A region can be defined by natural or artificial features. Language, government, or religion can define a region, as can forests, wildlife, or climate. Regions, large or small, are the basic units of geography.
Mechanical weathering breaks rocks into smaller pieces without changing their composition. Ice wedging and abrasion are two important processes of mechanical weathering. Chemical weathering breaks down rocks by forming new minerals that are stable at the Earth's surface.
Deposition is the laying down or settling of eroded material. Sediment deposited in water typically forms layers called beds.
Electricity is used to move DNA molecule fragments through the agarose gel. This technique has lots of applications.
