UVIC BIO 150 Final Exam 1
Questions And 100% Correct Answers
Top Rated A+
what is transpiration in relation to xylems
•-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?
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?
Cohering water molecules
what allows water to be sucked up towards the leaves?
,both the vacuum created by water loss in leaves and the cohesion of
water
whats does adhesions aid with in the xylem
helps counteract the downward pull of gravity in xylem walls
What do guard cells do?
- control transpiration
- since during dry conditions plants must retain water meaning they
need to stop loosing water through transpiration
- the cells open and close in order to control loss of water through the
stomata
why do gaurd cells open during the day
to allow CO2 to enter leaf and fuel photosynthesis
why do guard cells close during the night?
to conserve water when there is no light to power photosynthesis
What does Pholem do?
- transports sugars
- conducts phloem sap
- Sugar must be transported from sugar sources ( leaves) to sugar sinks
( parts of plant that are growing)
phloem sap
a mixture of sugar, nutrients, and water that flows through phloem
vessels in a plant
, Sugar sources are
- organs that are netproducers of sugar, e.g., leaves
sugar sinks
organs that are net consumers, e.g. parts of plant that are growing
steps of the pressure flow mechanism
1. Sugar is loaded into phloem from a photosynthetic cell (by active
transport)
2. High solute concentration draws water into tube by osmosis.
3. Inward flow of water raises water pressure at the source end of the
phloem tube d. At the sink, sugar leaves the phloem
4. & water follows by osmosis which is lowering water pressure.
This pressure difference generates flow of phloem sap from source to
sink organs
what force feeds aphids
- Pressure in phloem
- Aphids filter out sugars and excrete water droplet.
how many essential nutrients do plants require?
- 17 essential nutrients
-9 are macro nutrients
how does a plant get carbon?
Questions And 100% Correct Answers
Top Rated A+
what is transpiration in relation to xylems
•-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?
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?
Cohering water molecules
what allows water to be sucked up towards the leaves?
,both the vacuum created by water loss in leaves and the cohesion of
water
whats does adhesions aid with in the xylem
helps counteract the downward pull of gravity in xylem walls
What do guard cells do?
- control transpiration
- since during dry conditions plants must retain water meaning they
need to stop loosing water through transpiration
- the cells open and close in order to control loss of water through the
stomata
why do gaurd cells open during the day
to allow CO2 to enter leaf and fuel photosynthesis
why do guard cells close during the night?
to conserve water when there is no light to power photosynthesis
What does Pholem do?
- transports sugars
- conducts phloem sap
- Sugar must be transported from sugar sources ( leaves) to sugar sinks
( parts of plant that are growing)
phloem sap
a mixture of sugar, nutrients, and water that flows through phloem
vessels in a plant
, Sugar sources are
- organs that are netproducers of sugar, e.g., leaves
sugar sinks
organs that are net consumers, e.g. parts of plant that are growing
steps of the pressure flow mechanism
1. Sugar is loaded into phloem from a photosynthetic cell (by active
transport)
2. High solute concentration draws water into tube by osmosis.
3. Inward flow of water raises water pressure at the source end of the
phloem tube d. At the sink, sugar leaves the phloem
4. & water follows by osmosis which is lowering water pressure.
This pressure difference generates flow of phloem sap from source to
sink organs
what force feeds aphids
- Pressure in phloem
- Aphids filter out sugars and excrete water droplet.
how many essential nutrients do plants require?
- 17 essential nutrients
-9 are macro nutrients
how does a plant get carbon?
