Although cell polarity is commonly analysed along one, and sometimes two, dimensions, this perspective illustrates how higher-order cell polarity regulates convergent extension — the coordinated ...

The boundary where the two plates meet is called a convergent boundary. Deep trenches appear at these boundaries, caused by the oceanic plate bending downward into the Earth. Deep below the Earth ...

Instead, the two crush together at what is known as a collisional boundary. They crumple and fold. Some pieces of land are thrust over or under other pieces. The result is a mountain range.

When the plate sinks into the mantle it melts to form magma. The pressure of the magma builds up beneath the Earth's surface. The magma escapes through weaknesses in the rock and rises up through ...