π³ Plants π Amazing plants
Bacteria
π In short
Bacteria are tiny living things, each made of just one cell, and we can only see them with a microscope. They're everywhere: in soil, water and air, on your skin, and even inside your tummy! They're among the oldest living things on Earth.
π€© Did you know?
- Most bacteria are between a third of a micron and two microns across, and a micron is a thousandth of a millimeter.
- The oldest known fossils are of bacteria that lived about 3.5 billion years ago.
- Bacteria multiply by splitting in two, which can happen every 20 minutes.
- Your body has about as many bacteria as it has cells!
π Find out more
π Very tiny
Bacteria are so small that thousands could line up across the little dot at the end of a sentence. They come in many shapes: tiny balls, rods and spirals.
π Friendly bacteria
Most bacteria are harmless, and many are very useful: some live in our gut and help us digest food, some make yogurt and cheese, and some break down dead leaves and make soil rich.
π‘ Harmful bacteria
Some bacteria cause diseases, like sore throats and tooth decay. Doctors treat some of them with medicines called antibiotics.
π― How do we protect ourselves?
Washing hands with soap and water, cooking food well, keeping it in the fridge and brushing your teeth are all simple ways to keep harmful bacteria away.
πΈ More pictures
𧩠Test yourself
1 What do we see bacteria with?
2 Are all bacteria harmful?
3 The oldest known fossils are of bacteria that lived about ?? billion years ago.
4 Which picture shows βBacteriaβ?
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