It is on the organ level. The heart consists of cardiac muscle tissue and is part of the cardiovascular organ system. It is basic for the human body to work properly since it provides oxygen for the human body.
Answer:
Pollen grains land on the stigma and move down the pollen tube into the ovary.
Answer:
acetylcholinesterase breaks down Acetylcholine
Explanation:
enzyme acetylcholinesterase (AChE) breaks down Acetylcholine into it's inactive metabolites choline and acetate. This enzyme is highly efficient
