Answer:
b
Explanation:
the water gave the plant a drink
The circulatory system takes the carbon dioxide from the cells to the lungs and the respiratory system expels ir.
A single molecule is the one that is responsible for initiating a signal transduction pathway. The answer in this question is a single molecule. Molecule is defined as an electrically neutral group of two atoms or more held together by a chemical bonds.
You never put the answer choices so I can’t answer this question
