UVIC BIO 150 final exam
what acquires nutrients from air water and soil - Answers-plants
what is 96% of plants' dry weight? - Answers-- organic carbon-containing compounds
how does a plant get carbon? - Answers-carbon comes from CO2 absorbed by plant leaves & integrated
into organic compounds (e.g., glucose) by photosynthesis
what do plants get from soil? - Answers-- water
- minerals
- some O2
what part of roots controls solute uptake? - Answers-The plasma membranes
what must solutes move through to reach the water conducting xylem tissue at the center of the root -
Answers-must move through root epidermis & cortex
- this process involves passage across plasma membranes of root cells
plasma membranes are - Answers-selectively permeable, allowing entry of needed minerals and keeping
out unneeded or toxic substances
two possible routes to a plants xylem - Answers-1) intracellular
2) Extracellular
,intracellular route to xylem is when... - Answers-water & solutes cross plasma membrane of root hair,
travel through passages (plasmodesmata) between cells to xylem
the extacellular route to xylem is when... - Answers-solution moves within cell walls and extracellular
spaces; does not cross any plasma membranes until it hits the Casparian strip
What is the Casparian Strip and what does it do - Answers-- a continuous waxy barrier that stops water
and solutes from entering the xylem through cell walls
- forces water & solutes to cross a plasma membrane into an endodermal cell (the ring of cells around a
vascular bundle)
- this plasma membrane regulates mineral uptake for the the intercellular route.
what pulls water up xylem vessels - Answers-Transcription
what is Xylem sap composed of - Answers-water & minerals transported in xylem vessels
What is root pressure? - Answers-- when roots exert slight upward force on xylem sap by actively
pumping minerals into the xylem; water follows by osmosis
- Root pressure is enough force xylem sap up a few meters
what is transpiration in relation to xylems - Answers-•-Transpiration is the loss of water from leaves •
- (1) Water exit leaves through stomata (singular stoma)
, - then Water diffuses out of open stoma because outside air is usually drier than inside leaf. •
- which then creates a vacuum inside leaf.
- requires no energy from the tree
Is water cohesive or adhesive? - Answers-both.
cohesive: because of hydrogen bonding which causes molecules to stick together
adhesive: because it sticks to other surfaces
what within the xylem forms continuous strings from leaves to roots? - Answers-Cohering water
molecules
what allows water to be sucked up towards the leaves? - Answers-both the vacuum created by water
loss in leaves and the cohesion of water
whats does adhesions aid with in the xylem - Answers-helps counteract the downward pull of gravity in
xylem walls
What do guard cells do? - Answers-- control transpiration
- since during dry conditions plants must retain water meaning they need to stop loosing water through
transpiration
what acquires nutrients from air water and soil - Answers-plants
what is 96% of plants' dry weight? - Answers-- organic carbon-containing compounds
how does a plant get carbon? - Answers-carbon comes from CO2 absorbed by plant leaves & integrated
into organic compounds (e.g., glucose) by photosynthesis
what do plants get from soil? - Answers-- water
- minerals
- some O2
what part of roots controls solute uptake? - Answers-The plasma membranes
what must solutes move through to reach the water conducting xylem tissue at the center of the root -
Answers-must move through root epidermis & cortex
- this process involves passage across plasma membranes of root cells
plasma membranes are - Answers-selectively permeable, allowing entry of needed minerals and keeping
out unneeded or toxic substances
two possible routes to a plants xylem - Answers-1) intracellular
2) Extracellular
,intracellular route to xylem is when... - Answers-water & solutes cross plasma membrane of root hair,
travel through passages (plasmodesmata) between cells to xylem
the extacellular route to xylem is when... - Answers-solution moves within cell walls and extracellular
spaces; does not cross any plasma membranes until it hits the Casparian strip
What is the Casparian Strip and what does it do - Answers-- a continuous waxy barrier that stops water
and solutes from entering the xylem through cell walls
- forces water & solutes to cross a plasma membrane into an endodermal cell (the ring of cells around a
vascular bundle)
- this plasma membrane regulates mineral uptake for the the intercellular route.
what pulls water up xylem vessels - Answers-Transcription
what is Xylem sap composed of - Answers-water & minerals transported in xylem vessels
What is root pressure? - Answers-- when roots exert slight upward force on xylem sap by actively
pumping minerals into the xylem; water follows by osmosis
- Root pressure is enough force xylem sap up a few meters
what is transpiration in relation to xylems - Answers-•-Transpiration is the loss of water from leaves •
- (1) Water exit leaves through stomata (singular stoma)
, - then Water diffuses out of open stoma because outside air is usually drier than inside leaf. •
- which then creates a vacuum inside leaf.
- requires no energy from the tree
Is water cohesive or adhesive? - Answers-both.
cohesive: because of hydrogen bonding which causes molecules to stick together
adhesive: because it sticks to other surfaces
what within the xylem forms continuous strings from leaves to roots? - Answers-Cohering water
molecules
what allows water to be sucked up towards the leaves? - Answers-both the vacuum created by water
loss in leaves and the cohesion of water
whats does adhesions aid with in the xylem - Answers-helps counteract the downward pull of gravity in
xylem walls
What do guard cells do? - Answers-- control transpiration
- since during dry conditions plants must retain water meaning they need to stop loosing water through
transpiration
