A stalked, sessile marine organism has several feathery feeding structures surrounding an opening through which food enters. The organism could potentially be a cnidarian, a lophophorate, a tube-dwelling worm, a crustacean, or an echinoderm. Which of the following traits, if found in this organism, would allow the greatest certainty of identification?
A) the presence of what seems to be radial symmetry
B) a hard covering made partly of calcium carbonate
C) a digestive system with mouth and anus separate from each other
D) a water vascular system
E) a nervous system

Question

Quizplus · Accepted Answer

A water vascular system is a unique feature of echinoderms, such as starfish and sea urchins, which aids in locomotion, feeding, and respiration. This characteristic would allow for the most definitive identification among the options provided.

A Stalked, Sessile Marine Organism Has Several Feathery Feeding Structures