Final answer:
The main driving force for transporting water to the leaves of plants is osmotic pressure, with negative water potential, cohesion, and adhesion also facilitating this upward movement against gravity.
Step-by-step explanation:
The driving force that brings water to the leaves on the plants is primarily due to osmotic pressure. This process begins as water enters the plant through the root hairs due to a negative water potential, which is a result of the osmotic pressure generated by the differences in solute concentrations inside and outside the plant roots. As water is used in photosynthesis and lost through transpiration, the osmotic pressure inside the leaves decreases, thereby drawing more water up from the roots to replace it. This movement of water is critical for the plant's ability to transport nutrients and maintain its structure.
In addition to osmotic pressure, other mechanisms such as cohesion and adhesion also play a role in water transport through the plant's xylem. These forces, along with capillary action, facilitate the upward movement of water against gravity, which is especially important for tall plants and trees.