Chapter 42, Problem 2TYK

Summary Introduction

Introduction:

The terrestrial animals exchange gases with the help of lungs and carry out air breathing. However, in the aquatic animals, the exchange of the gases occurs in the water. Water breathing is difficult than breathing in the air. This is because $P_{{\text{O}}_2}$ (partial pressure of oxygen) within water is very less than $P_{{\text{O}}_2}$ in the air. Air breathing also has some disadvantages.