Transpiration

Question 1

The movement of water through a plant’s xylem occurs due to the

Answer 1

evaporation of water vapour from the leaves and the cohesive and adhesive properties exhibited by water molecules

Question 2

adhesion meaning in water

Answer 2

Adhesion is the attraction of molecules of one kind for molecules of a different kind

due to water being polar

Question 3

cohesive meaning in water

Answer 3

refers to the attraction of molecules for other molecules of the same kind, and water molecules have strong cohesive forces thanks to their ability to form hydrogen bonds with one another.

responsible for surface tension

Question 4

…………is thedriving force behind the movement of water from the soil

Answer 4

The water potential gradient is the driving force behind the movement of water from the soil (high water potential) to the atmosphere (low water potential), via the plant’s cells

Plants are constantly taking water in at their roots and losing water via the stomata (in the leaves), maintaining the water potential gradient between the roots and the leaves

Question 5

Transpiration refers to the

which is different than the transpiration stream which is what

Answer 5

loss of water vapour via the stomata by diffusion

transpiration stream which is the movement of water from the roots to the leaves

Question 6

Transpiration is important to the plant in the following ways

Answer 6

It provides a means of cooling the plant via evaporative cooling

The transpiration stream is helpful in the uptake of mineral ions

The turgor pressure of the cells (due to the presence of water as it moves up the plant) provides support to leaves (enabling an increased surface area of the leaf blade) and the stem of non-woody plants