An<unk>  is a sterile Petri dish that contains a growth medium (typically<unk>  plus nutrients) used to culture microorganisms. Selective growth compounds may also be added to the media, such as antibiotics.
Individual microorganisms<unk> d on the<unk>  will grow into individual colonies, each a clone genetically identical to the individual ancestor organism (except for the low, unavoidable rate of mutation). Thus, the<unk>  can be used either to estimate the concentration of organisms in a liquid culture or a suitable dilution of that culture, using a colony counter, or to generate genetically pure cultures from a mixed culture of genetically different organisms, using a technique known as streaking. In this technique, a drop of the culture on the end of a thin, sterile loop of wire is "streaked" across the surface of the<unk>  leaving organisms behind, a higher number at the beginning of the streak and a lower number at the end. At some point during a successful "streak", the number of organisms deposited will be such that distinct individual colonies will grow in that area which may be removed for further culturing, using another sterile loop.
For information on<unk>  preparation, please visit the Wikibooks<unk>  page.
Agar plate
Alar plate
Beevor's axiom
Vesicle 
Spindle apparatus
Interrod enamel
Clitoral crura
Pseudopod