o The Frog Blog: Science Fact of the Week 26 - Bacteria

Monday, 7 September 2009

Science Fact of the Week 26 - Bacteria


Bacteria are tiny living beings or microorganisms. They are single celled organisms called prokaryotes, which means that they do not contain a nucleus, but do have DNA. They are usually only a few micro-metres in length but normally exist together in billions. Bacteria are about the simplest cells that exist today. A bacterium is about one-hundredth the size of a human cell. Although bacteria are microscopic, they do come in different sizes and shapes. Bacteria are neither plants nor animals but some can photosynthesize, i.e. make their own food. These bacteria are known as Cyanobacteria or Blue Green Bacteria. A number of bacteria cause disease, these are called pathogenic bacteria. Bacteria are everywhere. A gram of soil typically contains about 40 million bacterial cells. The average human has around 1,000 trillion bacteria on their skin alone! There are also bacteria in our stomachs that help us digest the food our body can’t, and there are bacteria in our compost piles that help turn food waste into new soil.

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