AP BIOLOGY

Detailed explanation-1: -Ammonification of this nitrogenous waste by bacteria and fungi in the soil converts the organic nitrogen to ammonium ion-NH4 plus. Ammonium is converted to nitrit-NO2 minus-then to nitrate-NO3 minus-by nitrifying bacteria. Denitrifying bacteria convert the nitrate back into nitrogen gas, which reenters the atmosphere.

Detailed explanation-2: -As dead plants and animals decompose, nitrogen is converted into inorganic forms such as ammonium salts (NH4+) by a process called mineralization.

Detailed explanation-3: -Decomposition is a complex process. Organic matter is broken down into carbon dioxide and the mineral forms of nutrients like nitrogen. It is also converted into fungi and bacteria through these organisms feeding on the organic material and reproducing.

Detailed explanation-4: -Denitrification is the process that converts nitrate to nitrogen gas, thus removing bioavailable nitrogen and returning it to the atmosphere. Dinitrogen gas (N2) is the ultimate end product of denitrification, but other intermediate gaseous forms of nitrogen exist (Figure 7).

Detailed explanation-5: -Ammonification /Mineralization: In ammonification, bacteria or fungi convert the organic nitrogen from dead organisms back into ammonium (NH4+). Nitrification can also work on ammonium. It can either be cycled back into a plant usable form through nitrification or returned to the atmosphere through de-nitrification.