DNA (1-5)

Frederic Griffith discovered transformation in his experiments on mice and Pneumococcus bacteria. He injected the mice with combinations of harmless,
R-strain bacteria and disease-causing S-strain bacteria. Which combination of bacteria killed the mice and showed that transformation occurred?

• heat-killed R-strain and live S-strain 

  
  

• heat-killed S-strain and live R-strain

• heat-killed bacteria of both strains

• live bacteria of both strains
  

Which statements describe a bacteriophage?

• It is a type of virus that infects bacteria.

• It is a type of bacteria that infects viruses.

• It is a virus consisting of a protein coat and a DNA core.

  
  

• A and C

The diagram illustrates the bacteriophages used in the Hershey-Chase experiment. What was the purpose of marking the bacteriophages with phosphorus-32 and sulfur-35?

• to track the movements of DNA and sugars

  
  

• to track the movements of DNA and proteins

  
  

• to remove DNA and sugars from the bacteriophages

• to combine DNA and proteins into a single molecule
  

What are the tasks that DNA must be able to perform in all organisms?

• It must store genetic information.

  
  

• It must instruct cells to produce needed molecules.

  
  

• It must copy itself.

  
  

• all of these

When does transformation occur?

• when an organism receives foreign RNA that is transformed into DNA

• when DNA is transformed into RNA

  
  

• when bacteria are killed with heat

  
  

• when a cell receives foreign DNA that is expressed as a new characteristic