3.3.2 The Xylem and Phloem Flashcards
What are the functions of xylem tissue in a plant?
Vascular tissue that carries dissolved minerals and water up the plant
Structural support
Food storage
Where are xylem and phloem tissues found?
Xylem tissue is found, along with phloem tissue and other tissues, in vascular bundles
Where is the xylem in relation to the vascular bundles in the roots, stems and leaves?
- In the roots the vascular bundle is found in the centre and the centre core of this is xylem tissue. This helps the roots withstand the pulling strains they are subjected to as the plant transports water upwards and grows
- In the stems the vascular bundles are located around the outside and the xylem tissue is found on the inside (closest to the centre of the stem) to help support the plant
- In the leaves the vascular bundles form the midrib and veins and therefore spread from the centre of the leaf in a parallel line. The xylem tissue is found on the upper side of the bundles (closest to the upper epidermis)
What is the function of the phloem?
Transport organic compounds, particularly sucrose, from the source (eg. leaf) to the sink (eg. roots). The transport of these compounds can occur up and down the plant
What are the two main cells the phloem is made up of?
Phloem is a complex tissue also made up of various cell types; its bulk is made up of sieve tube elements which are the main conducting cells and the companion cells
Where is the phloem in relation to the vascular bundles in the roots, stems and leaves?
In the roots the vascular bundle is found in the centre and on the edges of the centre core is the phloem tissue
In the stems, the vascular bundles are located around the outside and the phloem tissue is found on the outside (closest to the epidermis)
In the leaves, the vascular bundles form the midrib and veins and therefore spread from the centre of the leaf in a parallel line. The phloem tissue is found on the lower side of the bundles (closest to the lower epidermis)
