1. Looking at microbes in yoghurt

2. What are you looking at?

3. Objectives To learn the key parts of a bacterium cell; To safely use a Gram stain to see bacterium; To use standard form to scale observations. Are you ready?

4. Labelling a microscope Eye piece Focusing knob Clips Mirror Stage Objective lens

5. Recording your results Diagram: Don’t forget to use a pencil and a ruler. Include the magnification (magnification = eye lens x objective lens)

6. Looking at bacteria in live yoghurt You are going to make a Gram stain to see the bacteria that makes yoghurt; Record your observations with a sketch; Annotate your diagram to show the rod shaped bacteria and the magnification.

7. What have we found out? Look at the diagram of the bacterium. Can you label any key parts? How small are the bacterium? Extension: How do bacteria reproduce?

8. Extension: How do bacteria reproduce?

9. Reflection Write a Tweet (140 characters) to summarise your learning in today’s lesson.