Transport in vascular plants Flashcards
How does water climb a tree?
- Capillary Action
- Transpiration
- Root pressure
What are the 3 transport routes for water an solutes?
- Apoplastic route
-Through the cell wall - Symplastic route
-Through the cytosol - Transmembrane route
-Across the cell wall and plasma membrane
What is water potential?
A measurement of solute concentration and pressure
What does water potential determine?
The direction of movement of water
What does it mean if a plant is wilting?
Turgor loss
What does it mean if a plant is turgid?
The gain of water when a flaccid cell is placed in a solution with lower solute concentration
Changes in ____ open and close stomata
Turgor pressure
Is a cell turgid or flaccid when guard cells bow outward?
Turgid
Is a cell turgid or flaccid when guard cells become less bowed?
Flaccid
What is bulk flow?
The movement of a fluid driven by pressure
Where does most water and mineral absorption occur? Why?
Near the root tip
Where root hairs are, and the epidermis is permeable to water
Efficient movement is possible because mature tracheids and vessel elements have _____ and sieve-tube elements have ______?
No cytoplasm
Few organelles
What is the last checkpoint for selective passage of minerals from the cortex into the vascular tissue?
The endodermis
What blocks the apoplastic transfer of minerals from the cortex to the vascular cylinder?
The waxy casparian strip of the endodermal wall
(made of suberin)
What regulates and transports minerals from the soil to the xylem?
The endodermis
How do water and minerals move from symplast to apoplast?
Through diffusion and active transport
What is transpiration?
The evaporation of water from a plant’s surface
How is water and minerals pulled from root up?
Due to the surface tension of water which creates a negative pressure potential
Where is water potential the highest/lowest? How does this contribute to transpiration?
Highest in the roots, lowest in the outside air
Water travels from high to low potential (roots to air)
Sugars are transported from _____ to _____ via?
Sources to Sinks via the phloem
What is a sugar source?
Where sugars are made-aka the chloroplasts of leaves
What is a sugar sink?
Where sugars end up - roots, seeds, tubers
Where do sugars have to be loaded into before being exported to sinks?
Sieve-tube elements
Can sugars move by both symplastic and apoplastic pathways?
Yes!
