Chapter 18, Problem 16STP

Summary Introduction

To describe:

Benefits that rhizobium and plants gets from their mutual relationship.

Introduction:

Plants are autotrophs and like other living things they also need variety of nutrients for their survival. They can synthesize their own food, but they obtain many nutrients from the soil and the atmosphere.

Explanation of Solution

The beans are leguminous plants, which have the properties of nitrogen fixation. The root of these plants has association with rhizobium bacteria. These bacteria fix the atmospheric nitrogen into the soil, which makes soil nitrogen rich and provides a better growth atmosphere for the other plants. Hence, these plants help in replenishing the nutrients.

In return of the nitrogen fixation, the bacteria acquire its nutrient from the plant. The bacteria cannot synthesize the organic acids, so, plant act as a source of organic acids such as succinate, malate and dicarboxylic acids.