Question

7. Which statement is correct?

1. Nitrogen must cycle through an ecosystem because it is used to make
proteins and nucleic acids.
2. Nitrogen makes up most of Earth's atmosphere.
3. Nitrogen gas from the atmosphere cannot be used by plants to make organic
compounds.
4. all of the above

Answer 1

4

Step-by-step explanation:

All statements presented are true.

Nitrogen is the main component in nucleic acids

Nitrogen is about 78% of the atmosphere

Nitrogen in the soil is the only way for plants to get nitrogen

Hope that helps