Lecture 5

Question 1

Order of 4 experiments leading to DNA info

Answer 1

1: Griffith
2: Avery
3: Hershey
4. Watson and Crick Paper

Question 2

Explain the Griffith experiment, also which number>?

Answer 2

number 1

A living Smooth strain would kill mice, a living r strain would not. Injecting a mouse with dead s strain and living r strain would kill mouse. Upon autopsy, living s-strain would be found in the heart, meaning the dead material was used to replicate.

Called the transforming principle

Question 3

Explain Avery experiment, also which number?

Answer 3

Number 2

The Avery experiment repeated the Griffith experiment, except also injected Proteases, RNAses, and DNAses.

Only the DNAses had an effect, which indicated the DNA material was responsible for the transforming principle.

Question 4

Explain Hershey and Chase Experiment, also which number?

Answer 4

Number 3

They wanted to test if it was DNA or Protein causing the transforming principle. So they added radioactive Phosphorus (which binds to DNA) and in a separate vial added radioactive Sulfur which binds to Proteins.

After centrifugation the P was found in pellet of the bacteria while the S was foind in the supernatant fluid indicating DNA, not protein, enters bacterial cells and directs the assembly of new viruses.

Question 5

Watson and crick number, what did they do?

Answer 5

PRoposed in a 1 page paper that DNA is a double helix. This was found to be the case. Also number 4

Question 6

Purines have __ rings and include:

Answer 6

2

A and G

Question 7

Pyrimidines have __ rings and include:

Answer 7

1

T and C

Question 8

T and A bonded form __ hydrogen bonds

Answer 8

2

Question 9

G and C bonded form __ hydrogen bonds

Answer 9

3