Question

Ambulacral system of echinoderms is mainly useful for
A. Locomotion
B. Feeding
C. Circulation
D. Defense

Answer 1

Hint: There are various systems in several types of organisms for execution of the basic functions needed for their survival. Water vascular system is one such system that starts in echinoderms (sea urchins, sea stars).

Complete answer:
> Option A:
An Ambulance system is also known as a water vascular system or hydraulic system or aquiferous system. It is a complex system which contains a pipe-like structure called canals. These canals are connecting links between several tube feet. It consists of a ring which is circumoral present in proximity to the esophagus which also shows canals that are radiating in nature and it performs locomotion through muscle contraction

> Option B:
Ambulacral parts consist of plates, spines, suckers and ossicles. An ambulacral groove is also found. It extends from the mouth to the terminal part of the arm and it performs various functions such as movement, transportation of food and various other products and exchange of gases.

> Option C:
These are organisms which live in sea water thus are marine animals. They are found on barrier reefs. They have many systems like digestive system, nervous system, circulatory system, etc.

> Option D:
Echinodermata circulatory system and nervous system is a basic system that circulates around its body. Their hemal system is environmentally open and allows for the exchange of gas through a series of channels throughout the body of the individual.

Hence, the correct answer is option (A).

Note: Echinodermata are named due to their special feature that is spiny skin. These are invertebrates and they exclusively live in sea water. They have a single body shape that can be circular, star formed, or cylinder like.