The proper definition of bacteria is a microorganism that does not have any internal cell membranes. These are the most common microorganisms on Earth. Bacteria are connected to every organism.
Most bacteria cells are less than a millionth of a meter (0.00025 in. ) in length. However most bacterial colonies that live on the surface of marsh mud can be seen clearly to the naked eye without a microscope. The bacterial cells go back about 3.5 billion years. That was when the first two bacterial colonies were formed.
Cells have strand-like DNA, while bacterial DNA have a circular shape. DNA is short for deoxyribonucleic acid, which is also called genetic material.
To live, bacteria need food, warm temperature, and some bacterial cells need oxygen (O2), others do not. Bacteria also feed on dead matter, as well as other living cells.
Bacteria can also be very harmful to humans. Bacteria can cause diseases like the cold, the flu, cholera, etc. That's how bacteria are somewhat similar to viruses.
They can also be very helpful to humans. Bacteria are sometimes used as antibiotics, which can defeat other diseases. Bacteria also helps to breakdown dead matter, rotting organisms, such as dead and rotting trees, dead and rotting food.
So, as you might have learned from this, bacteria can be helpful and harmful. Well, all we have to say about bacteria is, "STAY THE HECK AWAY FROM IT! By completing the following: Do your homework, oopps, wrong website. You should wash your hands with soap and hot water, blow your nose in a tissue, and if you don't have one, we ask you to please blow your nose down towards the ground."