The tube feet in echinoderms are extended by forcing water into them from the
A) madreporite.
B) ring canal.
C) radial canal.
D) ampullae.
E) mouth.

Question

Quizplus · Accepted Answer

The tube feet in echinoderms are extended by forcing water into them from the ampullae. The ampullae are muscular sacs that contract to push water into the tube feet, causing them to extend. This is part of the water vascular system unique to echinoderms, such as starfish and sea urchins, which facilitates movement, feeding, and gas exchange.

The Tube Feet in Echinoderms Are Extended by Forcing Water