BRAINCAKEMass Transport in Plants
Revision notes for Mass Transport in Plants in AQA Biology (7401). Read the start of any lesson here, then sign in free for the whole lesson, the R.E.C.I.P.E. recall steps and the quiz.
- Specialised Plant CellsRoot hair cells are epidermal cells with extensions of the cell wall and cytoplasm called root hairs.
- TranspirationWater uptake by plants is through the roots.
- Movement of Water into the Root Hair CellsIf the concentration of mineral ions in the soil is higher than the concentration of mineral ions in the root hair cell, then mineral ions are taken…
- Movement of Water across the RootsWater and mineral ions are is taken up by the root hair cells.
- Movement of Water Up the StemThe movement of water up the stem is through cohesion-tension.
- Movement of Water Across the LeafWater moves from the xylem to the mesophyll cells by osmosis.
- Movement of Water Through the StomataStomata are pores in the leaves caused by the curvature of adjacent guard cells.
- TranslocationTranslocation is the movement of organic substances and some minerals from one part of the plant to another.
- Phloem LoadingActive phloem loading uses the apoplast pathway and uses energy and membrane-bound co-transporter protein and a proton pump to move sucrose into the…
- Mass Flow through Sieve Tube ElementsSucrose loaded into the sieve tubes causes the sieve tubes to have a lower water potential.
- Mass Flow ModelA model of the mass flow hypothesis can be set up as in the diagram below: Provided sucrose is continually being produced at the source and…
- Phloem UnloadingSucrose is actively transported out of the sieve tubes into the sink cells.
- Ringing ExperimentsA ring of cells is removed from the outer later of a tree.
- Tracer ExperimentsRadioactive isotopes are used to trace the movement of substances in plants.
- Evidence for Translocation in PhloemA summary of the evidence for translocation in phlem is listed below: 1.