B2.2.4 - Plant Transport Systems Flashcards
How many transport systems do plants have?
2
What are the transport systems in plants made up of?
Long vessels formed by lots of cells end to end.
What does the xylem tissue do?
Transport water and mineral ions from the roots to the stems, leaves and flowers. Water diffuses into the roots via osmosis, and mineral ions are transported via active transport.
What does the phloem tissue do?
Dissolve sugars produced during photosynthesis, and other soluble food molecules, from the leaves to all the areas of the plant.
What is the name of the process that phloem tubes do?
Translocation
What structure do phloem and xylem tissues create?
Vascular bundle
What are xylem vessels made of?
Dead xylem cells
Describe the structure of dead xylem cells.
There are no cell walls at the end of this cell. This forms tubes through which the water and dissolved mineral ions can flow. The rest of the xylem cellulose cell wall is thickened. This helps provide support. In woody plants like trees, xylem make up most of the bulk.
What are phloem vessels made of?
Living cells
Describe the structure of the living cells in phloem vessels.
The cell walls of these cells do not completely break down. Instead sieve plates are formed - small holes in the end wall which allow the dissolved sugars to pass through. The connection of the phloem cells effectively forms a tube which allows dissolved sugars to be transported.
How do vascular bundles help provide support?
In the leaf they form a network that supports the softer leaf tissue.
In the stem they are located around the outer edge, providing the stem with strength to resist bending in the breeze.
In the root they are found in the centre, enabling the root to act as an anchor - the root can bend as the plant moves in the wind.
