Question

Explain the breathing process of an :-
i) earthworm
ii) a fish
iii)a plant ​

Answer 1

Answer:

(i) Earthworms have no respiratory organ and hence the exchange of gases (respiration) takes place through the moist skin. The oxygen from the environment diffuses passively across the moist skin and it is carried by the circulatory system to the cells. Similarly carbon dioxide from the cells is also carried by circulatory system and diffused out through the moist skin. So they respire through their moist skin and will die if their skin dries out.

ii) In fishes respiration takes place through gills. When water flows through the gills the oxygen dissolved in water enters into the blood capillaries of the gills by diffusion. These capillaries then transport the oxygen throughout the body of the fish. The carbon dioxide that is released by the body cells is again transported by blood vessels to the gills. From there the carbon dioxide gets dissolved in flowing water and emitted out of the body.

iii) plants respire through the tiny pores on the surface of their leaves called stomata. Oxygen enters the plant, while carbon dioxide leaves the plant through these pores. This exchange of gases occurs through the process of diffusion. When carbon dioxide is present in high concentration inside the plant body, it moves out into the atmosphere (where its concentration is low) and allows oxygen to enter the plants.

The roots of plants also respire. They do so by taking in oxygen from the air spaces present in soil. This oxygen enters the root hairs through diffusion and then it reaches other cells of roots for respiration. Carbon dioxide produced during respiration move outside through the root hairs in the same way by the process of diffusion.

Explanation: