Name: 
 

Unit 8B Plants II


Multiple Choice
Identify the choice that best completes the statement or answers the question.
 

 1. 
You are studying a plant from the arid southwestern United States. Which of the following adaptations is least likely to have evolved in response to water shortages?
a.
closing the stomata during the hottest time of the day
b.
development of large leaf surfaces to absorb water
c.
formation of a fibrous root system spread over a large area
d.
mycorrhizae associated with the root system
e.
a thick waxy cuticle on the epidermis
 

 2. 
An evolutionary adaptation that increases exposure of a plant to light in a dense forest is
a.
closing of the stomata.
b.
lateral buds.
c.
apical dominance.
d.
absence of petioles.
e.
intercalary meristems.
 

 3. 
A person working with plants may remove apical dominance by doing which of the following?
a.
pruning
b.
deep watering of the roots
c.
fertilizing
d.
transplanting
e.
feeding the plants nutrients
 

 4. 
What effect does "pinching back" have on a houseplant?
a.
increases apical dominance
b.
inhibits the growth of lateral buds
c.
produces a plant that will grow taller
d.
produces a plant that will grow fuller
e.
increases the flow of auxin down the shoot
 

 5. 
Land plants are composed of all the following tissue types except
a.
mesodermal.
b.
epidermal.
c.
meristematic.
d.
vascular.
e.
ground tissue.
 

 6. 
Vascular plant tissue includes all of the following cell types except
a.
vessel elements.
b.
sieve cells.
c.
tracheids.
d.
companion cells.
e.
cambium cells.
 
 
Use the answers below to answer the following questions. Each answer may be used once, more than once, or not at all.

A.parenchyma
B.collenchyma
C.sclerenchyma
D.tracheids
E.sieve cells
 

 7. 
long, thin tapered cells with lignified cell walls that function in support and permit water to flow through pits
a.
A
b.
B
c.
C
d.
D
e.
E
 

 8. 
the least specialized plant cells, which serve general metabolic, synthetic, and storage functions
a.
A
b.
B
c.
C
d.
D
e.
E
 

 9. 
cells with unevenly thickened primary walls that support still-elongating parts of the plant
a.
A
b.
B
c.
C
d.
D
e.
E
 

 10. 
mature cells without protoplasts with thick, lignified secondary walls that may or may not function in transport
a.
A
b.
B
c.
C
d.
D
e.
E
 

 11. 
Which of the following is not a characteristic of parenchyma cells?
a.
thin primary walls
b.
flexible primary walls
c.
lack of specialization
d.
lack of secondary walls
e.
little metabolism and synthesis
 

 12. 
Which of the following tissues is incorrectly matched with its characteristics?
a.
collenchyma-uniformly thick-walled supportive tissue
b.
epidermis-protective outer covering of plant body
c.
sclerenchyma-heavily lignified secondary walls
d.
meristematic tissue-undifferentiated tissue capable of cell division
e.
parenchyma-thin-walled, loosely packed, unspecialized cells
 

 13. 
The fiber cells of plants are a type of
a.
parenchyma.
b.
sclerenchyma.
c.
collenchyma.
d.
meristematic cell.
e.
phloem
 

 14. 
The vascular bundle in the shape of a single central cylinder in a root is called the
a.
cortex.
b.
stele.
c.
endodermis.
d.
periderm.
e.
pith.
 

 15. 
One important difference between the anatomy of roots and the anatomy of leaves is that
a.
only leaves have phloem and only roots have xylem.
b.
the cells of roots have cell walls and leaf cells do not.
c.
a waxy cuticle covers leaves but is absent in roots.
d.
vascular tissue is found in roots but is absent from leaves.
e.
leaves have epidermal tissue but roots do not.
 

