The amount of certain bases always occurred in a one-to-one ratio.
Nitrogen bases always match up like this:
Adenine Ė Thymine and Cytosine -- Guanine
Using X-ray techniques took pictures of DNA and discovered the double helix shape of DNA.
Died of cancer due to unknown harmful affects of X-ray
First scientists to create a model of DNA
It is still the model used today
Sides are made of sugar and phosphate molecules
Rungs of the ladder are made of nitrogen bases
Made of 5 elements: carbon, hydrogen, oxygen, nitrogen, and phosphorus