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Bacteria
Quick revise
To show just how important our skin is in keeping out bacteria, the students are asked to visit the boy's toilets lit only by ultraviolet light. Under these conditions bacteria and other organic matter glow in the dark. These fluoresce under UV light, absorbing the normally invisible UV light re-emitting it as visible light that we can see. The students also take swabs from different areas of the toilets to find out which are most heavily populated and then they use a biotrace luminometer to analyse the results. The highest readings were found nearest to the sinks where the presence of warm water encourages bacterial growth.
Exam Tip: Break down your revision about microbes into several smaller chunks: bacteria and viruses, entering the body, the immune system and immunisation. There's a lot to learn here so think about writing mini-essays to help you remember material. Use bullet points to order your thoughts.
Example Exam Questions:
- In hospitals, it is very important that nurses and doctors wash their hands thoroughly after examining each patient. Explain why.
- Describe how you could use Petri dishes filled with sterile nutrient agar to find out whether doctors and nurses wash their hands thoroughly enough in a hospital.
