Question

3. Which of the following statement is correct?

1 Plants can use nitrogen directly from the
air.
2 Rhizobium takes atmospheric nitrogen and converts it into soluble form.
3 Rhizobium makes its own food.
​

Answer 1

Answer:

1) Nitrogen fixation, the process by which nitrogen is converted to ammonia, is vital for plants to survive and grow. However, only a very small number of plants, most notably legumes (such as peas, beans and lentils) have the ability to fix nitrogen from the atmosphere with the help of nitrogen fixing bacteria.

2) Rhizobia are found in the soil and after infection, produce nodules in the legume where they fix nitrogen gas (N2) from the atmosphere turning it into a more readily useful form of nitrogen. From here, the nitrogen is exported from the nodules and used for growth in the legume.

3) Given that Rhizobium bacteria are not capable of making their own food for energy, they rely on the plant (in the rhizospere) to provide sources of energy.