Variation - Variation Sexual reproduction promotes...

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Variation Sexual reproduction promotes variation because each gamete (sperm or egg) contains a mixture of genes from two different parents. Crossing-over and Independent assortment promote variation. During prophase of meiosis, crossing-over results in chromosomes that have some genes from one parent and some genes from the other parent. Individuals contain two sets of each chromosome but gametes contain only one set. For each homologous pair of chromosomes, one chromosome will be randomly selected for each gamete formed ( independent assortment ). Variation is necessary for natural selection . Recall that natural selection favors individuals with characteristics that are best adapted to their environments. Variation is therefore necessary for species to become adapted to their environment and it enables them to change when the environment changes. Gametogenesis Gametogenesis is the formation of gametes. The formation of eggs is oogenesis and the formation of sperm is spermatogenesis . In animals, gametes are formed by meiosis.
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This note was uploaded on 01/04/2012 for the course BSC BSC1005 taught by Professor Orlando,rebecca during the Fall '10 term at Broward College.

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Variation - Variation Sexual reproduction promotes...

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