28: transport in vascular plants Flashcards
3 ways that water climbs a tree?
- capillary action
- transpiration
- root pressure
water potential
ability for water to do work, measurement that combines the effects of solute concentration and pressure
3 transport routes for water and solutes?
- apoplastic route
- symplastic route
- transmembrane route
apoplastic route
travels through cell wall
symplastic route
travels through the cytosol (no cell wall)
transmembrane route
travels across cell wall and plasma membrane
osmosis
diffusion of water into or out of a cell that is affected by solute concentration or pressure
water moves from ___ water potential to ___ water potential
high to low
turgor loss
causes wilting, but can be reversed when plants are watered
if a flaccid cell is placed in a solution with a lower solute concentration, the cell will?
gain water and become turgid
when turgid, guard cells do what?
they bow outward to open the pore
when flaccid, guard cells do what?
become less bowed and the pore closes
efficient long-distance transport of fluid requires ____, the movement of a fluid driven by pressure
bulk flow
where does most water and mineral absorption occur?
near root tips, where root hairs are located
why is efficient movement possible with mature tracheids and vessel elements?
there is no cytoplasm, and few organelles
water can cross the cortex via which 2 routes?
symplast or apoplast
what is the innermost layer of cells in the root cortex?
endodermis
what is the waxy casparian strip of the endodermal wall made of?
suberin
what blocks apoplastic transfer of minerals from the cortex to the vascular cylinder?
casparian strip
water and minerals in the apoplast must cross what of an endodermal cell to enter the vascular cylinder?
the plasma membrane
what transports the minerals from the soil to the xylem?
the endodermis
transpiration is involves in the transport of?
xylem sap
in a transpirational pull, the surface tension of water creates what?
a negative pressure potential that pulls water and minerals from root up
the products of photosynthesis are transported through the phloem by the process of?
translocation
