Lect8_redundancy

Lect8_redundancy - 1 Redundancy: a way of reducing errors...

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Unformatted text preview: 1 Redundancy: a way of reducing errors Day #8 Two assertions to contemplate 1.) Inheritance and Natural Selection are inextricable. You cant have one without the other. 2.) Natural Selection is essential for life. It is needed just to maintain the status quo (never mind innovation or adaptation.) What would happen without natural selection? One-minute paper Mutation is the raw material for evolution, because it is the ultimate source of variation. Life strives to reduce mutations as most mutations are harmful. Explain how both of these statements can be true. One-minute paper Mutation is the raw material for evolution, because it is the ultimate source of variation. Life strives to reduce mutations as most mutations are harmful. Discuss with your neighbor: how can both of these statements be true? One-minute Revision Mutation is the raw material for evolution, because it is the ultimate source of variation. Life strives to reduce mutations as most mutations are harmful. Revise your explanation of how both of these statements can be true. Todays topic Most errors reduce fitness, so organisms that reduce the likelihood of errors (improve copy fidelity) are favored over time. Yet errors can never be entirely prevented. In what ways is redundancy key to reducing the frequency and impact of errors? 2 The Universal Genetic Code is redundant In order for 4 bases to code for 20 amino acids, some redundancy is inevitable. Groups of 1 base = 4 1 = 4 possible aa words Groups of 2 bases = 4 2 = 16 possible aa words Groups of 3 bases = 4 3 = 64 possible aa words Are the chemistries of the amino acids valine and glutamic acid similar? A. Yes B. No C. Somewhat The amino acids can be organized according to the solubility of the R-group in water and its charge. [Acids donate protons and so have a negative charge, while bases pickup protons and so are positively charged.] Mutations can have phenotypic (visible) affects that range from non-existent to subtle to dramatic. How extreme a change in phenotype do you expect from a mutation substituting valine for glutamic acid? A. Subtle or very little change B. Substantial change C. No way to know Are the chemistries of the amino acids valine and glutamic acid similar?...
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Lect8_redundancy - 1 Redundancy: a way of reducing errors...

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