Author Question: A transport mechanism that can move a substance against a concentration gradient by using cellular ... (Read 29 times)

nautica902 · **on:** Feb 27, 2019

A transport mechanism that can move a substance against a concentration gradient by using cellular energy is
A) simple diffusion.
B) facilitated diffusion.
C) osmosis.
D) bulk transport.
E) active transport.

Question 2

Contractions of the papillary muscles
A) close the atrioventricular valves.
B) close the semilunar valves.
C) eject blood from the ventricles.
D) prevent the atrioventricular valves from reversing into the atria.
E) eject blood from the atria into the ventricles.