BIOL 1010U Lecture Notes - Lecture 14: Dna Replication, Mutation Rate, Multicellular Organism
Document Summary
Textbook reference: chapter 14 in biology how life works (2nd ed. ) Why are mutations important: mutation: any heritable change in the genetic material. Rate and nature of mutations: mutation is rare for any individual nucleotide and varies for different organisms, high rates: rn viruses, retroviruses, moderate rates: dna viruses, lowest rates: unicellular organism and multicellular organism, genome wide, mutations are common. Overall mutation rate depends on: number of times dna replication occurs, size of genome. Higher mutation rates for multicellular organism, lowest rates in dna viruses, bacteria, yeast: errors in dna replication in multicellular organisms occur about 10-10 or about 1 nucleotide in every 10 billion nucleotides. Exceptions: hot spots certain nucleotides are prone to mutation differences b/w sexes. In human mutation rate is greater in male than females. 1: cell type - i. e. somatic vs. germ cells. Dna repair: dna ligase seals breaks in the sugar-phosphate backbone.
