LIFESCI 7A Chapter Notes - Chapter 14: Mutation, Colorectal Cancer, Dna Replication
13 Dec 2017
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Document Summary
Unrepaired damage to dna: due to, reactive molecules produced in metabolism, chemicals in environment, radiation. Insertion or removal of dna sequence near genes. Incorrectly repaired chromosome breaks: due to, reactive chemicals, radiation. Substitution of one nucleotide pair for a different nucleotide pair. Although it is the most common, it is still very rare. Mutation rates differ through organisms: due to errors in replication. Instability of rna molecules: lack of proofreading in replication of genomes. In mammals, there are greater mutations in somatic cells than in germ cells. Examining the rate of mutation across an entire genome in one generation. Rate of mutation depends on: size of genome, number of cell divisions (per generation) Large number of mutations occur in the genome in one generation would be intolerable in organisms with a high density of protein-coding genes. Vast majority of mutations occur in noncoding dna. Mutations account for diversity and uniqueness of individuals. Only germ-line mutations are passed down to offspring.
