Question

Amoeboid movement is a characteristic of Amoeba and human macrophages. It occurs when ectoplasm contracts to move endoplasm into pseudopodium. This contraction of the ectoplasm appears to be caused by
A. Sliding microtubules
B. Contracting microfilaments
C. Elongating cell walls
D. Changes in turgor pressure

Answer 1

Hint: Amoeba are widely distributed animals found in the bottom of mud or on the underside of aquatic vegetation in freshwater ponds, lakes, ditches, springs, pools, etc. Their body is covered by a thin plasma membrane called plasma lemma. It is differentiated into two zones- an outer ectoplasm and inner endoplasm.

Complete answer:
The cells show four types of movements:
Amoeboid movement is found in amoeboid protozoans, (example, Amoeba, Entamoeba), leucocytes of blood, phagocytes, macrophages, and slime molds. The movements in such cells are brought with the help of pseudopodia or false feet which are temporary finger-like cytoplasmic projections. So it is also called pseudopodial movements. These pseudopodia are formed by flow of cytoplasm, called cyclosis and cytoskeletal structure like microfilaments.
Ciliary movements are found in ciliated protozoans, e.g. Paramoecium Cilia are small-sized, fine, hair like structures and arise from cytoplasmic basal granules. These beat in coordination. Cilia are also present in certain internal structures of man and perform special functions, e.g. cilia lining the cells of ciliated epithelium of trachea, oviducts and vasa efferentia beat and move dust particles, eggs and sperms respectively.
Flagellar movements are found in flagellate protozoans, e.g. Euglena, dinoflagellates, flagellates. These are less in number but larger in size than cilia. These help in swimming of sperms and protozoans and maintenance of water currents in the canal system of sponges.
Muscular movements- These are brought about by the action of specific types of muscles.
So, the correct answer is “Option B”.

Note:
Movements of body parts and locomotion are two important properties of living organisms. The movements in the living organisms are autonomic in nature as the force is provided by the individual’s own body.