Final answer:
Complex media is a type of bacterial growth medium with an unknown chemical composition. It enhances the growth of some microbes, inhibits the growth of unwanted bacteria, and distinguishes between different types of bacteria.
Step-by-step explanation:
Complex media is a type of bacterial growth medium where the exact chemical concentrations are unknown. It is characterized by containing extracts and digests of yeasts, meat, or plants. The precise chemical composition of the medium is undetermined and variable, and the amounts of individual components are unknown.
Complex media serves multiple purposes, including enhancing the growth of a group of microbes, inhibiting the growth of unwanted bacteria, and distinguishing between different types of bacteria. Examples of complex media include nutrient broth, tryptic soy broth, and brain heart infusion.