No two people are genetically identical, except for identical twins. The main source of genetic variation among humans is
a. New mutations that occurred in the preceding generation.
b. Genetic drift.
c. The reshuffling of alleles in sexual reproduction.
d. Environmental effects.

Natural selection changes allele frequencies because some _________ survive and reproduce better than others.

a. Alleles

b. Loci

c. Species

d. Individuals

The largest unit within which gene flow can readily occur is a

a. Population.

b. Species.

c. Genus.

d. Hybrid.

How do the phospholipids in archaea differ from those in other cells?

a. They have tails made of unsaturated fatty acids instead of saturated fatty acids.

b. They do not contain hydrocarbon chains.

c. They have isoprenoid tails instead of fatty acid tails.

d. They have two hydrocarbon chains instead of three hydrocarbon chains.

What two functional groups are bound to the central carbon of every free amino acid monomer?

a. An R-group and a hydroxyl group

b. An N—H group and a (C═O) group

c. An amino group and a hydroxyl group

d. An amino group and a carboxyl group

Why isn't inbreeding considered an evolutionary process?

a. It does not change genotype frequencies.

b. It does not change allele frequencies.

c. It does not occur often enough to be important in evolution.

d. It does not violate the assumptions of the Hardy–Weinberg principle.

Why is genetic drift aptly named? Select True or False for each statement.

T/F It causes allele frequencies to drift up or down randomly.

T/F It occurs when alleles from one population drift into another.

T/F It occurs when mutations drift into a genome.

Which of these functional groups is known to be used for storing large amounts of chemical energy?

a. Amino group

b. Carbonyl group

c. Phosphate group

d. Sulfhydryl group