It is apart of cellular DNA an ATP, and is a major component of bones and teeth, it is often only available in limited quantities in the the environment.
The second one I believe.
Answer:
The testes are responsible for making testosterone, the primary male sex hormone, and for producing sperm. Within the testes are coiled masses of tubes called seminiferous tubules. These tubules are responsible for producing the sperm cells through a process called spermatogenesis
Explanation:
its copied but hope it helps
If there were an interruption in the carbon cycle, life on Earth as we know it would be in danger of being disrupted. ... Without carbon dioxide, the plants would not do as well, and potentially die, creating a problem for all the animals on the planet, Since they have to breathe oxygen to live.