AP BIOLOGY

Detailed explanation-1: -Nitrogen is one of the primary nutrients critical for the survival of all living organisms. It is a necessary component of many biomolecules, including proteins, DNA, and chlorophyll.

Detailed explanation-2: -The nitrogen cycle matters because nitrogen is an essential nutrient for sustaining life on Earth. Nitrogen is a core component of amino acids, which are the building blocks of proteins, and of nucleic acids, which are the building blocks of genetic material (RNA and DNA).

Detailed explanation-3: -All living things need nitrogen to build proteins and other important body chemicals. However, most organisms, including plants, animals and fungi, cannot get the nitrogen they need from the atmospheric supply.

Detailed explanation-4: -Once nitrogen is converted into compounds like ammonium and nitrate, these can be taken up from soils by plants and then the nitrogen can be used to form macromolecules like proteins and nucleic acids (DNA and RNA).

Detailed explanation-5: -Nitrogen is an important element in DNA and proteins; however, atmospheric nitrogen is the only source of this element for life on Earth, and it cannot be absorbed by eukaryotes. As a result, nitrogen-fixing bacteria species, such as Rhizobia, live in a mutualistic relationship with plants like legumes.