Chapter 2, Problem 35A

Summary Introduction

To explain:

How the law of conservation of matter is related to the cycling of carbon in an ecosystem.

Introduction : Energy is transformed into usable forms to support the functions of ecosystem. So a constant supply of energy is needed for the biosphere but this is not true for matter. According to law of conservation of matter, matter can never be created nor destroyed. Therefore, natural processes cycle the matter through the biosphere. One such cycle is carbon cycle.

Answer to Problem 35A

During the carbon cycle, carbon gets converted into different compounds and are used first by one organism and then by another organism before being released into the atmosphere for recycling. The carbon atoms are neither created nor destroyed. They only change forms. Hence, the law of conservation of matter is followed by carbon cycle.

Explanation of Solution

During photosynthesis green plants and algae use carbon dioxide from the atmosphere to form carbohydrates and release oxygen back into air. The carbohydrates are used as source of energy by other organisms in the food web. This carbon dioxide is recycled when autotrophs and heterotrophs release it back in the air during respiration. The law of conservation of matter is followed by carbon through the cycle as carbon atom is neither created nor destroyed throughout the cycle. It simply changes form from one compound to another and enters different organisms. Finally, it gets released back to the atmosphere as carbon dioxide.