How do dolphins sleep if they must regularly come to the water's surface to breathe?
A) Only one brain hemisphere sleeps at a time.
B) Both hemispheres sleep at the same time but the sleep is light.
C) They retain air in their lungs and stay at the surface to breath while sleeping.
D) They do not come to the surface while sleeping, but instead obtain oxygen through their skin.

Question

Quizplus · Accepted Answer

Dolphins employ unihemispheric sleep, meaning that only one hemisphere of their brain sleeps at a time while the other remains awake to control essential functions such as rising to the surface to breathe. This allows them to rest while still being able to come up for air.

How Do Dolphins Sleep If They Must Regularly Come to the Water's