1
Q
Function of xylem
A
- Carries water & mineral salts
2. Transport from roots to rest of plan
2
Q
Function of phloem
A
- Carries products of photosynthesis
2. Transport from leaves to rest of plants
3
Q
Monocotyledons
A
Long, narrow leaves
4
Q
Dicotyledons
A
Has leaves with blades and stalk (particles), broad leaves
5
Q
List of plant cells
A
- Epidermis
- Parenchyma
- Collenchyma
- Endodermis
- Mesophyll
- Pericycle
- Vascular tissue
6
Q
Transport of water
A
- Water uptake near root tips
- Water enters xylem
- Water moves up xylem
- Water moves from xylem to leaf cells
- Evaporation of water into leaf air spaces
- Transpiration of water vapor through open stomata into air (mainly underside leaf)
7
Q
Transpiration
A
The loss of water vapor from a plant to its environment by diffusion down a potential gradient, most transpiration takes place through stomata in leaves
8
Q
Water movement through leaves
A
- Water vapor diffuses from air space through open stomata
- Water carried away from the leaf surface by air movements
- This reduces water potential inside the leaf
- Water evaporates from mesophyll cell wall into the air space
- Water moves through the mesophyll cell wall or out of the mesophyll cytoplasm into cell wall
- Water leaves xylem vessels through non-lignified area such as pit; may enter the cytoplasm or cell wall of a mesophyll cell
- Water moves up the xylem vessels to replace water lost from the lead
9
Q
Factors affecting the transpiration
A
- Humidity
- Wind speed/temperature
- Light intensity
- Very dry conditions
10
Q
Xerophytes
A
Plants that live in places where water is in short supply, keep water loss minimal
- Curled leaf
- Sunken stomata
- Cuticle contains cutin, a waterproof substance
- Hairs
- Leaves are needles (reduced surface area)
- Swollen succulent stems (to store water)
- Stomata only at underside of leaf
11
Q
From xylem across leaf
A
- Symplastic pathway
2. Apoplastic pathway
12
Q
Symplastic pathway
A
- Water enters cytoplasm by osmosis through partially permeable membrane
- Water moves into sap vacuole, through partially permeable membrane
- Water may move from cell to cell via plasmodesmata
- Water may move from cell to cell via adjacent cell surface membrane/ cell wall
13
Q
Apoplastic pathway
A
- Water enters cell wall
- Water moves through cell walls
- Water may move from cell wall to cell wall via intercellular spaces
- Water may move directly from cell wall to cell wall
