BIOL 1107 Lecture Notes - Lecture 8: Gamete, Gametogenesis, Down Syndrome
Document Summary
Meiosis is a type of nuclear division. It results in cells that have half as many chromosomes as the parent cell. In animals it leads to the formation of eggs and sperm. Each cell produced by meiosis receives a different combination of chromosomes. Because genes are located on chromosomes, each cell produced by meiosis receives a different complement of genes. Meiosis leads to offspring that are genetically distinct from each other and from their parents. The leading hypothesis to explain meiosis is that genetically variable offspring are more likely to thrive in environments where parasites and disease are common. If mistakes occur during meiosis, the resulting egg and sperm cells may contain the wrong number of chromosomes. It is rare for offspring with an incorrect number of chromosomes to develop normally. During sexual reproduction, a sperm and an egg unite to form a new individual.
