The lymphoid tissues that trap and remove bacteria that enter the throat are indicated by ________

Opening of sodium channels in the axon membrane causes

A) depolarization. B) repolarization. C) hyperpolarization. D) increased negative charge inside the membrane. E) inhibition.

What do nicotinic receptors bind?

A. Epinephrine B. Norepinephrine C. Dopamine D. Acetylcholinesterase E. Acetylcholine

The inner cell mass of the blastocyst

A. contains cells that will form the embryo. B. contains cells that are discarded. C. consists of yolk-filled storage cells. D. represents the future placenta. E. will form the zona pellucida.

The gonads, adrenal cortex, and posterior pituitary gland secrete steroid hormones.

a. true b. false