10

47) Which of the following can evolve? 
 A) 

Individuals 

 B) 

Populations 

 C) 

Genes 

 D) 

DNA 

E) All of the above 

 
48) Genetic variations in natural populations develop due to: 
          A) Random mutations of the DNA 
 

B) Changes in the diet 

C) Changes in the environment 

D) Environmental catastrophes 

E) Individual activities 

 
49) An antibiotic is given repeatedly to treat a recurrent ear infection. It worked  
       initially but now is no longer effective. This likely indicates that the  
      

Streptococcus  

bacterium: 

A) Is very sensitive to the antibiotic. 

B) Is being treated with an antibiotic that has experienced a manufacturing  

     error, making it ineffective. 

C) Experienced natural selection that has allowed the resistant  

Streptococcus

  bacteria to survive and multiply. 

D) Are infectious only if they are sensitive to the antibiotic. 

E) All of the above 

 
50) Natural selection can act on a trait only if the trait is: 
          A) Heritable 
 B) 

Behavioral 

 C) 

Favorable 

 D) 

New 

 E) 

Morphological