Introduced an elegant double-helical model for the structure of DNA.

(Kidna stole it from the Franklin girl)

- worked with two strains of a bacterium, one pathogenic and one harmless

- Mixed heat-killed remains of the pathogenic strain with living cells of the harmless strain, some living cells became pathogenic.

- Announced that the transforming substance was DNA

- Conclusion was based on experimental evidence that only DNA worked in transforming harmless bacteria into pathogenic bacteria.

- Viruses that are widely used in molecular genetics research

- Helped further the study of DNA as a genetic material

- performed experiments showing that DNA is teh genetic material of a phage known as T2.

- Concluded that the injected DNA of the phage provides the genetic information

- Reported that DNA composition varies from one species to the next

- Chargaff's rule state that in any species there is an equal number of A and T bases, and an equal number of G and C bases

- Used a technique called X-ray crystallography to study molecular structure

- Franklin produced a picture of the DNA molecule using this technique

- Enabled Watcson to deduce that DNA was helical

- Enabled Watson to deduce teh width of the helix and the spacing of the nitrogenous bases

- T pairs up with A

- G pairs up with C

- Adenine and Guanine are double helicals

- Purine with a pyrimidine resulted in a uniform width consisten with the X-ray

- In DNA repication, the parent molecule unwinds, and two new daughter strands are built based on base-pairing rules