Answer:
C: autocrine
Explanation:
There are three types of hormones according to where their target cells are.
- Endocrine: Their target cells are distributed far and they travel via blood to reach the target cells.
- Paracrine: Their target cells are often their neighbors so they often diffuse to reach them
- Autocrine: Their secretion acts on themselves. Hence they are their own targets.
Because of photosynthesis
Answer:
The mass of a tree is primarily carbon.
Explanation:
The carbon comes from carbon dioxide used during photosynthesis.