Plants and Structure Flashcards
(23 cards)
What is the function of the leaf
- Where photosynthesis occurs + gas exchange occurs
- water evaporated off them
Function of the xylem
- transpiration
- Tubes that carry water up the plant
- Dissolve minerals
What is transpiration
Diffusion of water through the roots and up the xylem
(Unidirectional)
What is the rate of transpiration increase by
Air movement or temperature
What is the function of the roots
- Where water enters plant via osmosis
- where minerals enter plant via active transport
Adaptation of root
- hair like structure with large surface area
Why is a large surface area needed in a root
So rate of exchange is maximum
Function of meristem
Where stem cells are produced
Function of flower
Plants reproductive organs
Function of phloem
Carry sugars, food and sap up and down plant
- translocation
What is translocation
Movement of sugars, food and sap up and down plant
(Bidirectional)
Rates that increase translocation
- Increasing temperature
- increasing air movement
- decreasing humidity
Reason for increasing rate of translocation
Water evaporates faster
Structure of the leaf
1) waxy cuticle
2) upper epidermis
3) palisade
4) spongy layer
5) lower epidermis
Structures in the lower epidermis
Stomata and guard cells
Function of waxy cuticle
Waterproof to prevent water loss
Function of upper epidermis
Transparent to let light pass through palisades
Function of palisades
Full of chloroplasts where photosynthesis occurs
Function of spongey layer
Gaps to allow gas exchange
Functions lower epidermis
Bottom of leaf with stomata and guard cells
Function of stomata
Allows gases and water in and out by opening and closing
Function of guard cells
Changes size of stomata to control rate that gases come in and out of
Example of why the guard cells change stomata size
Close/ make small at night as there is no light for photosynthesis
