Transport of Water & Mineral Ions Flashcards

All 6 cards in this deck

What is transpiration?

The movement of water from the roots, up the xylem and out of the leaves, driven by evaporation of water from the leaves through the stomata.

Name the cells that change the size of the stomata.

Guard cells.
e.g. when they lose water and become flaccid the stomata get smaller, reducing water loss.

True or false? In most leaves the stomata are found mainly on the upper surface.

False. Most stomata are on the lower surface — this reduces water loss by evaporation while still allowing gas exchange for photosynthesis.

Which gases move in and out of a leaf through the stomata?

Carbon dioxide and oxygen diffuse in and out (in the light, carbon dioxide goes in for photosynthesis and oxygen comes out). Water vapour also escapes through them during transpiration.

How are mineral ions carried from the roots to the leaves?

Dissolved in water, up the xylem in the transpiration stream.

What happens to a stoma when its guard cells become turgid?

It opens — the guard cells swell with water and the pore between them widens.