Answer:
Human, nervous system, nerve tissue, neurons.
Explanation:
The organism is the biggest, in this case is a human, a human is composed of systems, and then organ tissue, and organ tissue is made out of cells.
 
        
                    
             
        
        
        
Answer:
Complementary base pairing
Explanation:
DNA probes are the single stranded stretches of nucleotides that are complementary to the original strand. DNA probes are used in various molecular technologies like polymerase chain reaction and DNA finger printing.
DNA probes can only hybridize with the specific complementary base pairs. Hence, complementary base pairing determines the specificity of DNA probe.
Thus, the correct answer is option (D). 
 
        
                    
             
        
        
        
Answer: Survival of Aquatic Organisms
Explanation: The deepest layer is the cold, dense water at the lake bottom, called the hypolimnion, it is important for all the aquatic organisms in a lake that require oxygen to survive.