BZ 440 EXAM I QUESTIONS ANSWERED CORRECTLY LATEST UPDATE
2026
Name 4 plant organs - Answers Root, stem, leaf, flower
Name 7 plant organelles and give a function for each - Answers Nucleus (gene
expression, cell management), vacuole (storage, degradation, recycling), ER (protein
and fat synthesis), Golgi (protein and fat modification and shipping), oxysome
(detoxification, gluconeogenesis), chloroplast (photosynthesis), mitochondrion
(respiration)
Name 3 other large cellular structures in plant cells, and function - Answers
Ribosomes (protein synthesis), cell wall (sturdiness), cytoskeleton (sturdiness,
movement)
What are symplast and apoplast? Where do plasmodesmata come in? - Answers
Symplast is collective space in organ within cell membranes, connected via
plasmadesmata. Apoplast is collective space in organ outside cell membranes (cell
walls and xylem)
What are xylem and phloem and are they symplast or apoplast? - Answers Xylem is
vascular tissue that brings water and nutrients from root to shoot; part of apoplast.
Phloem is vascular tissue that brings water and sugars and remobilized nutrients from
mature leaves (source organs) to other plant parts (sinks); part of symplast.
What is osmosis? - Answers Passive movement of water across membranes
What is meant with hypotonic, hypertonic and isotonic? - Answers Relative total
solute concentration on either side of a membrane. Isotonic = equal concentrations on
both sides. Hypo/hypertonic: one is lower (hypo) relative to the other side (hyper).
What is water potential and what are its two main components? - Answers The
capacity to attract water, due to either the solutes present (solute potential component)
or the pressure present (pressure potential component). Higher solute concentration
means more negative solute potential, so higher capacity to attract water. Lower
pressure means more negative (or less positive) pressure potential, so higher capacity
to attract water. Total water potential = solution potential plus pressure potential.
How does water potential change as water moves into, up and out of a plant? For each
membrane step, is the water movement solute driven or pressure driven? - Answers It
goes down. Water always moves to the lowest overall water potential. Into roots:
solute-driven osmosis. From root cells into xylem: pressure-driven osmosis. Within
xylem from root to shoot: bulk flow, pressure driven (sucked up by transpiration).
From leaf xylem into leaf cells: solute driven osmosis. Out of leaf cells into air:
pressure driven osmosis.
If a cell's water potential is -1.0 MPa and its osmotic potential is -1.5 MPa, what is the
turgor pressure? - Answers +0.5 MPa (- 1.0 - (-1.5) = +0.5)
Of two sibling plants, one is mildly drought stressed and the other not. After a while
you measure osmotic potential. Which one would you expect to give the most
negative value, and why? Is this adaptation or acclimation? - Answers The drought
stressed one. This is acclimation. It has accumulated more solutes as osmotic
adjustment.
What technique can you use to measure that osmotic potential? - Answers
Psychrometer (freeze leaf disk to break open cells and remove turgor pressure, then
measure water potential)
Which will have the most negative water potential: a fresh water alga or an oceanic
alga? Why? Is this adaptation or acclimation? - Answers The oceanic alga. It has
2026
Name 4 plant organs - Answers Root, stem, leaf, flower
Name 7 plant organelles and give a function for each - Answers Nucleus (gene
expression, cell management), vacuole (storage, degradation, recycling), ER (protein
and fat synthesis), Golgi (protein and fat modification and shipping), oxysome
(detoxification, gluconeogenesis), chloroplast (photosynthesis), mitochondrion
(respiration)
Name 3 other large cellular structures in plant cells, and function - Answers
Ribosomes (protein synthesis), cell wall (sturdiness), cytoskeleton (sturdiness,
movement)
What are symplast and apoplast? Where do plasmodesmata come in? - Answers
Symplast is collective space in organ within cell membranes, connected via
plasmadesmata. Apoplast is collective space in organ outside cell membranes (cell
walls and xylem)
What are xylem and phloem and are they symplast or apoplast? - Answers Xylem is
vascular tissue that brings water and nutrients from root to shoot; part of apoplast.
Phloem is vascular tissue that brings water and sugars and remobilized nutrients from
mature leaves (source organs) to other plant parts (sinks); part of symplast.
What is osmosis? - Answers Passive movement of water across membranes
What is meant with hypotonic, hypertonic and isotonic? - Answers Relative total
solute concentration on either side of a membrane. Isotonic = equal concentrations on
both sides. Hypo/hypertonic: one is lower (hypo) relative to the other side (hyper).
What is water potential and what are its two main components? - Answers The
capacity to attract water, due to either the solutes present (solute potential component)
or the pressure present (pressure potential component). Higher solute concentration
means more negative solute potential, so higher capacity to attract water. Lower
pressure means more negative (or less positive) pressure potential, so higher capacity
to attract water. Total water potential = solution potential plus pressure potential.
How does water potential change as water moves into, up and out of a plant? For each
membrane step, is the water movement solute driven or pressure driven? - Answers It
goes down. Water always moves to the lowest overall water potential. Into roots:
solute-driven osmosis. From root cells into xylem: pressure-driven osmosis. Within
xylem from root to shoot: bulk flow, pressure driven (sucked up by transpiration).
From leaf xylem into leaf cells: solute driven osmosis. Out of leaf cells into air:
pressure driven osmosis.
If a cell's water potential is -1.0 MPa and its osmotic potential is -1.5 MPa, what is the
turgor pressure? - Answers +0.5 MPa (- 1.0 - (-1.5) = +0.5)
Of two sibling plants, one is mildly drought stressed and the other not. After a while
you measure osmotic potential. Which one would you expect to give the most
negative value, and why? Is this adaptation or acclimation? - Answers The drought
stressed one. This is acclimation. It has accumulated more solutes as osmotic
adjustment.
What technique can you use to measure that osmotic potential? - Answers
Psychrometer (freeze leaf disk to break open cells and remove turgor pressure, then
measure water potential)
Which will have the most negative water potential: a fresh water alga or an oceanic
alga? Why? Is this adaptation or acclimation? - Answers The oceanic alga. It has
