Answer:
 b. pieces of DNA is the correct answer.
Explanation:
A gene is a piece of DNA and it is present in the nucleus of all cell's 
The function of the gene is to codes for a specific type of protein.
Genes convey the message that determines our characteristics
Genes are called as a functional unit of genetics.
 
        
             
        
        
        
The cardiovascular system I think. Hope this helps
        
                    
             
        
        
        
Population........................................................................
        
             
        
        
        
They don't use common names because the want other scientist to know what their talking about.∞
        
             
        
        
        
Answer:
Gene expression is the process by which the information encoded in a gene is used to direct the assembly of a protein molecule. The cell reads the sequence of the gene in groups of three bases.
Explanation: