A pure culture contains?

A pure culture is defined as a laboratory culture that contains only a single species of microorganism. This is essential for various research and diagnostic purposes because it allows for the study of the characteristics and behavior of that particular organism without interference from others.

In microbiological studies, obtaining a pure culture is crucial when trying to isolate the effects of a specific microorganism in an experiment or when identifying pathogens in clinical samples. By ensuring that only one identified species is present, scientists can accurately assess its properties, such as its growth requirements, biochemical activities, and potential pathogenicity.

Other options are not aligned with the definition of a pure culture. For example, a culture containing two different species or multiple types of microorganisms would represent a mixed culture, which does not meet the criteria for purity. Similarly, a culture that includes only pathogenic organisms still implies the presence of multiple species, thus disqualifying it as a pure culture.