Chapter 27, Problem 5A

Summary Introduction

Introduction:Echinoderms are deuterostomes which represent a significant transition in animal phylogeny. Echinoderms are aquatic mammals, and are the only species to have a deuterosome development and an endoskeleton in evolutionary history.

Answer to Problem 5A

Correct answer:

The correct answer is option (C) feeding, respiration, movement.

Explanation of Solution

Explanation/justification for the correct answer:

Option (C) is feeding, respiration, movement. Tube feet are short, flexible, fluid-filled tubes that end in suction-like structures and are used in walking, food collecting, and breathing.So, the correct answer is option (C).

Explanation for incorrect answer:

Option (A) isreproduction, feeding, and respiration. Most echinoderms perform sexual reproduction. The female shedding eggs and the males spilled sperm into water where fertilisation occurs. The fertilised eggs develop into bilateral symmetrical free-swimming larvae. Echinoderms use their tubular feet to feed and breathe. So, this is an incorrect answer.

Option (B) isfeeding, respiration, neutral control. Echinoderms feed and breathe through their tube feet. Echinoderms have sensory and motor nerves in various animals, of differing degrees of sophistication. In general, a nerve ring circles the mouth with branching nerve cords that connect to other areas of the body.So, this is an incorrect answer.

Option (D) is development, reproduction, respiration.An echinoderm is which regenerates a lost part of the body. Many echinoderms will drop an arm when attacked, allowing them to escape while distracting the predator.So, this is an incorrect answer.