Chapter 7, Problem 1MCQ

The source of the necessary elements of life is

1. a. an inorganic environmental reservoir.
2. b. the sun.
3. c. rocks.
4. d. the air.

Summary Introduction

Introduction:

The essential elements are acquired by all living beings in their basic forms as nutrients from their inorganic reservoirs in the environment. These reservoirs of elements are constantly recycled by the organisms, so they are a permanent source of elements. The compounds found in these reservoirs can contain more than one element.

Answer to Problem 1MCQ

Correct answer:

The source of essential elements of lifeis an inorganic environmental reservoir. Therefore, option (a) is correct.

Option (a) is given as “An inorganic environmental reservoir”.

Explanation of Solution

Justify reasons for the correct statement:

An organic environment reservoirisa permanent source of elements.

Hence, option (a) is correct.

Justify reasons for the incorrect statements:

Option (b) is given as “the sun”.

Sun is the ultimate source of energy. Hence, it is a wrong answer.

Option (c) is given as “rocks”.

Rocks are the reservoir of minerals. Hence, it is a wrong answer.

Option (d) is given as “the air”.

Air is the source of essential gases required for survival like oxygen. Hence, it is a wrong answer.

Hence, options (b),(c), and(d) are incorrect.

Conclusion

The inorganic environmental reservoirs are the only source of essential elements that are acquired by living beings in the form of nutrients. Sun, air,and rocks are not the sources of these elements.