The cycle that involves the conversion of nitrogen gas into a usable form by bacteria is the:
a.
carbon cycle
b.
nitrogen cycle
c.
water cycled.
d.
none of the above

Where is energy trapped inside the organelle chlorophyll

Pepsin is an enzyme in the stomach that breaks polypeptides into amino acids. pepsin functions best at a ph of around 1.5. what would be the most likely result if the ph of the stomach were increased to 5

What percentage of light hits earth's surface directly?