Consider the following statements:

1. A dendritic drainage pattern commonly develops where rocks have broadly uniform resistance to erosion.
2. A trellised drainage pattern may develop where alternating bands of hard and soft rock guide tributaries along the rock structure.
3. A watershed separates streams flowing down opposite sides of an upland divide.
4. A consequent stream develops independently of the initial slope of the land.

Which of the statements given above are correct?