Bacteria

The term "bacterial growth" generally refers to growth of a population of bacteria, rather than of an individual cell. Individual cells usually reproduce asexually by means of binary fission, in which one cell divides into two cells. Thus, bacterial growth of the population is a geometric progression of numbers of cells, with division occurring in regular intervals, called generation time, ranging from 15 minutes to 16 hours, depending upon the type of bacterium. In addition, some filamentous bacteria (actinomycetes) reproduce by producing chains of spores at their tips, while other filamentous species fragment into new cells.