<span>The somatic nervous system is known as the voluntary nervous system, is a part of the peripheral nervous system. It consists of neurons that are associated with skeletal or striated muscle fibers. It affects voluntary signaling for many resion. A large part of the PNS is composed of 12 pairs of cranial nerves and 31 pairs of spinal nerves.</span>
It is a form of natural selection called sexual selection.
The correct answer is - They supply the energy needed for living processes.
Both the carbon and the nitrogen, are gases that are crucial for the survival of the organisms on the planet. They are mostly used by the producers in the ecosystems, as they need them to manage to perform their cycles, get nutrition, and of course energy. The producers are the basis of the ecosystems, so if they do not have a healthy supply of carbon and nitrogen, the ecosystems on the whole planet will collapse. The carbon and the nitrogen later go from one organism to another as the energy is transferred, and usually end up back into the atmosphere again.