Chapter 9 - Transport in Plants Flashcards
Why do multicellular plants need transport systems?
Metabolic demands - Cells need to photosynthesise and produce their own glucose and oxygen
Large size - need effective transport systems to move substances considerable distances
SA:V ratio - plants cannot have everything diffuse into every cell and tissue so transport systems are needed to reach every cell and tissue
What is a herbaceous dicot?
Soft tissue, short life cycle where leaves and stems die down after the growing season to ground level
What is a woody dicot?
Hard lignified tissue
What is a monocot plant?
Single cotyledon
Long narrow leaf
Parallel veins
Vascular bundles scattered
Floral parts in multiples of 3
What is a dicot plant?
Two cotyledon
Broad leaf
Network of veins
Vascular bundles in a ring
Floral parts in multiples of 4 or 5
What is the vascular bundle?
The xylem and phloem arranged in a bundle in the stems and leaves
What is the structure and functions of the xylem?
Mostly dead tissue
Transports water and mineral ions from roots to leaves in one direction
Provides plant support
Long hollow structures made of cells fused together with lignified cell walls
Lignin can be found in rings, spirals or solid tubes
Contain unlignified areas called boarded pits where water leaves the xylem
What are xylem fibres?
Long cells with lignified secondary cell walls t
Provide additional support
Do not carry water
What is the xylem parenchyma?
Cells with thick cell walls
Store food
Contain tannins that tastes bitter to deter herbivores
What is the phloem?
Living tissue
Transports food around the plant in the form of organic solutes
Flow can go up and down the planf
Delivers sugars and amino acids needed for respiration and synthesis of other useful molecules to every cell in the plant
What is a phloem sieve tube?
Many cells joined end to end to form a long hollow structure
Not lignified
Areas between cells are perforated to form sieve plates letting the contents flow through
Mature phloem cells have no nucleus or vacuole and very limited number of organelles
What is a companion cell?
Maintain a nucleus and organelles and act as a ‘life support system’ for the sieve tubes
Form with the sieve tubes that link to the sieve tubes via plasmodesmata
