Chapter 28, Problem 23A

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 23A

Correct answer:

The correct answer is option (C) kidneys.

Explanation of Solution

Explanation/justification for the correct answer:

Option (C) kidneys. Amphibians filter wastes from the blood through their kidneys and excrete either ammonia or urea as the waste product of cellular metabolism. Thus, amphibians use to maintain homeostatic water balance by using their kidneys. So, the correct answer is option (C).

Explanation for incorrect answer:

Option (A) nictitating membranes. For most amphibians, vision is an essential feature. They use sight to find and catch the prey that is traveling at high speeds and to avoid predators. Frog's eyes have structures called nictitating membranes. The nictitating membrane is a translucent eyelid that can pass around the eye to shield it underwater and prevent it from drying out on the land. So, this is an incorrect option.

Option (B) tympanic membranes. The tympanic membrane is an eardrum. In frogs, it is a thin outer membrane on the side of the head. Frogs use their tympanic membrane to hear high pitched sounds and to amplify sounds from the vocal cords. So, this is an incorrect answer.

Option (D) swim bladders. Amphibians have swim bladders. Swim bladders are balloon-like organs that are filled with oxygen and other gasses from the bloodstream. This helps them to float in the sea. So, this is an incorrect answer.