Process
Photosynthesis
Palisade mesophyll cell
What is special about xylem and phloem? How is their structure adapted to their function?
Xylem - impregnated with lignin; prevents free passage of water. Long narrow tubes of dead vessels
Phloem - built up of sieve tubes; helps distributes nutrients all throughout plants. Alive cells. Contains companion cells for energy.
What is it called when a plant loses its turgor pressure and becomes flaccid?
Wilting
What separates phloem and xylem?
Cambium
Transpiration
Absorbs water; Loss of this cell reduces absorption of water
Root hair cell
1) How is root hair cell adapted for absorption of water?
2) How does root hair cell absorb mineral ions?
1) Provides large surface area.
2)ATP (Active transport)
The direction of flow in xylem and phloem?
Xylem : One way flow
Phloem : Bidirectional flow; can happen at same time.
Factors that affect rate of transpiration? And how?
Humidity, increase in humidity reduces the rate of transpiration due to more moisture in atmosphere. Temperature, increase in temperature increases rate of transpiration due to water evaporating faster in hotter temps. Air, increase in air movement increases rate of transpiration due to water vapour will be swept away from the leaf as fast as it diffuses out.
When a plant or cell is placed in a concentrated solution, it begins to shrivel up.
Plasmolysis
Area of gas exchange
Difference of vascular bundle placement in stem and root. (Dicot)
- Stem : Circles around pith
- Root : Forms a cross. Xylem in middle. Phloem at sides
What substances do Aphids gain from the phloem?
Amino acids and sugars.
Source, synthesises materials. Sink, requires materials/storage.
Transports water and mineral ions
Xylem
Importance of Transpiration on a hot sunny day?
Evaporation helps cools leaf down, while absorbing energy and decreasing temperature.
Why does water move between cell walls and not in the cells?
It is a quicker, easier and efficient path to reach cells in need of water.
The tendency of water to move up in narrow tubes.
Capillary Action
Transports amino acids and sugars
Phloem
How does pesticide work and why are foods affected by it, unsafe to eat?
Pesticides acts on an insects nerve system; preventing normal transmissions of nerve. They also leave residue that leaves absorb.
-Summer : highest rate
-Spring : steady balanced rate
-Autumn :Moderate rate
-Winter : Lowest rate
What affects stomata closing and opening? And what controls it