Chapter 11 Flashcards
Transport in Plants (17 cards)
Osmosis
net diffusion of water molecules across partially permeable membrane from solution of high Ψ to one with low Ψ
Partially permeable membrane
membrane that’s permeable to some substances but not to others
Water potential (Ψ)
measure of ability of water molecules to move into a solution. Pure water has the highest Ψ.
Turgid
description of plant cell with high internal pressure so cytoplasm pushes against the cell wall
Flaccid
condition of plant cell where internal pressure is lost and cytoplasm doesn’t push against the cell wall
Plasmolysis
plant cell that has lost water by osmosis, cell contents shrinks and cell membrane and cytoplasm pull away from cell wall
Turgor
condition of plant when cells are turgid
Wilt
changes in plant when it loses too much water, leaves droop and collapse
Root hairs
specialised cells on surface of root, take up water and mineral ions from soil
Transpiration
loss of water vapour from leaves of plants
Transpiration stream
passage of water and mineral ions through roots, stem and leaves
Lumen
space in middle of tube such as artery or xylem
Lignin
woody material present in some cell walls, strengthens and makes cell impermeable to water
Sieve plate
specialised end wall of sieve tube, holes allow connection of cell to next cell
Sieve tube
cell found in phloem, consists of tube to transport photosynthesis products
Companion cells
specialised cell lying next to sieve tube controlling its activities
Vascular bundles
xylem and phloem grouped together in stem or root