A forest of trees with white bark is home to a species of gray moth and to birds
which prey on them. Pollution made the bark of the trees go black. Several years later most of the moths found had wings that were
a) shorter.
b) longer.
c) lighter.
d) darker.

Acertain species of fish can have either long or short fins. the allele for long fins is dominant over the allele for short fins. a heterozygous, long-finned fish is crossed with a homozygous, short-finned fish. of the offspring, will have long fins and be , and will have short fins and be .