Transport Systems In Plants Flashcards
What are phloem tubes made from?
Made of columns of living cells with small holes in the ends to allow stuff to flow through.
What do the phloem tubes transport ?
Food substances (mainly dissolved sugars)
Where do the phloem tubes transport substances?
The food substances made in the leaves are transported to growing regions (new shoots) and storage organs (root tubers)
Which direction does the transport flow in phloem tubes?
In both directions
What do xylem tubes do?
They transport water and minerals from the roots to the stem and leaves in the transpiration stream.
What are xylem tubes made of?
Made of dead cells
What is the structure of the xylem tubes?
Dead cells joined end to end with no end walls between them and a hole down the middle
What is transpiration caused by?
Evaporation and diffusion of water from inside the leaves.
What happens when there is a shortage of water in the leaf?
More water is drawn up from the rest of the plant through the xylem vessels to replace it.
Why is there a constant transpiration stream through a plant?
As water is drawn up through the xylem vessels to replace lost water so this means more water is drawn up from the roots so the transpiration stream is constant.
What process do root hair cells use to take in minerals?
Active transport
Why can’t minerals be taken in by diffusion in root hair cells?
The concentration of minerals is higher inside the root hair cell than in the soil so diffusion won’t work meaning minerals must be taken in by active transport.
What are root hair cells specialised for?
Absorbing water and minerals
Why are water and minerals important in the plant?
Water is needed for photosynthesis and to make the cells turgid so the plant doesn’t wilt.
Minerals are needed for healthy growth.
What is the path the water takes through the plant?
Roots ➡ xylem ➡ leaves ➡ evaporation
This is the transpiration stream.
