Question

Which is not the locomotory organ of protozoa?
A) Cilia
B) Flagella
C) Pseudopodia
D) Parapodia

Answer 1

Hint:Different organisms have different arrangements of body that involve in the movement of the organisms. The cilia and flagella also comprise of special microtubule arrangement that support them during mobility.

Complete answer:
To answer this question, we first understand about the locomotion of protozoans. The protozoan shows four types of locomotion process; pseudopodia, flagellated, ciliary, and peristaltic movement. The pseudopodial are fingerlike and blunt protrusions of cytoplasm that help in protozoan movement. Amoeba shows pseudopodium movement also termed as lobo podium. The pseudopodium is attached with the help of adhesive production and protoplasm of the body. The flagellate movement is carried out with the help of flagella. Flagella are a whip –like structure found in some protozoans. They are found in 2-4 in numbers and are made up of a stiff structure called axoneme that is found around the protoplasmic sheath. Euglena shows the flagellate movement from a single flagellum that is present in the anterior end of the body and considered as tractellum. Ciliary movement is the movement of a protozoan with the help of cilia. Cilia are a hair-like structure found in a very large number in the body of some protozoan. The paramecium shows ciliary movement in a rotating manner by the beating movement of cilia. They are small oars that push the organisms forward. The peristaltic movement is observed in some of the protozoan that means the movement with the help of myonemes. Myonemes are thread-like fibrils structure found in the inner layer of the ectoplasm. The contraction of the fibrils is used for the contraction of pellicle so that the organisms can move in a jerking direction.
Now, parapodia are the parallel feet that are found in annelids. Such a locomotion process is not found in protozoans.

Thus, the correct answer is option ‘D’. Parapodia.

Note: The axoneme is the fibrillar bundles usually consisting of nine pairs of microtubules arranged and from a ring like structure around the single central pair. It forms the core of a cilia and flagella and is involved in providing motility to the organisms.