Biol 186 UVIC Midterm 1 Rossi's -Questions with Correct Answers/ 100%
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How does the ascent of water in a plant take place? - ✔✔Diffusion - short distances
Root Pressure - Pushed upward from roots
Capillary Action - Cohesion and Adhesion fight gravity
Suction Pump - Pulled from roots by leaves.
What does ψ (psi) represent? - ✔✔Water Potential - Predicts which direction water will
flow.
Water moves from higher ψ to lower ψ.
Water potential is given as the equation: ψ = ψp + ψs
What is ψp, and what does it mean when it is positive/negative?
What is ψs, and what does it mean when it is zero/negative? - ✔✔ψp is pressure potential.
When it is positive the solution is compressed, when it is negative the solution is stretched
(under pressure).
ψs is solute/osmotic potential. When it is zero it is pure water, when it is negative solutes
are present.
What is the term used when a plant cell is in surroundings where there is a tendency for
water to leave? - ✔✔Flaccid. (Limp)
What is it called when a cell loses water which results in the plasma membrane pulling away
from the cell wall? - ✔✔Plasmolysis
What is the term for when cells have greater solute concentration than surroundings,
causing water to enter the cell? - ✔✔Turgid (Very rigid)
, What is short distance transport called?
What are the 3 routes for this? - ✔✔Lateral Transport.
Transmembrane Route - repeated crossings of plasma membrane
Symplast - one crossing of plasma membrane
Apoplast
What are 4 routes for long distance transport? - ✔✔Apoplastic Route
Symplastic Route
Transmembrane Route
The Endodermis
What is Bulk Flow? - ✔✔Movement of a fluid driven by pressure.
-root pressure and negative pressure
What drives the Cohesion-tension hypothesis?
What are the 3 key elements? - ✔✔Transportation.
Water moves down a potential gradient.
Water column in xylem is under tension.
Weight of water column is supported by cohesion among water molecules and adhesion to
the xylem walls.
Why are bubbles a serious problem for plants? - ✔✔Xylem water columns have to be
continuous for the cohesion-tension mechanism to work.
What are 2 reasons water columns break? - ✔✔Dissolved gases can form bubbles when
frozen xylem water thaws.
Dry soil can hold water so tightly that the tensile strength of water is exceeded.
pass/ Expert Verified
How does the ascent of water in a plant take place? - ✔✔Diffusion - short distances
Root Pressure - Pushed upward from roots
Capillary Action - Cohesion and Adhesion fight gravity
Suction Pump - Pulled from roots by leaves.
What does ψ (psi) represent? - ✔✔Water Potential - Predicts which direction water will
flow.
Water moves from higher ψ to lower ψ.
Water potential is given as the equation: ψ = ψp + ψs
What is ψp, and what does it mean when it is positive/negative?
What is ψs, and what does it mean when it is zero/negative? - ✔✔ψp is pressure potential.
When it is positive the solution is compressed, when it is negative the solution is stretched
(under pressure).
ψs is solute/osmotic potential. When it is zero it is pure water, when it is negative solutes
are present.
What is the term used when a plant cell is in surroundings where there is a tendency for
water to leave? - ✔✔Flaccid. (Limp)
What is it called when a cell loses water which results in the plasma membrane pulling away
from the cell wall? - ✔✔Plasmolysis
What is the term for when cells have greater solute concentration than surroundings,
causing water to enter the cell? - ✔✔Turgid (Very rigid)
, What is short distance transport called?
What are the 3 routes for this? - ✔✔Lateral Transport.
Transmembrane Route - repeated crossings of plasma membrane
Symplast - one crossing of plasma membrane
Apoplast
What are 4 routes for long distance transport? - ✔✔Apoplastic Route
Symplastic Route
Transmembrane Route
The Endodermis
What is Bulk Flow? - ✔✔Movement of a fluid driven by pressure.
-root pressure and negative pressure
What drives the Cohesion-tension hypothesis?
What are the 3 key elements? - ✔✔Transportation.
Water moves down a potential gradient.
Water column in xylem is under tension.
Weight of water column is supported by cohesion among water molecules and adhesion to
the xylem walls.
Why are bubbles a serious problem for plants? - ✔✔Xylem water columns have to be
continuous for the cohesion-tension mechanism to work.
What are 2 reasons water columns break? - ✔✔Dissolved gases can form bubbles when
frozen xylem water thaws.
Dry soil can hold water so tightly that the tensile strength of water is exceeded.
