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WorksheetsBiology Exam 4: Ch 29
Total questions: 51
Worksheet time: 26mins
How might roots react when they encounter a region of the soil that is low in nitrates?
produce additional root hairs to facilitate nitrate absorption
increase mycorrhizal associations so as to increase nitrate absorption
branch extensively so as to maximize the ability to absorb whatever nitrates are available
produce additional proteins for transporting and assimilating the available nitrates
minimize branching
The proton pump __________.
pumps H+ out of the cell, creating membrane potential
provides energy for active transport
generates energy by producing ATP
pumps H+ into the cell
moves H+ and nitrates into the cell
A plant cell placed in a solution with a higher water potential will __________.
gain water and become turgid
lose water and plasmolyze
gain water and plasmolyze
lose water and plasmolyze
lose water and become turgid
The water potential of a cell is defined by the equation Ψ = ΨS + ΨP. Which statement is true?
ΨS may be either positive or negative.
ΨP may be either positive or negative.
ΨS is always positive.
ΨS is always greater than ΨP.
All of the choices are correct.
A cell has a pressure potential of 0 and a solute potential of −0.7 MPa. What is its water potential?
−0.7 MPa
−0.23 MPa
0 MPa
between 0 and −0.7 MPa
+0.7 MPa
If pure water is separated from a 0.1 M solution in an open, U-shaped tube by a membrane impermeable to the solute, what will happen?
All the water will diffuse to the solution side.
Solute in the solution will diffuse to the pure water side until equilibrium is reached.
Water will move to the 0.1 M solution side until the concentrations are equal on both sides of the membrane.
Water will diffuse toward the solution side until a piston pushes it back at an equal rate.
Water will diffuse to the solution side until the pressure potential due to a higher water column is equal, but opposite in sign, to the osmotic potential.
Which is true for a plant that is wilting?
Root hair cells will have a positive pressure potential.
Mesophyll cells will have a positive pressure potential.
The pressure potential in endodermal cells will be positive.
The pressure potential in the xylem will be more negative than in a turgid plant.
The pressure potential in guard cells will be high to keep them closed.
In a turgid cell, __________.
ΨP is 0
ΨP < 0
Ψ = 0
ΨS is always positive
Ψ = ΨS
Water molecules cross a plasma membrane of a plant cell due to __________.
diffusion
aquaporins
increases in cytoplasmic Ca2+
transport proteins
All of the choices are correct.
The cytoplasmic continuum including the cytosol of all living cells in a plant is the __________.
Casparian strip
apoplast
cell wall
symplast
aquaporin
The continuum of cell walls connecting neighboring cells is defined as the __________.
apoplast
symplast
Casparian strip
plasmodesmata
aquaporin
Which of the cells below are involved with bulk flow?
tracheids, vessels, and plasmodesmata
tracheids, vessels, and sieve tubes
tracheids, vessels, and guard cells
tracheids, plasmodesmata, and sieve tubes
guard cells, vessels, and sieve tubes
Soil can easily become deficient in __________, because these ions are negatively charged and do not stick to negatively charged soil particles.
magnesium
nitrate
ammonium
potassium
calcium
The particles in soil are important because they __________.
fill spaces and keep oxygen out of the soil
eliminate spaces for air and facilitate drainage
supply humus needed by plants
are composed of nitrogen needed by plants
are charged and hold ions needed by plants
Fertilizers are usually enriched in __________.
iron, manganese, and zinc
calcium and boron
nitrogen, phosphorus, and potassium
molybdenum, copper, and magnesium
all essential nutrients
Why do farmers need to be concerned with soil pH?
The pH level of soil affects anion exchange and influences the chemical form of minerals.
The pH level of soil affects water levels.
The pH level of soil affects cation exchange and influences the chemical availability of minerals.
Plants may turn blue if the pH is too high.
None of the choices is correct.
At low soil pH levels (5 or less), what can happen?
Cation exchange will be enhanced, causing the plants to grow faster.
