Transport, Food Storage & Gas Exchange In Flowering Plants (Chpt. 24) Flashcards
Autotrophic
Make own food (plants)
Metabolic processes of plants
Photosynthesis
Respiration
Growth
Reproduction
How is water transported
Through roots
How is water transported into cytoplasm
• Water moves into root hair cells from the soil by osmosis
• water diffuses from cell to cell across the ground tissue until it reaches the xylem
• xylem vessels now transport water to all parts of the plant
↳ form a continuous hollow pipeline from roots to leaves
Adaptations of root hair cells for transport of water
• Thin wall
• Large surface area
Cohesion
Similar molecules sticking together
Water has a high cohesion due to hydrogen bonding
Adhesion
Different molecules sticking together
Water and xylem have lower adhesion
Transport of carbon dioxide
Diffuses through stomata and air spaces
Transport & uptake of minerals - examples & process
E.g. Calcium, magnesium, nitrates, phosphates and potassium ions
• enter root hairs by active transport
• pass into cortex
• pass into xylem which transports them to cells where they are needed
Who discovered the cohesion-tension model?
Dixon & Joly
Name two external stimuli to which plants respond
Light
Gravity
Water
Touch
Temperature
By what process does water enter the root hairs of plants
Osmosis
With regards to the cohesion-tension model:
Name the cells of the vascular tissue in which this movement of water takes place
Xylem
The cohesion - tension model → key points
- Water enters by osmosis and moves into xylem where it causes a build up of pressure
- Cohesion of water molecules due to hydrogen bonding produces an unbroken column of water
- Adhesion of water molecules to walls of xylem prevents column from breaking
- Loss of water by transpiration causes tension in water molecules which pulls the column of water upwards
What causes stomata to close
High levels of carbon dioxide
Drought
DRAW VS of a leaf
DRAW open & closed stomata
