Chapter 4: Mutation and Genetic Variation

1.	Deciphering the structure of DNA and determining the relationship between DNA and proteins inspired an explicitly molecular view of genes and their products. Correctly match each term with its most precise definition. [Hint] Using the pulldown boxes, match each item on the left to the corresponding item at right. A. versions of the same gene that differ in their base sequences. B. a change in a single base sequence of a gene C. stretch of DNA that codes for a distinctive type of RNA or protein product D. any change in the base sequence of DNA Choice A Choice B Choice C Choice D Gene  [Hint] Choice A Choice B Choice C Choice D alleles  [Hint] Choice A Choice B Choice C Choice D mutation  [Hint] Choice A Choice B Choice C Choice D point mutation  [Hint]
2.	When we say that the genetic code is redundant, we are referring to the fact that [Hint]
3.	Point mutations that result in a change in the amino acid sequence of a protein are called _______ mutations; those that result in no change are called _______ mutations. [Hint]
4.	Analyses of loss-of-function mutations underestimate actual mutation rates because [Hint]
5.	In order for mutation rates to be subject to natural selection, they must meet Darwin's postulates. Correctly match each finding below with its corresponding postulate. [Hint] Using the pulldown boxes, match each item on the left to the corresponding item at right. A. Survival and reproduction are non-random. B. Variations among individuals are passed from parent to offspring. C. Individuals vary within populations Choice A Choice B Choice C Researchers have identified varying mutation rates in bacteriophages, E. coli, and other organisms.  [Hint] Choice A Choice B Choice C Specific mutations have been identified that change the efficiency of DNA synthesis and repair enzymes.  [Hint] Choice A Choice B Choice C E. coli cells with high mutation rates had higher fitness than normal cells when grown in novel environments.  [Hint]
6.	A growing body of literature suggests that mutations are surprisingly frequent on a per genome/per generation basis; most are _______ or ___________________. [Hint]
7.	In Denver et al.'s studies of the fitness effects of mutations on Caenorhabditis elegans, individuals in the control populations had higher fitness than did those in experimental populations. The best explanation for this result is that [Hint]
8.	The most important source of new genes is probably _____; the underlying mechanism for this is _____. [Hint]
9.	Evidence that the human hemoglobin gene family evolved via gene duplication includes [Hint]
10.	The most important evolutionary consequence of chromosomal inversions is [Hint]
11.	Polyploidy may result in a new species being formed in a single generation. For that to occur, which of the following conditions must exist? [Hint]
12.	Different versions of an enzyme, encoded by alleles at the same locus, are called . [Hint]
13.	A hypothetical population has two alleles for a gene, A and a. In a random sample of 50 individuals, 10 are homozygous for a, 15 are homozygous for A, and 25 are heterozygous. What is the frequency of A? [Hint]
14.	Two important measures of genetic diversity within populations are mean heterozygosity and the percentage of polymorphic loci. For each, give a brief definition and the general range of values found in natural populations. [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.
15.	The classical view of genetic diversity held that _____ genetic diversity was expected in most populations; this view has proven to be _____. [Hint]
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