Transport in plants Flashcards
Function of Xylem?
Xylem transports water and mineral ions from the roots upwards
Function of phloem?
Transports manufactured food substances(sucrose and amino acids) from the leaves to all parts of the plant
Adaptations of xylem?
Strengthened by deposits of lignin
Dead xylem cells lign the xylem and the gaps are filled witb lignin
Airtight to prevent leaky water
Adaptations of phloem?
Made up of long cells called sieve tubes and companion cells
In the middle, it is made up of a “spongy” tissue known as sieve plates to transport sucrose and amino acids
Translocation definition?
The act of transporting minerals from 1 part of the plant to the other
A sink in translocation?
The roots, flower etce
A source in translocation?
The leaves
How does water enter a plant?
From the root hair cells via osmosis
Then, water passes across the root from cortex cell to cortex cell via osmosis till i
How do mineral ions enter into the plant?
Through active transport
How is the root hair cell adapted for its function of absorption of water/mineral ions?
It has many mitochondria to supply the energy required for active transport. It is long and narrow to increase the surface-area-to-volume ratio to save resources.
Why do the guard cells turn flaccid in the night?
To prevent water loss due to transpiration
What is transpiration pull?
Water evaporates out of the spongy mesophyll cell. This lowers the water potential inside the spongy mesophyll cell. This causes water to be pulled from surrounding cells via osmosis. It repeats until water is pulled out of the xylem. Water has a cohesion force, so it connects and pulls water from the roots up.
Parts of the leaf
Waxy cuticle, upper epidermis, palisade mesophyll, spongy mesophyll, lower epidermis, waxy cuticle and guard cells
