Microbes known as bacteria have simpler cell structures than many other types of creatures. One DNA loop serves as their command center and houses all of their genetic data. Instead of a nucleus, some bacteria contain an additional ring of genetic material called a plasmid. Genes that offer the bacterium a competitive edge over other bacteria are frequently found on the plasmid. For instance, it could have a gene making the bacteria immune to a specific antibiotic.
Bacteria are classified into five groups according to their basic shapes: spherical (cocci), rod (bacilli), spiral (spirilla), comma (vibrios) or corkscrew (spirochaetes). They can exist as single cells, in pairs, chains or in clusters.
Synonyms: microbe, bacilli
