Lecture 3

Question 1

Griffith

Answer 1

1928: chromosomes carry genetic information and DNA and protein // don’t know which one holds genetic material
* S and R cells injected.
* can conclude:
(1) DNA from heat killed S cells made live R cells virulent
(2) live r cells activated virulence of heat killed s cells ??

Question 2

Oswald

Answer 2

Ruled out that polysaccharides and lipids contain genetic material
From s strain, he killed only polysaccharides, lipids, RNA, protein, and DNA
Virulent s cell when injected with destroyed DNA let rat live all others meant rat died

Question 3

Hershel

Answer 3

Labelled phage with phosphorous DNA and sulfur protein capsule
Only the phage with DNA radioactive showed that DNA holds genetic material

Question 4

Watson Crick

Answer 4

They knew about
(1) components and structure of DNA
- deoxyribose sugar, nitrogenous base, phosphate group
- 5’ - 3’ direction
- {phosphate on the 5” end
- antiparallel
phosoate gives energy to add nucleotides and prevents nucleotides on 5 end