Answer:
where is the picture? I can't help you without the picture...
 
        
             
        
        
        
Answer: a. Measuring the amount of rain that falls in a 24-hour period in a rain gauge.
 
        
             
        
        
        
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.
        
             
        
        
        
Answer:
Positive is the correct answer. 
Explanation: