The end of the Miocene brought what to Africa?

A) drop in temperature
B) reduced rainfall
C) increased food supply
D) a and b
E) a and c

Which of the following is the largest group of hormones?

A) Steroid hormones
B) Polysaccharide hormones
C) Amino acid derivatives
D) Peptide hormones
E) Fatty acid derivatives

During which stage do cells of identical genetic makeup become structurally and functionally different from one another according to the genetically controlled developmental program of the species?

A) cleavage
B) cell differentiation
C) morphogenesis
D) metamorphosis
E) ovulation

A mass of undifferentiated plant cells is called a callus.

If five action potentials arrive at the same synapse in very close succession, which of the following would occur?

A) The direction of the action potential is reversed.
B) Temporal summation occurs.
C) Spatial summation occurs.
D) Hyperpolarization occurs.
E) Depolarization always occurs.

Consider the statement "biological systems interact." What does this mean?

A) Systems combine to reproduce.
B) Biological organisms are interdependent.
C) Structure and function are not interrelated.
D) Biological organisms are not interdependent.
E) Every organism is in conflict with other organisms.