A

Edwin Chargaff

James Watson & Francis Crick

1949

1953

discovers the base-pairing rules of the nitrogenous bases

finalize the structural model of DNA after getting a preview of the x-ray diffraction photo

A-T and G-C

Rosalind Franklin &

Maurice Wilkins

1952

realize that the DNA model was a helix after doing X-ray diffraction

P

Hydrogen Bonds

Covalent Bond

D

T

A

Nitrogenous Bases

P

C

G

D

Phosphate

P

Nucleotide

Deoxyribose