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Biology Laboratory Manual, 6/e
Darrell S. Vodopich, Baylor University
Randy Moore, University of Minnesota--Minneapolis


Meiosis

Meiosis, the process of nuclear division that reduces the number of chromosomes in the resulting cells by half, is what allows for sexual reproduction. In order for two individuals to produce offspring with the same number and types of chromosomes as themselves, they need to evenly reduce the number of their chromosomes by half in some cells. These cells with only half the chromosomes (referred to as ‘haploid’) will then combine with the haploid cells of another individual to produce a new individual with the same number and types of chromosomes as the parents.

Sexual reproduction allows for greater diversity in a population. When two individuals sexually reproduce, they bring forth a new individual with a unique mixture of genes. This variety of genes in a population allows for more diversity of characteristics and an overall stronger population. This strength is shown in a population’s ability to adapt and evolve to changes in the environment.

Asexual reproduction, the process by which organisms basically clone themselves, does not allow for the same level of diversity as sexual reproduction. Because each individual in the population is basically identical to all other individuals, there is very little variation. Overall, the population is less likely to adapt and evolve to a changing environment.