Question

An organism that can respire in the total absence of air is
A. Tapeworm
B. Earthworm
C. Amoeba
D. Hydra

Answer 1

Hint: Respiration in presence of oxygen is called aerobic respiration.ATP is produced. This type of respiration most commonly occurs in humans and plants. Another mode of respiration is anaerobic respiration occurring in absence of oxygen and the formation of less amount of energy. It mostly occurs in some bacteria.

Complete answer: Respiration in the total absence of air is called anaerobic respiration. It is breaking down food without oxygen. This type of respiration produces lactic acid, carbon dioxide, and less amount of energy than aerobic respiration. Tapeworm performs anaerobic respiration with the breakdown of sugar into lactic acid and ethanol. Less amount of energy is produced which is sufficient for tapeworms as they do not require large amounts of energy. Respiratory organs are absent in tapeworm.
-The earthworm performs aerobic respiration through its moist skin and that is why the skin of the earthworm remains moist. Oxygen enters and carbon dioxide releases out through the skin. Earthworms also have haemoglobin dissolved in the blood.
-Respiration in Amoeba occurs in the presence of oxygen. Hence it follows the aerobic mode of respiration. Oxygen gas from the surrounding enters through the cell membrane by simple diffusion and carbon dioxide is also removed by diffusion.
-Respiration in Hydra also occurs by diffusion through the epidermis surrounding the Hydra and carbon dioxide is also released in the same way. Hence hydra respire by aerobic mode of respiration.
Hence, the correct answer is Option A

Note: Tapeworm respire in absence of water and produce lactic acid, ethanol, and a very less amount of energy. Earthworms respire aerobically through their moist skin, Amoeba respires by diffusion through its cell membrane and Hydra also respires in presence of oxygen, and the exchange of gases occur through the epidermis.