Bacteria are simple unicellular organisms that can be found in nearly every environment on Earth. All bacteria are prokaryotic—they do not have a true nucleus or organelles with membranes.
2. Two Bacterial Groups
DNA studies suggest that there are two distinct groups of bacteria. Therefore bacteria are divided into two kingdoms—archaebacteria and eubacteria.
3. Where Are Archaebacteria Found?
Some archaebacteria are found in extreme environments, such as hot springs and salt lakes, while other species live in the ocean and soil.
4. Where Are Eubacteria Found?
Eubacteria are more common than archaebacteria and are found in soil, water and our bodies.
5. Beneficial and Harmful Bacteria
Archaebacteria and eubacteria are diverse kingdoms of organisms that contribute to oxygen production, food production, decomposition, medical applications and biotechnology. Some bacteria are harmful and cause disease.