Biology

The correct answer is:

A.We have no mechanism to break the triple bond of nitrogen between the atoms.

Explanation:

Nitrogen (N₂) in the atmosphere exists as a molecular nitrogen (N₂) gas, and the nitrogen atoms in N₂ are held together by a very strong triple bond. This bond is very difficult to break and requires specific enzymes and energy. Humans and most other animals do not have the biochemical machinery to break this bond and convert N₂ into a usable form of nitrogen like ammonia (NH₃) or nitrates (NO₃⁻).

Why the other options are not correct:

B.Our lungs would be damaged by the N₂ – This is incorrect because nitrogen gas is inert and does not harm the lungs in normal atmospheric concentrations. It's the lack of ability to use the nitrogen, not the nitrogen's toxicity, that is the issue.

C.We need Oxygen for cellular respiration – While this is true (we require oxygen for cellular respi...