Extra Plant Transport Flashcards
What are the three plant types?
Hydrophtes, Mesophytes, Xerophytes
Describe the adaptations of a hydrophyte.
Stomata on upper epidermis, thin cuticle, air spaces for bouyancy, less developed xylem. less lignin, singular vascular bundle
Describe the adaptations of a mesophyte
Waxy cuticle, stomata close at night, shed leave
Define transpiration.
Water evaporating from leaves causing a transpiration stream and tension
Define transpiration stream
Water being pulled up the xylem by cohesion
What does the xylem transport?
Water and mineral ions
What cells do both xylem and phloem have?
Parenchyma (packaging tissue), fibres (provide support)
What is the function of lignin?
Is in rings providing mechanical strength and support, allows adhesions, contains pits which allow leakage, reducing bubbles
Define translocation.
The transport of materials in the phloem from the source to the sink
What 3 experiments prove translocation?
Ringing, Aphids, Radioactive tracers
Describe ringing?
A ring of bark cut away with phloem, sugar being transported is stopped by the ring, bulge of sugar forms above
Describe aphids.
Have specialised mouth called stylets used to penetrate phloem. If anaethetised with CO2 and cut off, sap can be collected and analysed
Describe radioactive tracers
Radioactive CO2 in bag around leaf so incorporated into sugars, aphids feeding used to trace or plant placed on photographic film in dark for 24hours, radioactivity seen as fogginess
Give two functions of stomata?
Allows gas exchange and controls water loss
What is the function of the plasmodesmata?
Transports proteins, enzymes and ATP
How are plants adapted for maximum CO2 uptake?
More stomata so greater area of diffusion
Give two adaptations of palisade mesophyll
Chloroplasts for max light absorption, closely packed for max light absorption
What apparatus is used to measure transpiration?
Potometer
How should you prepare a plant for a potometer?
Cut shoots underwater and at an angle, continuously pour water
What is the role of a reservoir on a potometer?
Resets the position of the bubble
Define resolution
The ability to see more detail
State 2 differences in the xylem of hydrophytes and xerophytes.
Lignin amount, thickness of walls
State two differences between phloem and xylem
Lignin v None, Wide v Thin, Pits v None
