The cell wall is what gives plant cells their shape. The cell wall, not to be confused with the cell membrane, is a rigid structure made up of long cellulose fibers, branching hemicellulose fibers, and pectin. The fluid pressure inside the cell also contributes somewhat to their shape.
The cell goes in a "dormant phase". A good example is the neuron. Neurons are very metabolically active but they don't divide so they go into a phase that doesn't include growth or replication of genetic material.
