Nitrogen is released into the atmosphere when ________

A.

plants absorbs mineral salt

B.

sugar is completely broken down

C.

through plant uptake

D.

when lightning strike

Correct answer is D

Nitrogen is essential to all living systems, which makes the nitrogen cycle one of Earth's most important nutrient cycles.

Atmospheric nitrogen becomes part of living organisms in two ways. The first is through bacteria in the soil that form nitrates out of nitrogen in the air. The second is through lightning. During electrical storms, large amounts of nitrogen are oxidized and united with water to produce an acid that falls to Earth in rainfall and deposits nitrates in the soil.