<span>The gland which signals other glands to secrete hormones is the pituitary gland.</span>
        
             
        
        
        
Answer: Plasmid.
A plasmid is a small DNA molecule within a bacteria cell that is separated from the chromosomal DNA and can replicate independently. Through Recombinant DNA, we can insert a gene that we want to see replicated in the plasmid, and when the bacteria multiplies, which it does often, we will obtain a lot of copies of  interest gene.
        
             
        
        
        
Domain is the most inclusive of the three, genus is the least inclusive
        
                    
             
        
        
        
Explanation:
To calculate the pH of an aqueous solution you need to know the concentration of the hydronium ion in moles per liter (molarity). The pH is then calculated using the expression: pH = - log [H3O+].