Chapter 1, Problem 1A

Summary Introduction

Introduction:

Biology is a science (natural), which involves the living organisms and the study of their life-forms, chemical composition, physical structure, evolution, development and functioning. The living organisms respond to stimuli (internal and external), show growth and reproduction, adaptations, evolution and so on.

Answer to Problem 1A

Option (c) is given as “Living organisms respond to stimuli”.

The heart rate of humans increases, when the person is scared. This condition arises, when the living organism responds to the stimulus.

Hence, option (c) is correct.

Explanation of Solution

The biological science includes study of the organisms (living) and the environment in which they survive. There are certain characteristics that are common to all the organisms. One of the characteristics is that the living organisms respond to the stimulus. The living organisms respond to any external stimulus for maintaining homeostasis of the body.

Responding to a stimulus includes motion. Response to a stimulus can be either, by moving away from the stimulus or by moving towards it. The movement of humans is dependent on the musculoskeletal and the nervous system. Thus, response is a part of the human’s behavior.