Answer:
Nitrogen thet cannot be used by organisms. C.
Explanation:
Free nitrogen is simply molecular nitrogen (N2). Nitrogen, in its molecular form, consists of two nitrogen atoms bound together with a tripple bond. Because it is very stable, N2 is typically nonreactive, and takes a lot of energy to break them apart. Among these are the amino acids necessary for life to begin and which are the building blocks DNA is made from. Basically, any nitrogen that is in an organic compound is considered “fixed” nitrogen and N2 is considered to be “free” nitrogen
The retinas of night hunting animals have more rod cells which enable them to see better with minimum light.
The uterus relaxes is muscles after being stretched open. When the baby is about to be pushed out, the uterus contracts many times until the baby is out of the female's body.
It helps us survive. We can survive more time without food than without water
