Amoeba: Respiration, Excretion

Respiration: There is no definite structure for respiration in Amoeba. Theyrespire through aerobic process. In absence of any definite organ, there respiration is accomplished by the plasmalema. Respiratory work mainly occurs through diffusion. The amount of dissolved oxygen of water where Amoeba lives is higher than the oxygen content of cytoplasm. As a result, oxygen can easily enter the body of Amoeba by diffusion process. Oxygen is required for respiration. To meet this requirement diffusion continuously occurs in the body of Amoeba. Carbon dioxide produced due to chemical reaction, is eliminated from the body in the same manner. This process can easily happen as the amount of carbon dioxide is more in the cytoplasm of Amoeba than in the water.

Excretion: The process by which the nitrogenous waste materials are collectedand removed from the animal body is called excretion. The excretory material of Amoeba is mainly ammonia. In dissolved condition these excretory materials are discharged outside through the plasmalema by the process of diffusion.