Transport, storage and gas exchange in flowering plants Flashcards
What does autotroph mean?
Something that can make its own food
Are plants autotrophs?
Yes, they make their own food via photosynthesis
How do roots absorb water?
Osmosis- cytoplasm of the root hairs is more concentrated than the soil water
How does water get from the root hairs to the xylem vessels?
Water diffuses from the root hairs across the ground tissue to the xylem vessels.
What does xylem do?
Forms a pipeline from the roots to the leaves.
How does water move upwards?
Root pressure and Transpiration
Describe how root pressure works.
- Water enters roots by osmosis
- Water pushes water molecule in front of it up the xylem
What is transpiration?
Loss of water vapour from the leaves and other aerial parts of the plant
Where does transpiration occur?
Occurs through the stomata.
Describe how transpiration works.
- Water evaporates from the cells in leaves- cells become turgid
- Cells are now more concentrated than xylem cells
- Water moves from xylem to ground tissue via osmosis
- Water evaporates from ground tissue into air spaces
- Air spaces= water diffuses out of stomata
- As water molecule pulled from the xylem by osmosis it “pulls” the next water molecule
- Water pulled up through the plant by transpiration
How is transpiration controlled?
- Waxy cuticle
- Stomata on underside of leaf
- Guard cells control the opening and closing of the stomata
What is the mineral calcium used for in plants?
Formation of cell walls
What is the mineral magnesium used for in plants?
Formation of chlorophyll
How are minerals absorbed into the roots?
- Active transport- requires energy
- Diffusion (does not require energy)
How are minerals transported?
In the xylem, dissolved in water
