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Chapter 28: Q. 20 (page 776)

Echinoderms have _____.

a. triangular symmetry

b. radial symmetry

c. hexagonal symmetry

d. pentaradial symmetry

Short Answer

Expert verified

Option d is the correct answer.

Step by step solution

01

Introduction

One of the characteristics used to categorize animals is body symmetry. Animals can exhibit radial, asymmetrical, or bilateral shapes as the three types of body symmetries.

02

The explanation for the correct answer.

Although all echinoderms have bilateral symmetry in their early larval stages, adult echinoderms have pentaradial symmetry and a calcareous endoskeleton comprised of ossicles.

03

The explanation for the incorrect options.

The symmetry in which the organism is oriented longitudinally is known as radial symmetry. Any plane would produce mirror images in half if it were cut along this longitudinal axis. Echinoderms do not exhibit radial symmetry as larvae. Hexagonal and triangular shapes are not examples of body symmetry.

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Most popular questions from this chapter

Cnidocytes are found in _____.

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