This practical is based on a real sequence of experiments conducted on the fruitfly, Drosophila melanogaster. The idea is that you follow the same sequence of questions, experiments, deductions and more refined questions that was followed by the original researchers.
First, you will be invited to read background notes on the biological problem. These notes are in pdf format, and you are advised to keep the pdf open on your computer so that its contents remain available to you as you follow the sequence of questions in the practical. The questions will begin by testing your understanding of the system itself, and will then present new information and invite you to make deductions from it. Feedback is available continuously and, if you choose an incorrect answer, you can access a page explaining why it is wrong and why the right one is right, before going on.
This practical is about the growth of the imaginal discs of insects. You can read an introduction to imaginal discs, and a particular puzzle about how they grow, in this pdf (right-click and open in a new tab, so that you do not lose your place here).
When you are ready to move on, click here.