully developed living creatures that possess two sets of chromosomes throughout the cells of their entire body.
Once the animal has developed to maturity, this process is mainly for the regeneration or repair of cellular structures that already exist in the body. Some cells lose their ability to divide in this manner after they reach maturity, while others, such as those found in the liver, maintain their ability to reproduce themselves in order to more easily repair damage. Cell division as the sole means of reproduction is typical of unicellular life such as bacteria.
