1- Discovery of DNA

All the scientists involved with different discoveries of DNA

Gregor Mendel

Pea plants: Consistent ratio in F1 and F2 generations

Hammerling

used one celled alga: Acetabularia

→ Excise cap, and it grew back b/c foot contained nucleus

→ took foot of med and stalk of cren > cap formed was med, so instructions for cap and directing cellular substance are in the nucleus!

Frederick Griffith

streptococcus pneumoniae s-strain and r-strain

heat killed s-strain had a non-living component that transformed r-strain into virulent s-stain bacteria

TRANSFORMATION PRINCIPLE

Avery, MacLeod, McCarty

Added protease, RNAse, DNAse to heat treated s-strain + r-strain. R-strain remained in the DNAse test tube: transformation occured

Hershey & Chase

Tagged (attached) viral proteins w Sulfide (radioactive)

Tagged DNA w Phosphur

P DNA entered bacterial cell (glowed)

Protein glowed on the outside

Wilkins and Franklin

x-ray crystallography

Rosalind took photo 51- DNA helical structure and sugar-phosphate backbone face out

Watson and Crick

Double Helix structure of DNA

Erwin Chargaff

Chargaff’s rations: Proportion of A=T & C=G