Question

A marine bony fish must continuously

• A. Acquire water and get rid of salt
• B. Get rid of both water and salt
• C. Get rid of water and acquire salt
• D. Acquire both water and salt

Answer 1

The correct option is A Acquire water and get rid of salt

Water naturally seeks a chemical balance, or equilibrium. That means water flows from areas of higher water concentration to areas of lower water concentration to equalize the system. Water concentration inside a fish is higher than in the ocean itself because the ocean is so salty. As a result, most saltwater fish constantly lose water through their gills and skin. Because the fish is losing water, it must drink a lot to stay hydrated-but salty seawater is the only water around. To get rid of excess salt, the fish's kidneys pump lots of salt into its urine.

Hence the correct option is A.