EVERYDAY SCIENCE

Detailed explanation-1: -Some sharks must swim constantly in order to keep oxygen-rich water flowing over their gills, but others are able to pass water through their respiratory system by a pumping motion of their pharynx. This allows them to rest on the sea floor and still breathe.

Detailed explanation-2: -The breathing process for sharks begins and ends with their gills, which they use to both extract oxygen from water and rid their bodies of carbon dioxide. Here’s the quick version of how it works, according to Sharkopedia: As water passes over the gills, small capillaries allow oxygen to enter the bloodstream.

Detailed explanation-3: -First, sharks lack the swim bladder that most fish use to adjust their buoyancy. Swimming creates lift that prevents sharks from sinking, using much the same principle that a wing uses to lift an airplane. Second, and more important, sharks, like other marine animals, get their oxygen from the water.

Detailed explanation-4: -Shark has to swim continuously, otherwise it will sink down. Give reason. Assertion: A shark can stay at a desired level in water without swimming. <br> Reason: Shark has a buoyancy regulating organ called as the swim bladder.

Detailed explanation-5: -Sharks do sleep in their restful period. Even at this period, they still have to swim because they need water to move over their gills. This helps them to breathe.