Question

The organs of locomotion in Echinodermata are
(a) Parapodia
(b) Pseudopodia
(c) Feet
(d) Tube feet

Answer 1

The phylum Echinodermata consists of free-living exclusively marine forms and thus bears locomotory apparatus that takes advantage of the immense energy of the ample water around them that systematically pushes the water inside out.

Complete answer:
The water vascular system is a hydraulic system that is used for locomotion, respiration, food, and waste transportation. It has canals which are connected to numerous tube feet to push the organisms against the ground and thus helping in locomotion. Tube feet are also known as the podium. The variation in the hydraulic pressure of the fluid in the canals helps the echinoderms to extend and retract their tube feet. The contraction of muscles also plays a role in this mechanism of locomotion.

Additional Information: -Pseudopodia are temporary extensions of the cytoplasm which protozoans like amoeba use for locomotion and movement.
-In annelids like Nereis, one pair of fleshy projections called the parapodia laterally emerges from all the segments except the first and the last segment. These unjointed locomotory apparatus of Nereis help them to swim.
-Feet are the terminal portions of hind limbs or legs in the humans which helps them to stand upright and also perform activities like walking, running and jumping, etc.
So, the correct answer is ‘Tube feet.’

Note: -The adults are radially symmetrical while their larvae are bilaterally symmetrical. Their body is represented by a central disc covered by ossicles with spines called pedicellariae. The disc also bears some extensions known as arms.
-Their digestive system is complete. They are mostly carnivores consisting of a mouth, oesophagus, two-part stomach, intestine, and rectum with anus located centrally.