Absorption of negatively charged ions is enhanced, causing the plants to grow faster.
Absorption of calcium is enhanced, but iron is unavailable.
Plant roots are eaten away by the acidic soil.
Toxic aluminum ions become more available, stunting the plant's growth.
The biological process that produces 96% of the dry mass of a plant is called __________.
respiration
cation exchange
oxidation
photosynthesis
transpiration
Which substance does a plant obtain from the air?
magnesium
nitrogen
water
carbon
All of the choices are correct.
A botanist claims to have discovered a new macronutrient required for plant growth. Most of this scientist's colleagues are skeptical of her claim. Why might they consider it unlikely?
All the nutrients required for plant growth have already been found.
Any nutrient needed in large amounts (macronutrient) has probably been identified already.
Plants manufacture their own macronutrients.
Plants need thousands of nutrients; a new one is not significant.
It is very difficult to prove that a plant needs a certain nutrient.
If a plant's leaves are yellowing, it may be that the plant is deficient in the elements needed to make chlorophyll, one of which is __________.
molybdenum
copper
phosphorus
magnesium
sulfur
If a plant is deficient in __________, it will not be able to make DNA.
phosphorus
sulfur
magnesium
iron
manganese
If you had to supply one nutrient to a plant, which would be needed in the smallest amount?
sulfur
iron
nitrogen
potassium
phosphorus
Which is true regarding mineral deficiency symptoms in plants?
Deficiency symptoms of freely moving nutrients will show up first in younger organs.
Symptoms of mineral deficiency always show up in older leaves first.
Growing tissues would show signs of mineral deficiency of mobile nutrients after older tissues.
Symptoms always show up in younger leaves first.
Deficiency symptoms of immobile nutrients will show up first in older organs.
When you add "plant food" to your potted geraniums, you are actually providing the plant with __________.
complex carbohydrates
vitamins and amino acids
sugars
minerals
All of the choices are correct.
What supplies the energy for most of the microorganisms in the rhizosphere?
mycorrhizae
plants
earthworms
soil bacteria
nitrogen-fixing bacteria
Nitrogen fixation is __________.
performed by fungus inhabiting root nodules
absorbing N2 from the soil
using nitrogen to build molecules such as proteins and nucleic acids
recycling nitrogen from organic matter in the soil
converting nitrogen in the air to a form usable by plants
The enzyme that catalyzes the conversion of atmospheric nitrogen to ammonia is __________.
hydrogenase
leghemoglobin
nitrogenase
rubisco
rhizobium
Legumes (members of the pea family) have roots with swellings called nodules that __________.
increase the surface area for water uptake
form fungal hyphae
produce antibiotics that protect the plant from soil bacteria
provide a steady supply of sugar to the host plant
contain nitrogen-fixing bacteria
In root nodules, the mutualistic association between legumes and bacteria, the plants provide __________, and the bacteria provide __________.
carbohydrates … fixed nitrogen
carbohydrates … nitrogen gas
ATP … nitrogen gas
amino acids … ATP
an aerobic environment … fixed nitrogen
Mycorrhizae develop __________.
when soil is too compact and lacks sufficient air spaces
in plants such as mistletoe that parasitize other plants
between roots and beneficial fungi
to control the evaporation of water from leaves
when nutrients are required by plants in relatively small amounts
What is true of mycorrhizae?
Arbuscular mycorrhizae do not have a dense mantle ensheathing roots.
Ectomycorrhizae are found in many crop plants such as wheat and maize.
The fungal hyphae of ectomycorrhizae form arbuscules.
Arbuscular mycorrhizae penetrate the cytoplasm of root cells.
None of the choices is correct.
