Question

How do humans obtain the nitrogen they use in their bodies?

1. by consuming plants or other animals
2. by absorbing ammonia from bacteria growing in the roots of plants
3. by breathing the nitrogen present in the atmosphere
4. by absorbing nitrogen found in the soil

Answer 1

While neither humans nor animals can get nitrogen into their bodies from the air or soil, they do gain nitrogen from vegetation or other animals which eat vegetation.

The answer is 1.

Answer 2

The correct answer would be 1. by consuming plants or other animals.

Humans are holozoic heterotrophs that is, they ingest food then digest it to get the required nutrition.

They get their nutrition by consuming other plants and animals such as wheat, pulses, chicken, meat, fish et cetera.

In humans, most of nitrogen is present in the form of protein which they get by consuming protein containing plants and animals.