BIOL359 Chapter Notes - Chapter 5: Silent Mutation, Genetic Drift, Deoxyribose
11 Jan 2015
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Mutation = ultimate source of all genetic variation, allows forces like natural selection and genetic drift to act on. Meiosis = creates genetic variation, shifts existing alleles. 4 carbon sugar called deoxyribose, phosphate group, distinctive nitrogen-containing base. At cg pairing: cytosine and thyminen are pyrimidines (just hexagon, adenine guanine are purines bigger structure (hexagon+pentagon) Transition = substitution of a purine with a purine or a pyrimidine with a pyrimidine. Tranversion = substitution of a purine with a pyrimidine, vice versa, more likely to change shape of a molecule, error corrections more likely to detect conformational change. Indels = insertion or deletion of one or more nucleotides in dna sequence, causes. Jumping gene = inserts chunk of sequence into middle of protein. Point mutations result in new alleles which have associated fitness effects. Silent mutations not always neutral, and mutations that change amino acid not always neutral either. Heterozygote superiorty as individual has fitness advantage in malarial environ.