By trapping insects, carnivorous plants obtain __________, which they need __________.
phosphorus … to make protein
nitrogen … to make sugar
sugars … because they can't make enough in photosynthesis
water … because they live in dry soil
nitrogen … to make protein
The greatest increase in surface area for absorption in the root is due to __________.
root hairs
root nodules
formation of root nodules
mycorrhizae
branch roots
The last thing all water and solute molecules pass through before they enter the vascular system of roots and move upward to the leaves is __________.
a stele
an epidermal cell
an endodermal cell
a root hair cell
a stoma
A botanist discovered a mutant plant that is unable to produce the material that forms the Casparian strip. This plant is __________.
unable to fix nitrogen
unable to transport water or solutes to the leaves
unable to lose water by transpiration
unable to control the movement of water and solutes into the root
able to exert greater root pressure than normal plants
In a plant root, the one cell type in which water cannot move via the apoplast is the __________.
cortex
endodermis
vascular tissues
epidermis
pericycle
A friend of yours has a terrarium on her windowsill containing various houseplants. She wonders why the glass is often fogged with water droplets. What would is the cause of the droplets?
photosynthesis
adhesion
root pressure
pressure flow
transpiration
Which conditions will result in the fastest transport through the xylem in a tree, assuming adequate water supply in the roots?
phloem transport being in the opposite direction from the xylem transport
positive pressure potential in the xylem
negative pressure potential in the leaf mesophyll
positive pressure potential in the mesophyll
What keeps the force of gravity from overcoming transpirational pull?
movement of water toward a sugar sink
the Casparian strip blocking water molecules from moving out
cohesion and adhesion of water molecules
upward pressure from the roots
high water pressure in the leaves
Normally when an aphid feeds by puncturing plant tissues, it does not have to suck the sap out. If an aphid, however, inserted its feeding tube in the wrong place, the fluid in the aphid's guts could be sucked out through the feeding tube. What could explain this phenomenon?
The aphid pierced the Casparian strip.
The aphid punctured xylem cells.
The aphid punctured a root nodule.
The aphid punctured a sieve tube cell.
The aphid punctured a stoma.
During winter, tree sap can sometimes freeze, and cavitation (the formation of an air pocket) may occur. Which mechanism of sap transport would you expect to be most immediately affected by cavitation?
symplast function
active transport
root pressure
transpiration
pressure flow (mass flow)
What is the ultimate source of energy that moves water upward in the trunk of a tree?
contraction of xylem cells
evaporation of water by the sun
osmotic changes caused by alterations in salt content
breakdown and release of energy of sugar molecules
pressure exerted by root cells
The rate of transpiration is expected to be greatest on a __________ day.
cool and moist
cool and dry
warm and dry
warm and moist
windy and cool
What process contributes directly to the turgor pressure that opens and closes stomata?
active transport
respiration
transpiration
guttation
plasmolysis
Stomata open during the day in response to __________.
the production of abscisic acid
increased temperatures
blue light triggering the uptake of K+ by guard cells
blue light triggering the efflux of K+ from guard cells
increased CO2 levels
Which describes how some plants are adapted to arid environments?
They have evolved alternatives to the Calvin cycle.
They lose more water to transpiration than C3 plants.
They can leave their stomata open even on very hot, dry days.
They can liberate carbon dioxide stored in intermediate molecules during the night and fix it during the day even when stomata are closed.
All of the choices are correct.
In an apple tree that is producing sugars, sugar might flow from __________ to __________.
a developing apple … a mature leaf
a leaf … a developing apple
a growing shoot tip … a leaf
a growing shoot tip … the trunk
the trunk … a leaf
Cells that are specialized for the transport of sugar between apoplast and symplast are __________ cells.
aquaporin
companion
mesophyll
guard
bundle sheath
When referring to phloem transport, the "sink" in roots is created by __________.
the absorption of water from the soil through epidermal cells
the active transport of mineral ions into xylem cells
the osmosis of water into xylem cells
the active transport of sugars from phloem to cortex cells
All of the choices are correct.
When sugar is transported in plants, __________.
sugar always moves upward from roots to leaves
leaves are always sugar sinks and roots are always sugar sources
leaves are always sugar sources and roots are always sugar sinks
leaves may be sinks or sources, but roots are always sinks
None of the choices is correct.
