McGraw-Hill Online Learning Center Test<BLURT>

McGraw-Hill Online Learning Center Test

1. Review the animation and answer the following questions.

The molecular clock is based on the finding that

A. all mutations are either advantageous of disadvantageous to the organism.
B. new species have evolved at a uniform rate throughout evolutionary time.
C. genetic differences accumulate at a fairly constant rate.
D. all mutations are neutral to selection.

2. Divergence is necessary for all of the following EXCEPT A. speciation.
B. the accumulation of different random mutations in the genes of two species.
C. the use of the molecular clock.
D. the accumulation of random mutations in the DNA.

3. Evolutionary biologists have found that different genes accumulate changes at different rates but that the rate for a particular gene is constant among different organisms. This is because A. the DNA of some organisms mutates faster than the DNA of other organisms.
B. certain genes (and therefore certain gene products) can tolerate more mutations than others.
C. certain stretches of DNA are more likely to undergo mutations than others.
D. there are periods of very few mutations followed by periods of rapid mutation.

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