AP BIOLOGY

Detailed explanation-1: -Fixation: In order for organisms to use atmospheric nitrogen (N2), it must be “fixed” or converted into ammonia (NH3). This can happen occasionally through a lightning strike, but the bulk of nitrogen fixation is done by free living or symbiotic bacteria.

Detailed explanation-2: -During lightning, the atmospheric nitrogen reacts with oxygen present in the atmosphere to form Nitric acid which comes down to the earth with rainwater and reacts with water to form nitrates that are absorbed by plants.

Detailed explanation-3: -A small amount of nitrogen can be fixed when lightning provides the energy needed for N2 to react with oxygen, producing nitrogen oxide, NO, and nitrogen dioxide, NO2. These forms of nitrogen then enter soils through rain or snow. Nitrogen can also be fixed through the industrial process that creates fertilizer.

Detailed explanation-4: -Atmospheric fixation: A natural phenomenon where the energy of lightning breaks the nitrogen into nitrogen oxides, which are then used by plants.