Exam 25: The History of Life on Earth

If natural selection in a particular environment favored genetic systems that permitted the production of daughter "cells" that were genetically dissimilar from the mother "cells," then one should expect selection for which of the following? I. polynucleotide polymerase with low mismatch error rates II. polynucleotide polymerases without proofreading capability III. batteries of efficient polynucleotide repair enzymes IV. polynucleotide polymerases with proofreading capability V. polynucleotide polymerases with high mismatch error rates

The hypothesis for the origin of eukaryotes through serial endosymbiosis proposes that

How many of the following statements concerning the loss of hind limbs during whale evolution are true? 1. It is well documented by a series of transitional fossils. 2. It explains why modern whales have vestigial pelvic girdles. 3. It involved changes in the sequence or expression of Hox genes. 4. It is an example of macroevolution. 5. It, and the loss of limbs by snakes, are examples of similar adaptations to a similar environment.