Background – microorganisms

The main microorganisms in and on our bodies are protozoa, algae, fungi, bacteria and viruses. Most microorganisms are beneficial – for example, there are microorganisms in our large intestine that synthesise vitamins and allow them to be absorbed into the bloodstream. However, a tiny minority are pathogens. These pathogens, often called germs or bugs, are a threat to all life forms.

Articles

• Microorganisms – introduction

• Microorganisms – friend or foe?

• Fungi – the good, the bad and the ugly

• Bacteria – good, bad and ugly

• Bacteria

• Viruses

Activities

• Exploring microorganisms

• Drama with microbes

Image: Medical illustration of multidrug-resistant Pseudomonas aeruginosa bacteria, by Jennifer Oosthuizen for the CDC.