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Watson-Crick Paper Homework
Honors Biology
Read the one-page paper “Molecular Structure of Nucleic Acids” by James Watson and
Frances Crick, published in the scientific journal Nature. Written a little over half a century ago,
this paper completely revolutionized biology, taking the emphasis away from just looking at cells
to studying the molecules inside them—it solidified the new field of molecular biology, one of
the most active fields of science today.
Notice that this paper is very similar to the lab reports you write in class. The first
paragraph is an abstract. The next two paragraphs are an introduction describing what was
currently known about their topic. The fourth paragraph (next to the only diagram) is their
results section, describing what they found. The rest of the paper discusses their results,
pointing out important aspects. The final paragraph is the acknowledgements.
Though the language may be a little confusing, you should still be able to pick up the
important parts of the paper. Skip the fine detail, particularly the measurements and the
chemistry. Remember…while you are already familiar the structure of DNA and all of this is no
surprise to you, this was the first time this radical structure for the molecule had been
proposed!
Answer these questions.
1. What is a scientific journal? What role do they play in science?
2. In the second paragraph, the authors describe a DNA structure proposed by Pauling and
Corey, two amazing biochemists who discovered the α-helix motif in protein secondary
structure. Their model of DNA, however, is a little off (this is sarcasm, kids). Based on
how we know DNA to look today, describe two flaws in their model.
3. Describe the Watson - Crick Model of DNA.
4. One of the revolutionary ideas in this paper is the idea of base pairing. What bases pair
together? What holds them together?
5. Another revolutionary concept is expressed in the eighth paragraph (starting with “In
other words, if an adenine forms one member…”). Explain what Watson and Crick mean
when they say “…it follows that if the sequence of bases on one chain is given, then the
sequence on the other chain is automatically determined.”
6. Why is there no material and methods section in this paper?