Contribution To Molecular Genetics

Question 1

Beadle and Tatum

Answer 1

1941

• bread mold (neurospora) experiment
• crossed potential mutants with non irradiated neurospora
• genes control metabolism

Question 2

Griffith

Answer 2

1928
-study pneumonia s=smooth r=rough 
Injected live strain in mouse 
-he understood that hereditary substance had passed from the dead s strain cells to live r cells. 
Called process transformation

Question 3

Meischer

Answer 3

1869

• WBC in puss infected bandage, found that he could precipitate nuclein
• nuclein is found in the nucleus
• has phosphorus and is acidic

Question 4

Avery, McCarty, MacLeod

Answer 4

1944

• grew streptococcus bacteria
• DNA is the transforming substance instead of proteins

Question 5

Hershey

Answer 5

1946
Did experiments on bacteriophage and ecoli
-used radio isotopes of sulphur and phosphorus
labelled protein wanted to know if protein causes changes to DNA
-concluded that DNA must be responsible for carrying genetic information

Question 6

Chargaff

Answer 6

1950
2 rules
-# of G and C same and # of A and T Same
-nucleotides do not repeat in same order

Question 7

Watson and Crick

Answer 7

1953

• DNA is double stranded helix
• DNA is anti parallel
• DNA pairs connect via H+ bonds

Question 8

Meselson and Stahl

Answer 8

1958

• semi conservative replication when DNA helix is replicated
• each of the two new double steamed DNA helixes consisted of one strand from the original helix and one newly synthesized