what process causes water to enter or leave a cell?

Answer 1

Osmosis causes water to enter or leave the cell. It's a kind of passive transport, taking water from higher concentration to lower concentration. Technically, the concentration gradient causes the net movement of the water.

Answer 2

Osmosis is a partial answer, but active transport can push chemicals in the same or the opposite direction that osmosis would favor. For example, gulls require more water (or less salt, depending how you ant to look at it) in their body fluids than is in sea water. Active transport allows them to excrete concentrated salt solution (you might see crystals forming on the bill). An even more extreme example of active transport is the redwood, which develops the equivalent of 30 atmospheres of pressure in total (though distributed from cell to cell) to pump water to its top.

Answer 3

Osmosis

Answer 4

Osmosis ?

Answer 5

osmosis