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46) A human male has ___ chromosomes with ___ sex chromosomes. 
          A) 46, XY 
 

B) 48, XY 

C) 46, XX 

D) 48, XX 

E) 48, YY 

 
47) Which statement is NOT true about x-linked characteristics? 
          A) More males than females are affected 
 

B) If a female has the characteristic, all her sons will show it 

C) Females can be carriers of the gene without showing it 

D) The characteristic often skips a generation, from a woman’s father 

      to her son 

E) Males can have two copies of the allele for the trait, but females only 

              have one 
 
48) Which organism is 

least likely

 to survive to reproduce? 

A) A flower that produces a scent that attracts bees 

                                    B) A shrub that produces a toxin in its flower buds that repels deer 
                                  C) An animal with a mutation that causes skin color to be more noticeable 

              D) A dark-furred rodent that comes out only at night 

             E) a seahorse that mimics the weeds in which it lives 

49) Evolution: 
 

A) Occurs too slowly to be observed 

B) Can occur in the wild but not in the laboratory 

C) Is responsibility for the increased occurrence of antibiotic-resistant  

     bacteria 

D) Is unrelated to mutations in DNA 

E) All of the above are correct 

 
50) Which mutation provides a survival advantage? 
          A) A flower that attracts more bees 
 

B) A tree that grows shorter than the surrounding trees 

C) A horse that lacks the ability to digest either grains or grass 

D) A brightly colored fish that attracts predators 

E) A shrub that loses the ability to make seeds