AP BIOLOGY

Detailed explanation-1: -Homologous recombination between areas of concentrated repeated sequences frequently creates deletions and duplications. Because they commonly involve more than one gene, the disorders caused by these large deletion and duplication mutations are often severe.

Detailed explanation-2: -Gene duplication can occur as the result of an error in recombination or through a retrotransposition event. Duplicate genes are often immune to the selective pressure under which genes normally exist. This can result in a large number of mutations accumulating in the duplicate gene code.

Detailed explanation-3: -Duplication, as related to genomics, refers to a type of mutation in which one or more copies of a DNA segment (which can be as small as a few bases or as large as a major chromosomal region) is produced. Duplications occur in all organisms.

Detailed explanation-4: -Duplicated genes are also called paralogs in contrast to orthologs, to refer to their homologous relationship, i.e., the fact that they descend from a common ancestor via a duplication event rather than a speciation event.

Detailed explanation-5: -In the eukaryotic cell cycle, chromosome duplication occurs during “S phase” (the phase of DNA synthesis) and chromosome segregation occurs during “M phase” (the mitosis phase).