99% of calcium is found inside the cells of the body.
Ecosystems can be large and are made of biomes. Some examples of ecosystems are deserts and forests.
Answer: A.) The nitrogen cycle recycles nitrogen through an ecosystem, making it available to all organisms.
Explanation: Nitrogen is an essential nutrient for plants and a significant component of proteins, which all animals need to grow, reproduce and survive. The nitrogen cycle converts nitrogen into compounds that plants and animals can use.
A - Viruses cannot survive outside of a host whereas bacteria can.