Question

Which statement best explains why some sea birds can drink seawater but humans cannot?

A. Their intestines are physically designed to filter salt from their diet.
B. Sea birds naturally have a higher intracellular osmolarity that requires excessive amounts of salt from their diet.
C. Salt glands secrete the excess salt.
D. Their nephrons are adapted to be longer to resorb less sodium to compensate for the excessive salt intake.
E. Specialized bacteria in sea bird's intestines utilize the salts before the sea bird can absorb them.

Answer 1

Sea birds can drink seawater because they have salt glands that secrete the excess salt, whereas humans lack these osmoregulatory mechanisms and cannot excrete salt as efficiently.

Step-by-step explanation:

The statement that best explains why some sea birds can drink seawater but humans cannot is C. Salt glands secrete the excess salt. Sea birds have specialized osmoregulatory mechanisms that allow them to handle the hypertonic environment of seawater. They have salt glands that actively excrete the excess salts they ingest when drinking seawater. These glands allow the sea birds to maintain their electrolyte balance despite the high salt concentration in their environment. In contrast, humans and many other animals do not have such mechanisms and would quickly become dehydrated due to the high salt content, as our kidneys can only produce urine that is less salty than seawater.