Question

Amoeba belongs to the class of
A. Ciliophora
B. Sarcodina
C. Mastigophora
D. Sporozoa

Answer 1

Hint:-Amoeba is an aquatic protozoa protist that lives at the bottom of fresh water pools, streams and on submerged objects. It is found in various habitats like in water with a lot of vegetation, decaying organic matter and bacteria.

Complete Answer:-
Amoeba belongs to the class of Sarcodina.
Sarcodines grow most commonly as free-floating or bottom dwellers in freshwater and seawater. Some of their forms are parasitic.
The body is without periplast. It may be naked or have a siliceous or calcareous shell. Mouth is absent and they are uninucleate, binucleate and multinucleate.
Amoeba :
They have a holistic mode of nutrition. Their body is irregular and asymmetric and it changes its shape due to the formation and withdrawal of finger-like pseudopodia. The cytoplasm is differentiated into peripheral ectoplasm and inner endoplasm. The endoplasm contains a biconvex nucleus, a spherical contractile vacuole, several food vacuoles and other cell organelles. It developed temporary protoplasmic outgrowths called pseudopodia which are finger-shaped, broad and blunt and help in locomotion and food capture. New pseudopodia are formed in the direction of movement while those of the other side are withdrawn so that the organism slowly creeps or flows over the substratum. Asexual reproduction occurs by binary fission and multiple fission or sporulation. Cyst formation takes place during the unfavorable conditions. No sexual reproduction has been reported till now.
Thus, the right option is B.

Note:- Protozoan parasites have worldwide distribution and may be aquatic, freshwater, terrestrial or parasitic. Parasitic forms cause serious diseases in humans and animals. Protozoan protists include four phyla- Zooflagellata, Sarcodina, Sporozoa and Ciliata.