Question

Skeleton like function during locomotion of pheretima posthuma is performed by
A) Blood
B) Elementary canal laden with mud
C) Coelomic fluid
D) Ventral nerve cord

Answer 1

Hint:All living organisms like we, human beings can blend, jump, straight and walk exhibit movement which is one of their characteristic features. We must be aware that the moment in the plant is different from that in the animals. The simplest form of movement is protoplasmic streaming which is found in the unicellular organism such as amoeba. Besides the part of the body that helps in locomotion also help in other activities such as cilia in Paramecium help in movement of food through cytopharynx.

Complete answer:
A skeleton-like function during locomotion of pheretima posthuma is performed by the movement of the coelomic fluid. The coelomic fluid acts as a skeleton which allows the earthworm to move forward and backward. The locomotion is brought about by the increase in the hydrostatic pressure of the interior ten segments. There is a contraction of the circular muscles which begins at the interior and the wave passes backward. This causes the anterior region to extend. The anterior end grips and seat acts as anchors on the soil. Then, the circular muscles relax, and longitudinal muscles of the anterior segments contract in a wave beginning from the anterior and which shortens the anterior Indian causes the posterior part of the body to pull forward. These moments of contraction and relaxation result in the locomotory movement. The coelomic fluid serves as a hydraulic skeleton and seat causes the body to anchor firmly in the soil.

Hence the correct answer is option ‘C’.

Note:Animals need to perform locomotion for various reasons including for the search of food, mating, shelter, breeding ground and favourable Climatic condition and safety from predators or enemies. Therefore, the different methods of locomotion that animals perform depend upon their habits and demand of the situation.