Question

Which of the statements describes how marine fish maintain osmotic balance?

A) They maintain body fluid solute concentrations that are higher than that of the surrounding water.

B) Chloride cells in the gills actively pump chloride ions into the body.

C) They tend to gain water through osmosis.

D) They drink water to replenish water supplies.

E) They are osmoregulators.

Answer 1

B) Chloride cells in the gills actively pump chloride ions into the body is the statement that describes how marine fish maintain osmotic balance.

Marine fish live in a hypertonic environment, which means that the solute concentration of seawater is higher than that of their body fluids. To maintain osmotic balance, marine fish have specialized cells called chloride cells in their gills that actively pump chloride ions into the body. This process helps the fish to excrete excess salts and maintain a balance of solutes in their body fluids.

Option A is incorrect because marine fish actually maintain body fluid solute concentrations that are lower than that of the surrounding water.

Option C is also incorrect because marine fish tend to lose water through osmosis, not gain it.

Option D is incorrect because marine fish do not drink water as a means of replenishing their water supply.

Option E is also incorrect because marine fish are not osmoregulators; they are actually osmoconformers, meaning that their body fluids match the salinity of the surrounding seawater.