Discovering the structure of DNA
Who would have thought that science could produce such a s tory of intrigue
and characters? Like all major scientific discoveries, the discovery of the
structure of DNA by James Watson and Francis Crick in 1953 was the result
of years of work from a great number of scientists . Not only is the story one
of great scientific interest, it is also one of great human interest and
controversy.
Your task
This task will see you research one of the individual s or groups of scientists
whose work contributed to the discovery. There are six people to choose from
and your teacher will help you decide which one to focus on:
1.
2.
3.
4.
5.
6.
Griffiths
Avery et al.
Hershey and Chase
Chargaff
Franklin and Wilkins
Watson and Crick
The results of your research will then be produced as a scientific poster,
which you will present to the class.
Step 1: Make a plan
You can work on your own or in a group. If you are working in a group you
will need to take some time to divide up the work.
The task is split up into four parts:
1.
2.
3.
4.
Research the topic
Produce the poster
Practise presenting your poster
Present the poster to your class and answer questions
Your teacher will discuss with you how long you have to do the task. Your
first step is to make a time plan so that you will be ready with the work on
presentation day.
THE STRUCTURE AND REPLICATION OF DNA (H, BIOLOGY)
© Learning and Teaching Scotland 2011
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Step 2: The research
The internet will be the main source of your research but you could also use
textbooks or other books written about the topic. The poster that you produce
will need to include the following pieces of information:





who the scientist(s) is, where they worked and when
the aims of the experiments
what the experiments were, including a diagram
what the conclusions were
other interesting information that you have gathered that lends interest
to the story.
Here are some websites to get you started:
http://www.s-cool.co.uk
A revision site for A-level biology that summarises the experiments
http://osulibrary.oregonstate.edu/specialcollections/coll/pauling/dna/index.ht
ml
http://www.nature.com/scitable/topicpage/discovery -of-the-function-of-dnaresulted-6494318
Follow: A level, biology, DNA and the genetic code
http://www.dnai.org/a/index.html
Follow ‘Finding the structure’ on the menu
Not all of the sites give information about all of the scientists but they are a
good place to start.
Type the name of your scientist followed by ‘DNA’ into your search engine
and you will discover many more sources of information.
Five top tips for your research
1.
2
As you know, the internet is a big place and it is quite easy to find
yourself looking at non-relevant material or even off on a tangent in
the topic area you are studying. Keep focused on the task, stopping
yourself every so often to ask yourself whether what you are looking at
is relevant. Use the 80% rule, which means looking at material
completely related for 80% of the time – if you find yourself wandering
onto something interesting that is a bit off topic then keep it to 20% of
the time (6 minutes in every 30).
THE STRUCTURE AND REPLICATION OF DNA (H, BIOLOGY)
© Learning and Teaching Scotland 2011
2.
Give yourself a time limit.
3.
Plan to stop at regular intervals to discuss what you have found eit her
with your group or with a partner. This will re-focus your work.
4.
Information on the internet may not be reviewed and hence might not
be accurate. Check information from several sources to build a more
accurate picture. Sites from academic institutions , such as universities,
will have an interest in accurate teaching of the subject and so are
generally more reliable.
5.
Do not copy and paste from the internet; this is plagiarism. Instead
make notes and diagrams and add to them from other sources.
THE STRUCTURE AND REPLICATION OF DNA (H, BIOLOGY)
© Learning and Teaching Scotland 2011
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Step 3: Making the poster
Scientists present their work in three main ways: in journal articles that are
peer reviewed, on posters displayed at conferences or at their institution , or
by oral presentation. Posters are meant to show work in a visually appealing
way that makes them accessible and quite quick to read. S cientists might go
to a poster presentation displaying 100 posters so they need to quickly be able
to see what each poster is about.
Your poster will display the results of your research on the sci entist(s) that
contributed to the discovery of the structure of DNA. You could make your
poster on one PowerPoint slide and print it onto A3 paper, or you could make
the poster on card or paper.
The main things to include are described in Step 2. An idea of how to
structure your poster is shown below (your research might not fit this exactly,
but you can be creative):
Title – The title of the work or discovery
By – your names
Introduction – who the
scientist was, where
they worked, some
background information
The experiment – what did they do? What were the results?
Include diagrams
Their conclusions
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And you will never guess... some
interesting piece of information
about the scientist(s) and the
story of the discovery of the
structure of DNA.
THE STRUCTURE AND REPLICATION OF DNA (H, BIOLOGY)
© Learning and Teaching Scotland 2011
Step 4: Presentation of posters
Now is the time to show the rest of the class all your hard work and explain
your research to them so they too understand the place your scientist had in
the unfolding story of the discovery of the structure of DNA. The posters will
be displayed in class and you will be given time to look at posters other
members of the class have produced. You will also need to write down one
question that you want to ask each group about their work.
Your presentation should take 5 minutes and cover the information on your
poster, with extra bits you may not have had room to include. If you are
working in a group you will need to work out who will say which bit.
Five top tips for your presentation
1.
Practice what you will say.
2.
Write down the headings of each chunk of information that you will
give on a small card.
3.
Have the card with you if you are worried about forgetting what to say,
but only look at it if you are stuck – don’t read from it.
4.
Look at your audience, not your poster, and pretend you are chatting
to friends.
5.
Pace yourself by not talking too quickly or too slowly.
6.
Use body language and expression, which will make it more
interesting.
Now think about
What went well?
How could you have researched more effectively?
How could your poster have been improved?
How could your presentation have been improved?
How could the group work have been improved?
THE STRUCTURE AND REPLICATION OF DNA (H, BIOLOGY)
© Learning and Teaching Scotland 2011
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