BIOL 1000 Chapter Notes - Chapter 10: Gamete, Sporophyte, Microtubule
Document Summary
Ultimate source of genetic diversity occurs by mutations of the dna sequence, made by errors during dna replication. Genetic recombination cutting and pasting dna backbones into new combinations. Genetic recombination ensure that offspring are not identical to parent cell during sexual reproduction. Genetic recombination requires: 2 dna molec. that differ from each other at atleast. Mechanism to bring dna to close proximity, collection of enzymes cut, exchange, and paste dna back together. Homologous regions of dna may be short as a few base pairs or long as a chromosome. Homologous dna are paired and enzymes break covalent bond of backbone of dna and the free ends of the backbone exchange and reattach to other dna molecules. The result is 2 recombined molecules with parts from 2 diff. Cutting and pasting of 4 dna backbones results in 1 recombination event. Genetic recombination historically associated to meiosis and sexual reproduction. It was later proven that bacteria reproduce by recombination as well.
