From Academic Kids
Binary fission begins when the DNA of the cell is replicated. Each circular strand of DNA then attaches to the plasma membrane. The cell elongates, causing the two chromosomes to separate. The plasma membrane then invaginates (grows inwards) and splits the cell into two daughter cells through a process called cytokinesis.
Organisms that reproduce through binary fission generally grow exponentially.
This type of asexual reproduction theoretically results in two identical cells. However, bacterial DNA has a relatively high mutation rate. This rapid rate of genetic change is what makes bacteria capable of developing resistance to antibiotics and helps them exploit invasion into a wide range of environments.
Many organisms reproduce by binary fissions, such as:
- bacteria (for example, Rickettsia species that cause diseases such as Rocky Mountain spotted fever)
- Entamoeba histolytica (a protozoan that is a human intestinal parasite)
- Pyrodictium abyssi, an anaerobic hyperthermophilic archaea of deep-sea Hydrothermal vents.
- Schizosaccharomyces pombe, a fungal organism (yeast)
This article contains material from the Science Primer (http://www.ncbi.nlm.nih.gov/About/Primer) published by the NCBI, which, as a US government publication, is in the public domain  (http://www.ncbi.nlm.nih.gov/About/disclaimer.html).