Using the term water potential how water moves from vascular tissue to atmosphere?

Answer 1

I took the following from the website below:

http://www.cybered.net/commerce.asp?CatId=310&PrId=X5002116

The water is taken in by osmosis through the root-hair cells. The water then passes to the xylem tissue in the middle of the root and travels up the stem via the same xylem tissue. From the xylem in the leaf it passes through the air spaces and out into the atmosphere through the stomata.

water potential draws in water from the soil and moves up through the xylem into the leaves

This is possible because water is polar molecule and cohesion and adhesion resulting from Hydrogen bonds drag water up the xylem until they reach the stomata.

Answer 2

The xylem vessels have a high water potential. Water diffuses from xylem vessels in the veins down its water potential gradient through adjacent cells. Water then evaporates from the spongy mesophyll which have numerous large intercellular air spaces to the atmosphere.

Answer 3

This is a process known as transpiration. Water is absorbed through the roots (Source) of the plants by osmosis across a negative water potential gradient. Water is then able to travel up through the plant via the xylem vessels. Cohesion of individual water molecules creates a chain of hydrostatic pressure which allows the water to move through the xylem to the leaf across a negative water potential gradient. Once water is at the leaf (Sink), it exits the leaf through the stomata and is removed by environmental factors such as wind and evaporation. The removal of water from the leaf maintains the negative gradient required for water to travel through the plant by osmosis, thus maintaining a chain of transport from the root to the leaf.

Answer 4

Plants use xylem to transport water from the roots to the rest of the plant. Sometimes plants use root pressure to raise water through the xylem into the plant.

Answer 5

No, water will move from higher water potential to lower water potential.