Question

Locomotory organs in starfishes are:-
A. Parapodia
B. Pseudopodia
C. Suckers
D. Tube Feet

Answer 1

Hint:
Locomotory organs are analogous to legs with respect to human beings. Such organs help in flight in case of danger, movement from one place to another in search of food, or catching prey. Such structures, although present in a different shape or composed of different components perform these three basic functions.

Complete answer:
Parapodia is a locomotory organ but for annelids majorly. These appendages are merely extensions of the body placed laterally. These are usually dorso-ventrally flat. These can be found in pairs or unjoined and are filled with body coelom.
Pseudopodia are referred to as false feet as it has no definite structure but helps in locomotion. Usually found in amoeba, these stretch and contract in order to move. These are cytoplasmic extensions of the amoeba’s body.
Suckers are ‘devices’ found in flatworms that are used to attach to the host in order to feed on them or their food. These are usually found in internal organs where the proximity of finding food is more, near blood vessels, intestine et cetera.
Tube feet are long, slender structures found on the ventral/oral side of the echinoderms, especially starfish. These are known to be a part of their water vascular system as well. These are used as hooks as well. Other than that, these help in respiration and pass food to the mouth.
Thus, the correct answer is: Tube Feet

Option ‘D’ is correct

Note:
The water vascular system consists of an arrangement of canal-like structures in the body through which the water flows. Tube feet are an extension of such canals. Through hydraulic pressure, locomotion, respiration, circulation of food, and excreta are regulated.