Chapter 6.1: Experimental Evidence for DNA as the Genetic Material

Question 1

What are nucleotides?

Answer 1

o The four individual DNA components belong to a class of compounds known as nucleotides

Question 2

What are phosphodiester bonds?

Answer 2

the bonds joining one nucleotide to another are covalent phosphodiester bonds

Question 3

What is a polymer?

Answer 3

the linked chain of building block subunits is a type of polymer

Question 4

How do bacteria divide?

Answer 4

binary fission

Question 5

What is transformation?

Answer 5

 The ability of a substance to change the genetic characteristics of an organism is known as transformation

Question 6

Describe the Hershey-Chase Warring Blender Experiment?

Answer 6

• T2 Phage
o Path 1:
 Infect E. coli and grow into 32P-containing medium
 Phages with 32P-labelled DNA
 Introduce phages into bacteria culture
 Blended briefly
 Radioactivity discovered in host and passed on to phage progeny
o Path 2:
 Infect E. coli and grow into 35S-containing medium
 Phages with 35S-labelled DNA
 Introduce phages into bacteria culture
 Blended briefly
 Radioactivity recovered in phage ghosts

Question 7

What was the outcome of the Hershey-Chase Warring Blender Experiment?

Answer 7

• Most of the radioactive 32P (in DNA) went to the pellet, while most of the radioactive 35S (in protein) remained in the supernatant
o This confirmed that the extracellular ghost were indeed mostly protein, while the injected viral material specifying production of more phages was mostly DNA