Transport of Water & Mineral Ions Flashcards
All 6 cards in this deck
What is transpiration?
The evaporation of water from the leaves and its diffusion out through the stomata, which pulls water up the plant.
What are the steps of the transpiration stream?
e.g. water going from soil to air
- Water enters root hair cells by osmosis.
- Water is pulled up the xylem from roots to leaves.
- Water evaporates in the leaf and diffuses out through the stomata.
What are stomata and what do guard cells do?
Stomata are pores in the leaf surface; guard cells open and close them by changing shape as water enters or leaves.
Why are most stomata found on the lower surface of a leaf?
The lower surface is cooler and shaded, so less water is lost by evaporation.
What makes it possible for mineral ions to be carried from the roots up to the leaves?
They are dissolved in the water, so they travel up the xylem in the transpiration stream.
In the light, which gases diffuse into and out of a leaf through its open stomata?
Carbon dioxide diffuses in for photosynthesis; oxygen and water vapour diffuse out.