Question

Why is nitrogen fixation important to all organisms?

It breaks down dead organisms.

It converts nitrogen gas into a usable form for plants.

It converts energy from the sun into a usable form for plants.

It produces much of Earth's oxygen.

Answer 1

It's because it converts nitrogen gas into a usable form for plants. Most organisms can't use nitrogen gas (N₂) as-is because it doesn't react easily with other compounds (due to the triple bond between the nitrogen atoms). Nitrogen has to be fixed (into ammonia (NH₃)) before it is accessible.