AP BIOLOGY

Detailed explanation-1: -Nitrogen assimilation is the formation of organic nitrogen compounds like amino acids from inorganic nitrogen compounds present in the environment. Organisms like plants, fungi and certain bacteria that cannot fix nitrogen gas (N2) depend on the ability to assimilate nitrate or ammonia for their needs.

Detailed explanation-2: -Nitrogen fixation is the processes by which atmospheric N2 is converted to any N compound where N has a nonzero oxidation state. Historically, the most common process has been the biologically driven reduction of N2 to NH3 or NH4+.

Detailed explanation-3: -Fixation. Nitrogen in its gaseous form (N2) can’t be used by most living things. (Plants for example, do not have the required enzymes to make use of atmospheric nitrogen.) It has to be converted or ‘fixed’ to a more usable form through a process called fixation.

Detailed explanation-4: -nitrogen fixation, any natural or industrial process that causes free nitrogen (N2), which is a relatively inert gas plentiful in air, to combine chemically with other elements to form more-reactive nitrogen compounds such as ammonia, nitrates, or nitrites.

Detailed explanation-5: -(b) Nitrogen fixation: The nitrogen from the atmosphere can be utilized by certain microbes by the biological fixation method. The microbes alone or in a symbiotic relationship with some plants and animals can fix atmospheric nitrogen. Thus, the correct answer is option B. Was this answer helpful?