The Discovery of DNA

Genetics and the patterns of heredity were described by Gregor Mendel, but what Mendel did not know was how traits were coded, or the chemistry of heredity.  What was known was that genetic information was carried on the chromosomes in eukaryotic cells, and that chromosomes are composed of DNA and protein. Scientists suspected that DNA and proteins were the molecules of heredity, but they had yet to find the evidence to support their predictions. In this interactivity, learn about the key events in the discovery of DNA. Click the player button to begin.

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Rosalind Franklin

Rosalind Franklin was a British chemist who is best known for her role in discovering the structure of DNA. Through her use of X-ray diffraction, Franklin was able to extract DNA fibers and arrange them in parallel bundles. She studied the fibers and their reactions to different conditions. Franklin even produced photographs of DNA, the most important being titled photograph 51.

Without her knowledge, her partner Maurice Wilkins shared her data, along with photograph 51, with James Watson and Francis Crick. Watson and Crick used the newly acquired data to publish the proposed structure of DNA in March of 1953. For their efforts, they were awarded the Nobel Prize. Without ever receiving credit for her contributions to Watson and Cricks proposal, Franklin passed away from ovarian cancer in 1953. She was 37 years of age.

The Discovery of DNA Review

Now that you investigated the discovery of DNA, review your knowledge. In this non-graded interactivity, drag and drop each of the events in the correct order in which they occurred. Click the player button to get started.