From Wikipedia, the free encyclopedia. An agar plate is a Petri dish that contains a growth medium (typically agar plus nutrients) used to culture microorganisms or small plants like the moss Physcomitrella patens. Selective growth compounds may also be added to the media, such as antibiotics.gar plates may also be indicator plates, in which the organisms are not selected on the basis of growth, but are instead distinguished by a color change in some colonies, typically caused by the action of an enzyme on some compound added to the medium.
The Missouri-Mississippi River system at about 3,900 miles (6,300 km) in length, it is the fourth longest river in the world. Its average discharge of water makes it the tenth largest river in the world. It is the only river located in North America that made the top ten longest rivers list.
It is believed to be the longest river in the world. Located in Africa, the Nile River lies in the following countries: Kenya, Eritrea, Congo, Burundi, Uganda, Tanzania, Rwanda, Egypt, Sudan and Ethiopia. Watch it in Full High Definition!