 16. 
The photosynthetic cells in the interior of a leaf are what kind of cells?
a.
parenchyma
b.
collenchyma
c.
sclerenchyma
d.
phloem
e.
endodermis
 

 17. 
A student examining leaf cross sections under a microscope finds many loosely packed cells with relatively thin cell walls. The cells have numerous chloroplasts. What type of cells are these?
a.
parenchyma
b.
xylem
c.
endodermis
d.
collenchyma
e.
sclerenchyma
 

 18. 
The best word to describe the growth of plants in general is
a.
perennial.
b.
weedy.
c.
indeterminate.
d.
derivative.
e.
primary.
 

 19. 
A friend has discovered a new plant and brings it to you to classify. The plant has the following characteristics: a taproot system with growth rings evident in cross section and a layer of bark around the outside. Which of the following best describes the new plant?
a.
herbaceous eudicot
b.
woody eudicot
c.
woody monocot
d.
herbaceous monocot
e.
woody annual
 

 20. 
The driving force that pushes the root tip through the soil is due primarily to
a.
continuous cell division in the root cap at the tip of the root.
b.
continuous cell division just behind the root cap in the center of the apical meristem.
c.
elongation of cells behind the root apical meristem.
d.
A and B only.
e.
A, B, and C.
 

 21. 
Shoot elongation in a growing bud is due primarily to
a.
cell division at the shoot apical meristem.
b.
cell elongation directly behind the shoot apical meristem.
c.
cell division localized in each internode.
d.
cell elongation localized in each internode.
e.
A and B only.
 

 22. 
Axillary buds
a.
are initiated by the cork cambium.
b.
develop from meristematic cells left by the apical meristem.
c.
are composed of a series of internodes lacking nodes.
d.
grow immediately into shoot branches.
e.
do not form a vascular connection with the primary shoot.
 
 
The following question is based on parts of a growing primary root.
I.root cap
II.zone of elongation
III.zone of cell division
IV.zone of cell maturation
V.apical meristem
 

 23. 
Which of the following is the correct sequence from the growing tips of the root upward?
a.
I, II, V, III, IV
b.
III, V, I, II, IV
c.
II, IV, I, V, III
d.
IV, II, III, I, V
e.
I, V, III, II, IV
 

 24. 
Which of the following is incorrectly paired with its structure and function?
a.
sclerenchyma-supporting cells with thick secondary walls
b.
periderm-protective coat of woody stems and roots
c.
pericycle-waterproof ring of cells surrounding the central stele in roots
d.
mesophyll-parenchyma cells functioning in photosynthesis in leaves
e.
ground meristem-primary meristem that produces the ground tissue system
 

 25. 
Which of the following illustrates the idea that the fate of a cell is a direct result of its position?
a.
Some root epidermal cells form hairs; others do not.
b.
Floating leaves of Cabomba have a different shape than submerged leaves.
c.
Some shoot epidermal cells form stomata; others do not.
d.
A and C only
e.
A, B, and C
 

 26. 
Which of the following root tissues gives rise to lateral roots?
a.
endodermis
b.
phloem
c.
cortex
d.
epidermis
e.
pericycle
 
 
The following questions are based on the drawing of root or stem cross sections shown in the figure below.

nar003-1.jpg
 

 27. 
A woody eudicot is represented by
a.
I only.
b.
II only.
c.
III only.
d.
IV only.
e.
both I and III.
 

 28. 
A monocot stem is represented by
a.
I only.
b.
II only.
c.
III only.
d.
IV only.
e.
both I and III.
 

 29. 
A leaf primordium is initiated as a small mound of tissue on the flank of a dome-shaped shoot apical meristem. The earliest physical evidence of the site of a newly forming leaf primordium would be
a.
development of chloroplasts in a surface cell of the shoot apical meristem.
b.
cell division in the shoot apical meristem with the newly forming walls perpendicular to the surface of the meristem.
c.
pre-prophase bands parallel to the surface of the meristem in subsurface cells of the shoot apical meristem.
d.
elongation of epidermal cells perpendicular to the surface of the shoot apical meristem.
e.
formation of stomata in the epidermal layer of the shoot apical meristem.
 

