Bacteria are simple organisms that are found in every type of environment, including on land, in the air, in water and on and inside plants and animals. A bacterium (or single bacteria) is a single-celled creature that can take many shapes and forms.
Bacteria were among the first forms of life to form on the Earth, and fossils have been found that date back more than three and a half billion years. Like other living organisms, bacteria need nutrients to survive. If the conditions for their survival aren't met in their immediate surroundings, they will hibernate until their environment is more favorable.
The parts of the bacterium are:
- A thick cell wall
- A cell membrane that lets nutrients in and waste out
- The cytoplasm, which is the space inside the cell that contains its genetic code
Some types of bacteria feature flagella: tiny tail-like structures that allow them to move (largely in water). Other types depend on other forces, including wind, rain and passing animals, to move them around.
Bacteria cannot reproduce in the same way as more complicated organisms, but they can replicate by a process called binary fission. In it, the bacterium essentially splits in two and makes two identical copies of itself.
Bacteria can act in many different ways. They are essential to the functioning of many larger organisms, including human beings. They may also cause diseases and serve to help decompose substances to their various essential elements.