What is a microorganism?
Microorganisms are tiny. They are so small they can only be seen with a microscope. Yeast is a helpful microorganism which makes bread rise. Bacteria is a microorganism which breaks down plants into nutrients.
Microorganisms are also known as 'germs'. Harmful germs can make us unwell. Good hygiene will avoid spreading these germs. Use soap and hot water to wash your hands after preparing food or using the toilet. This will kill bacteria.