 30. 
Pores on the leaf surface that function in gas exchange are called
a.
hairs.
b.
xylem cells.
c.
phloem cells.
d.
stomata.
e.
sclereids.
 

 31. 
All of the following cell types are correctly matched with their functions except
a.
mesophyll-photosynthesis
b.
guard cell-regulation of transpiration
c.
sieve-tube member-translocation
d.
vessel element-water transport
e.
companion cell-formation of secondary xylem and phloem
 

 32. 
As a youngster, you drive a nail in the trunk of a young tree that is 3 meters tall. The nail is about 1.5 meters from the ground. Fifteen years later, you return and discover the tree has grown to a height of 30 meters. The nail is now ____ meters above the ground.
a.
0.5
b.
1.5
c.
3.0
d.
15.0
e.
28.5
 

 33. 
A short branch was cut into three segments as shown in the figure below to root some cuttings. Roots will form at which position(s)?

mc033-1.jpg

a.
A only
b.
A and B
c.
A, B, and C
d.
A, C, and E
e.
A, B, C, D, and E
 

 34. 
What tissue makes up most of the wood of a tree?
a.
primary xylem
b.
secondary xylem
c.
secondary phloem
d.
mesophyll cells
e.
vascular cambium
 

 35. 
The vascular system of a three-year-old eudicot stem consists of
a.
3 rings of xylem and 3 of phloem.
b.
2 rings of xylem and 2 of phloem.
c.
2 rings of xylem and 1 of phloem.
d.
2 rings of xylem and 3 of phloem.
e.
3 rings of xylem and 1 of phloem.
 

 36. 
If you were able to walk into an opening cut into the center of a large redwood tree, when you exit from the middle of the trunk (stem) outward, you would cross, in order,
a.
the annual rings, phloem, and bark.
b.
the newest xylem, oldest phloem, and periderm.
c.
the vascular cambium, oldest xylem, and newest xylem.
d.
the secondary xylem, secondary phloem, and vascular cambium.
e.
the summer wood, bark, and phloem.
 

 37. 
Bark becomes scaly because
a.
the cork cambium stops dividing in certain places.
b.
some cork cells die and slough off while others remain alive.
c.
ray parenchyma supplies only the "ridges" of bark.
d.
cork cambium divides only parallel to the surface, and thus does not increase in circumference.
e.
cork cambium has both ray and fusiform initials.
 

 38. 
Additional vascular tissue produced as secondary growth in a root originates from which cells?
a.
vascular cambium
b.
apical meristem
c.
endodermis
d.
phloem
e.
xylem
 

 39. 
While studying the plant Arabidopsis, a botanist finds that an RNA probe produces colored spots in the sepals of the plant. From this information, what information can be inferred?
a.
The differently colored plants will attract different pollinating insects.
b.
The RNA probe is transported only to certain tissues.
c.
The colored regions were caused by mutations that occurred in the sepals.
d.
The RNA probe is specific to a gene active in sepals.
e.
More research needs to be done on the sepals of Arabidopsis.
 

 40. 
Before differentiation can begin during the processes of plant cell and tissue culture, parenchyma cells from the source tissue must
a.
differentiate into procambium.
b.
undergo dedifferentiation.
c.
increase the number of chromosomes in their nuclei.
d.
enzymatically digest their primary cell walls.
e.
establish a new polarity in their cytoplasm.
 

 41. 
The polarity of a plant is established when
a.
the zygote divides.
b.
cotyledons form at the shoot end of the embryo.
c.
the shoot-root axis is established in the embryo.
d.
the primary root breaks through the seed coat.
e.
the shoot first breaks through the soil into the light as the seed germinates.
 

