 starter activity

1. starter activity Casu marzu is a cheese made from unpasteurised goat’s milk. The cheese is left exposed so that a special cheese fly can lay its eggs on the cheese. The maggots hatch and eat the cheese helping to breakdown the fats and start the fermentation process. The cheese becomes very soft and liquid called lagrima seeps out. The maggots grow to about 8 millimetres long. When disturbed, they can launch themselves for distances up to 15 centimetres. The idea is you eat the cheese, maggots and all!

2. How did scientists discover the cause of disease?  Aims To explore the origins of germ theory & the work of Louis Pasteur

3.  Your task • Read p. 128. Find out what a miasma was. ‘Miasmists’ toured British cities sniffing out evil-smelling quarters and informing the authorities of the health hazard

4. What was a ‘miasma’? • Common sense told people there was a connection between dirt & disease • Miasma – poisonous fumes give off by decaying matter • Strong-smelling herbs & spices countered the effects • Ventilated hospitals improved chances of survival

5.  Your task • Reading for gist. Read pp. 128-9 about the discovery of micro-organisms. You don’t need to take notes! • What contribution did the following men make to the discovery of the causes of disease? • Anthony van Leeuwenhoek • Joseph Lister • Louis Pasteur

6.  Your task • Imagine you have been asked to produce a film explaining the discovery of the causes of disease. You will be given a template for a storyboard. Sketch an image in each box showing the main stages in the discovery. The first box can provide the background and the last one can be the credits!

7.  Your task • Listen to the interview with Robert Koch, the scientist who developed Pasteur’s experiments into bacteria and developed theories on how they caused disease in humans and animals. • How did he help the development of germ theory? • What was secret of his success?

8. Koch’s contribution to germ theory • Identified the bacterium caused anthrax • Other bacteria, e.g. typhoid, TB, cholera identified in same way • Developed a technique to cultivate bacteria and used dyes to make them visible

9. Secret of his success • Built on previous knowledge (Pasteur & Co.) • Repeated experiments to check results (through 20 generations of mice) • Improved testing technology, e.g. developing cultures & dyes Robert Koch, German scientist in his laboratory

10.  Your task • Read pp. 130-1 and create a spider diagram identifying the reasons why diseases were discovered at this time. Include the following categories: observation, new technology, medical knowledge, research teams, individual genius, chance, governments, warfare, other reasons

11. Reasons for the discovery of diseases • Observation – P conducted experiments using sterile flasks in different locations, identifying that particles in air caused decay • New technologies – K developed better ways of growing bacteria & stains to identify them; P & K used new microscope developed by Lister • Medical Knowledge – P called his method of immunising chickens against cholera ‘vaccination’ after Jenner

12. Reasons for the discovery of diseases • Research teams – P used teams of vets & doctors • Individual genius – P said, ‘chance favours the mind which is prepared’ • Chance – chicken cholera solution left exposed showed that germs were weakened by exposure to air

13. Governments – P received money from French govt • Warfare - rivalry between Fr & Germany spurred on new discoveries • Other reasons – better communications; pressure to improve agriculture led to anthrax vaccine

14.  Plenary • What do you think was the most important factor contributing to the development of germ theory?