Question

How does nitrogen in the atmosphere become beneficial to plants and eventually animals?

O Nitrogen must be mixed in the soil by earthworms,
O Nitrogen must be converted into a useful form by bacteria,
O Nitrogen must come in contact with decaying organic material,
O Nitrogen must come in contact with the ground through rainfall

Answer 1

O Nitrogen must be converted into a useful form by bacteria.

This bacteria is called the nitrogen fixing bacteria such as the Rhizobium bacteria.