Chapter 8, Problem 7A

Summary Introduction

Introduction :

Heterotrophs are the organisms which do not make their own food but depend on autotrophs for the food. Autotrophs are those which make their food through photosynthesis using inorganic raw materials in the presence of light.

Answer to Problem 7A

Correct answer :

The correct answer is option (B) heterotrophs.

Explanation of Solution

Explanation/justification for the correct answer :

Option (B) the Sun. Heterotrophs are organisms which obtain food from autotrophs to obtain energy. Hence, they depend on autotrophs as an external source of organic compounds. Thus, this is the correct answer.

The explanation for the incorrect answer :

Option (A) photoautotrophs. Autotrophs convert energy from the Sun to make carbohydrate using carbon dioxide and water. So, they do not rely on an external source of organic compounds for energy. Thus, this is an incorrect answer.

Option (C) chemoautotroph. Some autotrophs that use inorganic substances such as hydrogen sulphide as a source of energy are called chemoautotroph. Thus, this is an incorrect option.

Option (D) Photoautotrophs. Autotrophs that convert energy from the Sun are called photoautotrophs. They do not rely on an external source of organic compounds for energy. Thus, this is an incorrect answer.