Question

Observe fish in an aquarium. You will find flap like structures on both sides of their heads. These are flaps which cover the gills. These flaps open and close alternately. On the basis of these observations, explain the process of respiration in the fish.

Answer 1

When observing fish in an aquarium, you will notice flap-like structures on both sides of their heads. These flaps, called opercula, cover the gills and open and close alternately. The process of respiration in fish can be explained as follows:

1. Water Intake: Fish open their mouths to take in water.
2. Passing Over Gills: Water flows over the gills, where oxygen is absorbed into the bloodstream and carbon dioxide is expelled from the blood into the water.
3. Opercula Movement: The opercula (flaps) open to allow water to exit the gill chambers after the gas exchange, then close to facilitate the continuous flow of water over the gills.

Explanation: This alternating movement of the opercula ensures that fresh, oxygen-rich water continuously passes over the gills, enabling efficient gas exchange necessary for fish respiration.