Antiport This process facilitates transport of molecules in both the directions across the membrane and their movement is independent of each other.

The rate and direction of osmosis depends upon both the pressure gradient and concentration gradient.

The plant dies due to exosmosis. As the solution outside the plant is an hypertonic solution, and the plant celsl are hypotonic in nature, so there is a gradual movement of water from plant cell to outside urea solution leading to plasmolysis of root cells and plant dies gradually.

Due to imbibition of water by seed materials (starch and protein), pushes the seedlings out of the soil, thus the seed swells and imbibition pressure increases inside the seed, which contributing for germination of seeds.

Transpiration pull is the physiological phenomenon which is responsible for the upward movement of water in trees of height up to 20 m . As the water molecules transpire from stomata, it pulls water molecules up ward to the leaf from the continuous chain of water molecules carried by xylem.

This transpiration from leaf creates a pressure gradient between the atmosphere and sub-stomatal cavity and intercellular spaces of leaf. This gradient is transferred to photosynthetic cells and then on to xylem of leaf vein.

It results in a force called "transpirational pull" that can lift water upto 130 m high, through a xylem column.