Question

Some sharks and tunas possess a ________, a blood circulation system that allows them to keep internal temperatures higher than external temperatures.

Answer 1

Sharks and tunas possess a countercurrent heat exchange system that allows them to keep their internal temperatures higher than external temperatures.

Step-by-step explanation:

Sharks and tunas possess a countercurrent heat exchange system that allows them to keep internal temperatures higher than external temperatures.

This mechanism involves the transfer of heat from arteries to veins through closely aligned blood vessels, which helps warm the cold venous blood before it reaches the heart and other internal organs.

This adaptation enables these animals to thrive in cold environments.