2.6 Watson and Crick – Making Models

Using models as representation of the real world—Crick and Watson used model making to discover the structure of DNA.

In 1953, Francis Crick and James Watson published their article proposing the Double-Helix structure of DNA. This represented the culmination of nearly 50 years of research into the function and structure of nucleic acids.  One of the important steps they undertook in determining this was the building of a relatively simple model. 

Models are important tools for scientists as they enable the observation of processes that may not be observable.  Like theories, models may be improved upon and replaced with more accurate ones.  Much important science has advanced through of models in molecular and cell biology and genetics.  However, there may be limitations to this and it raises an important knowledge question:

Is there any distinction to be drawn between knowledge claims dependent upon observations made by sense perception and knowledge claims dependent upon observations assisted by technology?

You can download the original published paper of their discovery from the journal Nature.

Watson and Crick (together with Maurice Wilkins) were awarded the Nobel Prize for Physiology or Medicine in 1962.  More information is at the Nobel Prize website.


Biology Guide. Publication. Cardiff: IBO, 2014. Print. Diploma Programme

Hewitt, Alison. Watson and Crick with the double-helix model. Digital image. Watson and Cancer. UCLA, 7 Mar. 2011. Web. 9 Oct. 2014. <http://newsroom.ucla.edu/stories/watson-and-cancer-193383&gt;.

The Discovery of the Molecular Structure of DNA. Nobel Media, n.d. Web. 08 Oct. 2014. <http://www.nobelprize.org/educational/medicine/dna_double_helix/readmore.html&gt;.


5 thoughts on “2.6 Watson and Crick – Making Models

  1. CharlotteHarvey March 13, 2017 / 2:09 am

    What past questions have been asked about Watson and Crick’s model?


    • simunderhill March 14, 2017 / 9:30 pm

      Hi Charlotte, I don’t think I have seen any yet (but there have only ben two exam sessions). Think about it in general terms e.g. Outline how the discovery of the structure of DNA involved the use of models [3]
      Or in a multiple choice question: Which of the following involved the use of models?
      a) Discovery of cyclins b) the structure of DNA c) semi-conservative replication of DNA d) vaccination

      Just some thoughts.
      Thanks and I hope the blog is proving useful.


      • CharlotteHarvey March 18, 2017 / 5:35 am

        Thank you! I, along with numerous IB students, depend on your brilliantly concise notes and we wholeheartedly appreciate your effort 🙂


      • simunderhill March 20, 2017 / 12:14 pm

        Glad it’s been useful! Thanks for the feedback.


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