The Human Genome Project – discovering the human blueprint

Activity 1

Changes in genetic research and knowledge

It is less than 100 years since the significance of Mendel's work was first realised.

  1. Describe how our understanding of inheritance has changed since Mendel's work in the 1860s;

  2. Using examples from genetics, explain how the nature of scientific research has changed.

Teachers notes

  1. Mendel's work showed that genetic traits were discrete, indivisible units which were inherited independently of each other. Other workers then found that some genes were inherited with others (linkage groups). Cytological work in the early 1900s then related these linkage groups to chromosomes. At this time traits were given the name 'genes'.

    Subsequent work showed that Mendel's traits can indeed be divided and are actually segments of DNA (a sequence of nucleotide bases) and that most genes code for the structure of a polypeptide. So a sequence of nucleotides codes for a sequence of amino acids that is a protein. Proteins are essential components of all cells as an integral part of cell scaffolding and membranes as well as cellular enzymes. Genes therefore control an organism's structure and function.

  2. The major changes are:

    • that research has shifted from interested amateurs to highly specialised research scientists and from individuals working alone to scientists working in teams (Mendel versus the teams involved in the Human Genome Project);

    • from very simple measuring devices to sophisticated 'black boxes' (The difference between Mendel's tall and dwarf peas could easily have been measured with a ruler while machines obtain most of the information for DNA analysis);

    • from hand-done calculations to computerised recording, calculation and interpretation of results (DNA scientists analyse much of their data using computers);

    • from the news about discoveries taking months or even years to spread across the world to being almost instantaneous (in Mendel's time communication was restricted to letters, the delivery of which was unreliable and slow whereas modern scientist working in similar fields are in daily contact by phone or e-mail;

    • from whole organism investigation to investigations at the sub-cellular (or molecular) level (Mendel looked at the size and shape of pea plants and seeds). Modern geneticists now look at morphology and attempt to relate appearance to DNA sequence.
    The Human Genome Project has accelerated these changes in the nature of scientific research from manual tasks to computer and machine-driven tasks. This is producing a rapid increase in our understanding of our genes and how they work.
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Posted February 1997.