Transport in plants
- Xylem and phloem
- Xylem
- water and mineral ions
- support
- Phloem
- sucrose
- amino acids
- Position
- root: centre
- stem: outer ring
- leaf: veins
- Xylem structure Supplement
- lignin walls
- no contents
- no cross walls
- Xylem
- Water uptake
- Root hair cell
- absorbs water and ions
- large surface area
- Pathway of water
- root hair cells
- root cortex
- xylem
- mesophyll
- Stain investigation
- stem in dye
- stain in xylem
- Root hair cell
- Transpiration
- Definition
- loss of water vapour
- from leaves
- Mechanism
- evaporation from mesophyll
- diffusion through stomata
- Factors increasing rate
- temperature
- wind speed
- Humidity Supplement
- more humid: slower rate
- less steep gradient
- Leaf structure Supplement
- air spaces
- stomata number and size
- Transpiration pull Supplement
- water column
- attraction between molecules
- Wilting Supplement
- cells lose turgor
- leaves droop
- Definition
- TranslocationSupplement
- Moves sucrose, amino acids Supplement
- in phloem
- Source Supplement
- releases sucrose
- e.g. mature leaf
- Sink Supplement
- uses or stores
- e.g. fruit, root tip
- Source and sink at different times Supplement
- tuber stores then releases
- Moves sucrose, amino acids Supplement