B7.1 Transport in plants Flashcards
What is glucose made in photosynthesis converted into for transport?
Sucrose
What does the xylem do?
It transports water from the roots to the leaves (up the stem)
What are the walls of the xylem made out of and why?
Made of lignin to keep its shape
Describe the movement of water
- Water moves into the plant by osmosis via the root hair cells
- Travels through the root cortex cells and up the xylem vessels to the leaves
- In the leaves, the water leaves the xylem vessel and moves through the spongy mesophyll cells
List the places water goes through in order
Root hair cell –> root cortex cell –> xylem –> mesophyll cell
Define transpiration
The loss of water vapour from plant leaves by evaporation of water at the surfaces of the mesophyll cells followed by diffusion of water vapour through the stomata
What are xylem vessels made up of?
dead xylem cells
Why are the end walls of the dead cells broken?
To allow water to move through
What do the root hair cells do?
It absorbs water via osmosis and uptakes mineral ions via active transport
List the 4 factors affecting the rate of transpiration
- Humidity
- Temperature
- Light intensity
- Wind speed
What are phloem cells made up of?
- Columns of living cells
Why are the end walls of phloem cells partially permeable?
To allow food products to move up and down the phloem vessels
Define translocation
The movement of sucrose and amino acids from the leaves (sources) to the growing regions of the plant and storage organs (sinks)
Describe the movement of phloem cells
Can move up or down
What are root hair cells adapted for?
The absorption of substances
What increases the root hair cells’ surface area?
Fine extensions
The water molecules move down their water potential gradient because…
The water potential out the root is higher than inside the cytoplasm
In the stem and leaves, the xylem and phloem are grouped together as …
Vascular bundles
Explain the process of investigating water movement through a plant
- Add food coloring to the water given to the plant
- Food coloring is soluble and is carried through the plant with the water in the xylem
- After a day or two in colored water, the veins of the leaves and flowers of a plant will show the color
