How do Bacteria Replicate?: Binary Fission
Bacteria replicate using their own machinery through a process called binary fission, in which one bacterium divides into two. Though similar, binary fission is a much simpler and faster process than mitosis.
1. The DNA copies itself, forming two genetically identical copies.
2. The cell enlarges, and divides into two new daughter cells.
3. The two daughter cells are clones, genetically identical copies of the parent cell.
Bacteria are well noted for their adaptability; once a bacterium finds a suitable environment, it can divide and multiply very fast. Escherichia coli, for example, can divide every 10 - 20 minutes. This means that in just seven hours one bacterium can generate 2,097,152 new bacteria!
Viruses
A virus does not have cells. A virus particle is basically just a package of genetic information (DNA or RNA) tucked into a protective shell (capsid), that is sometimes surrounded by a protein membrane (envelope).