 42. 
Which of the following would be least likely to affect osmosis in plants?
a.
proton pumps in the membrane
b.
a difference in solute concentrations
c.
receptor proteins in the membrane
d.
aquaporins
e.
a difference in water potential
 

 43. 
Which of the following is not a function of the plasma membrane proton pump?
a.
hydrolyzes ATP
b.
produces a proton gradient
c.
generates a membrane potential
d.
equalizes the charge on each side of a membrane
e.
stores potential energy on one side of a membrane
 

 44. 
Which of the following is an example of osmosis?
a.
flow of water out of a cell
b.
pumping of water into a cell
c.
flow of water between cells
d.
both A and B
e.
both A and C
 

 45. 
The amount and direction of movement of water in plants can always be predicted by measuring which of the following?
a.
air pressure
b.
rainfall
c.
proton gradients
d.
dissolved solutes
e.
water potential (mc045-1.jpg)
 

 46. 
Which of the following is true concerning the water potential of a plant cell?
a.
It is higher than that of air.
b.
It is equal to zero when the cell is in pure water and is turgid.
c.
It is equal to 0.23 MPa.
d.
It becomes higher when K+ is actively moved into the cell.
e.
It becomes lower after the uptake of water by osmosis.
 

 47. 
Your laboratory partner has an open beaker of pure water. By definition, the water potential (mc047-1.jpg) of this water is
a.
not meaningful, because it is an open beaker and not plant tissue.
b.
a negative number set by the volume of the beaker.
c.
a positive number set by the volume of the beaker.
d.
equal to the atmospheric pressure.
e.
zero.
 

 48. 
Which of the following has an effect on water potential (mc048-1.jpg) in plants?
a.
air pressure
b.
water-attracting matrices
c.
dissolved solutes
d.
A and C only
e.
A, B, and C
 

 49. 
If mc049-1.jpgP = 0.3 MPa and mc049-2.jpgS = -0.45 MPa, the resulting mc049-3.jpg is
a.
+0.75 MPa.
b.
-0.75 MPa.
c.
-0.15 MPa.
d.
+0.15 MPa.
e.
impossible to calculate with this information.
 

 50. 
The value for mc050-1.jpg in root tissue was found to be -0.15 MPa. If you take the root tissue and place it in a 0.1 M solution of sucrose (mc050-2.jpg = -0.23), net water flow would
a.
be from the tissue into the sucrose solution.
b.
be from the sucrose solution into the tissue.
c.
be in both directions and the concentrations would remain equal.
d.
occur only as ATP was hydrolyzed in the tissue.
e.
be impossible to determine from the values given here.
 

 51. 
Compared to a cell with few aquaporins in its membrane, a cell containing many aquaporins will
a.
have a faster rate of osmosis.
b.
have a lower water potential.
c.
have a higher water potential.
d.
have a faster rate of active transport.
e.
be flaccid.
 

 52. 
Some botanists argue that the entire plant should be considered as a single unit rather than a composite of many individual cells. Which of the following cellular structures cannot be used to support this view?
a.
cell wall
b.
cell membrane
c.
cytosol
d.
tonoplast
e.
symplast
 

 53. 
Which of the following statements about xylem is incorrect?
a.
It conducts material upward.
b.
It conducts materials within dead cells.
c.
It transports mainly sugars and amino acids.
d.
It has a lower water potential than soil does.
e.
No energy input from the plant is required for xylem transport.
 

 54. 
Which of the following would likely not contribute to the surface area available for water absorption from the soil by a plant root system?
a.
root hairs
b.
endodermis
c.
mycorrhizae
d.
fungi associated with the roots
e.
fibrous arrangement of the roots
 

 55. 
Root hairs are most important to a plant because they
a.
anchor a plant in the soil.
b.
store starches.
c.
increase the surface area for absorption.
d.
provide a habitat for nitrogen-fixing bacteria.
e.
contain xylem tissue.
 

