Chapter 28, Problem 21A

Summary Introduction

Introduction:

Amphibians include toads, frogs, salamanders, newts, and legless caecilians. Most amphibians are distinguished by moist skin without scales, four legs, exchange of gases through skin, a circulatory system with double loop, lungs, and aquatic larvae.

Answer to Problem 21A

Correct answer:

The correct answer is option (B) B.

Explanation of Solution

Explanation/justification for the correct answer:

Option (B) B. The figure B is caecilians. Caecilians are legless and worm-like creatures. They burrow in the dirt, feed on worms and other invertebrates. Skin protects the eyes of many caecilians, and they may be almost blind. All caecilians have inner fertilization. So, the correct answer is option (B).

Explanation for incorrect answer:

Option (A) A. The figure A is Lizard. Lizards belong to reptiles. They have scaly skin, shelled egg, and more efficient circulatory and respiratory systems. So, this is an incorrect option.

Option (C) C. The figure C is a frog or toad. Frogs have longer and more powerful legs than toads that enabling them to jump. Frogs have moist smooth skin while the skins of toads are bumpy and dry. So, this is an incorrect answer.

Option (D) D. The figure D is a salamander. Salamanders have four legs and thin moist skin and cannot live far from water. So, this is an incorrect answer.