BIO 351 FINAL EXAM STUDY GUIDE QUESTIONS AND CORRECT DETAILED / VERIFIED ANSWERS LATEST UPDATE

Variation: mutation - ANS mutation = any change in DNA point mutation - ANS point mutation = nucleotide substitution - substitution of one base type in a position for another base type types of mutations - ANS 1. point mutations 2. insertion 3. deletion 4. rearrangement 5. translocation -- a piece of DNA from one chromosome gets moved to another chromosome 6. synonymous mutation - a mutation has taken place, but there is no change in transcription of amino acids or translation of proteins. will not affect the fitness of an individual. however, some codons are better for translation than others define translocation - ANS translocation is a type of mutation where a piece of DNA from one chromosome gets moved to another chromosome define synonymous mutation - ANS synonymous mutation is when a mutation has taken place but there is no change in transcription of the amino acids or translation of proteins. will not affect fitness of the individual. however, some codons are better for translation than others what is the human point mutation rate (per nucleotide per DNA replication) ? - ANS the human point mutation rate (per nucleotide per DNA replication) is ~5^-11 - lifetime mutation rate is closer to 5^-9 (1/200,000,000) - genome -- 3.2e9 base pairs/gamete - 3.2e9 x 5e-9 = approx 16 new mutations per gamete - this means it is practically impossible to pass on DNA to offspring without any mutations present rate of de novo mutations and the importance of father's age to decrease risk - ANS - sequence entire genome of 65 families - found that the # of mutations in the child DIRECTLY RELATED to the AGE OF THE FATHER when the child was conceived - the OLDER the father gets, the more cell divisions that take place before the sperm cell is formed, and this allows for more opportunities for mutation to occur is evolution limited by the supply of variation? what fraction of all point mutations are synonymous? - ANS - 61 codons - each can mutate 9 different ways (3 ways to change base pair in a codon - 3x3 = 9) - of the 549 possible mutations, about 25% cause NO AMINO ACID SUBSTIUTION what if mutation was the only agent of evolution ? what predictions were there? - ANS either fitness will: go up (slowly) fitness will go down OR fitness will stay the same how could you eliminate natural selection? - ANS you could eliminate natural selection by forcing every individual to reproduce EXACTLY THE SAME AMOUNT - rapid decline of fitness in populations of Drosophilia melanogaster maintained under relaxed natural selection (Shabalina, Yampolsky, and Kondrashov - 1997) - began with 100 pairs of males and femlaes from a natural population - one male, one female offspring from each pair - "middle class neighborhood" treatment (MCN) - fitness should DECLINE AS HARMFUL MUTATIO