3.3.1: Transport in plants Flashcards
What does every cell of a multicellular plant need a supply of?
oxygen, water, nutrients and minerals
Why is their demand for oxygen low?
Because their respiration rate is low. Therefore, their demand for oxygen can be met by diffusion. Their demand for water and sugar is still high.
How do plants obtain water and minerals?
They absorb them from the soil at the roots.
How do plants obtain sugars?
Their leaves can perform gaseous exchange and manufacture sugars by photosynthesis.
Therefore, why do plants need a transport system?
To move water and minerals from the roots to the leaves and to move sugars from leaves to the rest of the plant.
What is transported in xylem?
Water and soluble mineral ions are transported upwards in xylem tissue.
What is transported in phloem?
Assimilates, such as sugars, travel up or down in phloem tissue.
How is the plant transport system different from the animal transport system?
There is no pump and respiratory gases are not carried by these tissues.
What are Dicotyledonous plants?
Those that have two seed leaves. They also have a characteristic distribution of vascular tissue with the vascular tissue distributed throughout the plant the xylem and phloem are found together in vascular bundles.
What other types of cells do the vascular bundles contain?
Collenchyma and Sclerenchyma cells that give the bundle some strength and help to support the plant.
Describe the arrangement of xylem and phloem in a young root.
The vascular bundle is found at the centre of a young root. There is a central core of xylem, often in the shape of an ‘X’. The phloem is found in between the arms of the x-shaped xylem tissue.
Why is this arrangement of xylem and phloem useful?(young root)
It provides strength to withstand pulling forces to which roots are exposed.
What is around the vascular bundles?
young root
A special sheath of cells called the endodermis which plays a key role in getting water into the xylem vessels.
What is just inside the endodermis?
young root
A layer of meristem cells (cells that remain able to divide) called the pericycle.
Where are vascular bundles found the stems?
Near the outer edge of the stem.
