Consider the evolution of chordates, organisms with a hollow nerve chord. choose the organism most closely related to humans.
a) lamprey
b) sea star
c) lancelets
d) brittle star

Freckles are a dominant trait in humans. both of the girls have the genotype ff for freckles. if either one marries a man with no freckles, what are the chances that their children will have freckles?

Natural selection changes allele frequencies because some survive and reproduce more successfully than others.

The serengeti plains are part of the african savanna ecosystem and are home to a variety of different species of plants and animals. the serengeti plains experience a seven-month period of seasonal drought each year, during which the ecosystem receives only four inches of rain and the availability of some resources becomes very scarce. which type of limiting factors does the seasonal drought in the serengeti plains affect?