xylem and phloem lesson 2
DESCRIPTION
Biology side B transport in plantsTRANSCRIPT
Label and annotate the phloem, xylem and meristem on the laminates
2. Flowering plants have two tissues to transport materials, xylem and phloem. The diagram below shows the outline of a transverse section of the root of a dicotyledonous flowering plant.Sketch in and label the areas occupied by the xylem and phloem.
[Total 2 marks]Booklet Page 6
Memorise this….
Recreate!
Xylem
XylemHollow Dead cells end to endContinuous Tubes (Narrow)Strengthened with Lignin
Pits in wallAllow movement across
No cell contents, no nucleus or cytoplasm, no end walls
Structure/Feature How adaptation worksDead cells aligned end to end in a continuous columnNarrow tubesLignin deposited in the wallsPits in the lignified wallsNo end walls or cell content
How Xylem is Adapted for its role:
Page 7
Memorise this….
Recreate!
Phloem
Two types of cell: Sieve Tube elements and Companion Cells
Sieve Tube elements:
Little cytoplasm and no nucleusEnd to end to make a tube
Cross walls perforated by pores – Sieve plates
Phloem
Companion Cells
Large nucleus and dense cytoplasm
Lots of mitochondria – ATP for active processes
Linked by plasmodesmata
Structure/Feature How adaptation worksSieve tube element
Mitochondria in companion cellLittle cytoplasm
plasmodesmata
How Phloem is Adapted for its role:
Label diagrams in booklet and make sure key words defined
On mini wb:1.Describe the structure of a xylem vessel2.Why do xylem vessels have pits3.Explain why sieve tube elements are not true cells
Xylem Phloem
Both Xylem and Phloem