The vagina develops from the same embryonic tissue as the penis

Wakefulness is promoted by a(n)

a. histamine antagonist. b. norepinephrine antagonist. c. acetylcholine antagonist. d. histamine agonist. e. glycine agonist.

In males, which of the following is typically the first sign that a boy has entered puberty?

a. voice change b. appearance of pubic hair c. growth in the size of the testes and scrotum d. growth in the size of the penis