Chapter 33, Problem 8STP

Summary Introduction

Introduction :

Many animals, including human beings, follow a routine cycle of behavior. This is called circadian rhythm, and it affects activities like sleeping and waking up that occur daily. This cycle is maintained by an internal biological clock that tells the body about changes in day and night on a daily basis and adjusts the sleep-wake cycle.

Answer to Problem 8STP

Correct answer :

The correct answer is option (c) just before dawn.

Explanation of Solution

Explanation/justification for the correct answer :

Option (c) just before dawn. Here, as per the graph, the minimum temperature is attained between 4-8 hours. So, the correct answer is option (c).

Explanation for incorrect answer :

Option (a) after eating. After eating, the body temperature rises very fast as per the graph. So, this is an incorrect option.

Option (b) in the afternoon. In the afternoon, the body temperature is at its peak. So, this is an incorrect answer.

Option (d) late at night. The body temperature starts to fall, but not to the minimum. So, this is an incorrect answer.