BSC 2010 Lecture Notes - Lecture 13: Mitosis, Photolyase, Alkylation
7 Mar 2016
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Document Summary
Mutation- change in the composition of the genome from parent to daughter strand: (total genomic damage repaired damage) = mutation, occurs in somatic and germline cells, ultimate source of genetic variation. Only considering heritable mutation (occur in the germline cells) Mutation is the source of the different alleles: categories. Point mutation (base substitution: substitution of one nucleotide for another at a, rates vary homologous site. Generally around 10^-8 10^-10 per site per generation. Varies by taxon: occur anywhere in the dna sequence, chemical types of point mutations. More common easier for the polymerase to mistake like for like. Transversions- purines changing to a pyrimidine: silent/synonymous substitution. The mutated codon codes for the same amino acid and does not make a difference in the protein sequence. Replacement mutation- the opposite of the silent substitution. May code for a premature stop codon. Once inversion occurs, recombination is usually prevented because recombinant gametes cannot get a full complement of genes.
