Agar plates are laboratory tools used to grow and study microorganisms, such as bacteria and fungi. They consist of a flat dish filled with a gelatinous substance called agar, which is derived from seaweed. This medium provides nutrients that support the growth of various organisms, allowing scientists to observe their characteristics and behaviors. Researchers often use agar plates to isolate specific strains of microbes or to test the effectiveness of antibiotics. By spreading a sample on the surface of the agar, they can create distinct colonies, making it easier to identify and analyze different species.