Question

Nitrogen is needed by plants for the manufacture of proteins.

• A. Coke
• B. Coal tar

Answer 1

The correct option is A

Coke

Some of the nitrogen compounds found in cells happen to be proteins.
By the action of specific bacteria, nitrogen gas - the principal component of air - is converted into soluble ions (nitrates) that plant roots can absorb.
In plants, these ions are then converted other important nitrogen compounds, which are absorbed by other organisms (which consume the plant) eventually. This way, the nitrogen content is passed from one organism to another. Eventually, the nitrogenous compounds are broken down and returned to the atmosphere as nitrogen gas. This is the nitrogen cycle.