Answer:
The atmosphere is the largest reservoir of the nitrogen as it is composed of 78% of Nitrogen. Although 78%, this is not used by the organisms directly as the nitrogen molecule exists in nature in the form of divalent joined via triple bonds.
These triple bonds require a great amount of energy to be broken and used. Only a few prokaryotic organisms called nitrogen-fixing bacteria have the capability to break these triple bonds as they contain enzymes-nitrogenase complex which converts the atmospheric nitrogen to usable forms like ammonia, nitrates and nitrites. About 92% of the atmospheric nitrogen is fixed through this way rest through thunderstorms and Haber's process.
Thus, nitrogen-fixing bacteria is the answer.
Multiple species aka animals, humans, plants and all the species interactions :)
Answer:
A. motor neurons; peripheral nervous system
Explanation:
Motor neurons carry signals from the peripheral nervous system to the muscles. This causes the muscles to either relax or contract. Note that the peripheral nervous system consists of neurons and parts of neurons outside of the central nervous system which consists of the brain and spinal cord. When signals are transmitted between the motor neurons and peripheral nervous system, this causes a response to stimulus in the muscles which would either, relax or contract.
