Why is Nitrogen Fixation an Essential Process

Question

Why is nitrogen fixation an essential process?
A) Nitrogen fixation can only be done by certain prokaryotes.
B) Fixed nitrogen is often the limiting factor in plant growth.
C) Nitrogen fixation is very expensive in terms of metabolic energy.
D) Nitrogen fixers are sometimes symbiotic with legumes.
E) Nitrogen-fixing capacity can be genetically engineered.

Accepted Answer

Fixed nitrogen is often the limiting factor in plant growth, as plants require nitrogen to build proteins, nucleic acids, and other essential cellular components. Nitrogen gas, which makes up 78% of the Earth's atmosphere, cannot be directly used by most plants, so they rely on fixed nitrogen sources such as protein-rich soil, fertilizers, or nitrogen-fixing bacteria. Without nitrogen fixation, plant growth and biomass production would be severely limited, which would have cascading effects throughout ecosystems.