Chapter 3, Problem 4STP

Summary Introduction

Introduction :

The biosphere consists of all the ecosystems present on the earth. There are many biogeochemical cycles that is helpful in recycling of the nutrients in the biosphere.

Answer to Problem 4STP

Correct answer :

Option (a) breakdown of the organic material by the decomposers.

Explanation of Solution

Explanation/justification for the correct answer :

Option (a) breakdown of the organic material by the decomposers. The breakdown of the organic material into simpler compounds by decomposers provide the nutrient for the plants to grow. The decomposition ensures the movement of the material in the biosphere.

Explanation for incorrect answer :

Option (b) formation and weathering of rocks. The formation and weathering of rocks is not a long term nutrient cycling process, as rocks are not a source of nutrition. Hence, it is an incorrect answer.

Option (c) formation of compound used for food by living organism. This is a part of nutrient cycling, but its short term process. Hence, it is an incorrect answer.

Option (d) movement of fresh water from land to the water bodies through runoff. It is not apart of long term nutrient cycling. Hence, it is an incorrect answer.