Generally, each is only a few micrometres in length and can be spherical, spiral or rod-like in shape. They are one of the first inhabitants of Earth and could thrive well in almost all habitats. They can multiply and survive in water, acidic hot springs, soil, radioactive waste, inorganic matter and inside or outside the bodies of living organisms.
Bacteria grow to a certain fixed size then multiply through binary fission. Through this asexual reproduction, bacteria can grow and multiply rapidly and as much as twice its population in every 9.8 minutes.