Aldosterone
a. increases blood sodium levels
b. decreases blood sodium levels
c. increases blood potassium levels
d. both b and c above

What initially causes a nerve impulse? release of enzymes out of the neuron movement of chemicals into the dendrites of the neuron pathogens attacking the dendrites of the neuron red blood cells bathing the neuron

Aristotle classified animals according to their a. habitat and mating behavior c. mating behavior and relatedness b. habitat and physical differences d. physical differences and mating behavior

How can you tell the difference between rough er from smooth er?