 56. 
What is the role of proton pumps in root hair cells?
a.
establish ATP gradients
b.
acquire minerals from the soil
c.
pressurize xylem transport
d.
eliminate excess electrons
e.
A and D only
 

 57. 
In plant roots, the Casparian strip is correctly described by which of the following?
a.
It is located in the walls between endodermal cells and cortex cells.
b.
It provides energy for the active transport of minerals into the stele from the cortex.
c.
It ensures that all minerals are absorbed from the soil in equal amounts.
d.
It ensures that all water and dissolved substances must pass through a cell before entering the stele.
e.
It provides increased surface area for the absorption of mineral nutrients.
 

 58. 
Pine seedlings grown in sterile potting soil grow much slower than seedlings grown in soil from the area where the seeds were collected. This is most likely because
a.
the sterilization process kills the root hairs as they emerge from the seedling.
b.
the normal symbiotic fungi are not present in the sterilized soil.
c.
sterilization removes essential nutrients from the soil.
d.
water and mineral uptake is faster when mycorrhizae are present.
e.
both B and D
 

 59. 
A water molecule could move all the way through a plant from soil to root to leaf to air and pass through a living cell only once. This living cell would be a part of which structure?
a.
the Casparian strip
b.
a guard cell
c.
the root epidermis
d.
the endodermis
e.
the root cortex
 

 60. 
What is the main cause of guttation in plants?
a.
root pressure
b.
transpiration
c.
pressure flow in phloem
d.
plant injury
e.
condensation of atmospheric water
 

 61. 
One is most likely to see guttation in small plants when the
a.
transpiration rates are high.
b.
root pressure exceeds transpiration pull.
c.
preceding evening was hot, windy, and dry.
d.
water potential in the stele of the root is high.
e.
roots are not absorbing minerals from the soil.
 

 62. 
What is the main force by which most of the water within xylem vessels moves toward the top of a tree?
a.
active transport of ions into the stele
b.
atmospheric pressure on roots
c.
evaporation of water through stoma
d.
the force of root pressure
e.
osmosis in the root
 

 63. 
Which of the following has the lowest (most negative) water potential?
a.
soil
b.
root xylem
c.
trunk xylem
d.
leaf cell walls
e.
leaf air spaces
 

 64. 
Transpiration in plants requires all of the following except
a.
adhesion of water molecules to cellulose.
b.
cohesion between water molecules.
c.
evaporation of water molecules.
d.
active transport through xylem cells.
e.
transport through tracheids.
 

 65. 
Which of the following statements about transport in plants is false?
a.
Weak bonding between water molecules and the walls of xylem vessels or tracheids helps support the columns of water in the xylem.
b.
Hydrogen bonding between water molecules, which results in the high cohesion of the water, is essential for the rise of water in tall trees.
c.
Although some angiosperm plants develop considerable root pressure, this is not sufficient to raise water to the tops of tall trees.
d.
Most plant physiologists now agree that the pull from the top of the plant resulting from transpiration is sufficient, when combined with the cohesion of water, to explain the rise of water in the xylem in even the tallest trees.
e.
Gymnosperms can sometimes develop especially high root pressure, which may account for the rise of water in tall pine trees without transpiration pull.
 

 66. 
Active transport would be least important in the normal functioning of which of the following plant tissue types?
a.
leaf transfer cells
b.
stem xylem
c.
root endodermis
d.
leaf mesophyll
e.
root phloem
 

 67. 
Which of the following statements is false concerning the xylem?
a.
Xylem tracheids and vessels fulfill their vital function only after their death.
b.
The cell walls of the tracheids are greatly strengthened with cellulose fibrils forming thickened rings or spirals.
c.
Water molecules are transpired from the cells of the leaves, and replaced by water molecules in the xylem pulled up from the roots due to the cohesion of water molecules.
d.
Movement of materials is by mass flow; materials move owing to a turgor pressure gradient from "source" to "sink."
e.
In the morning, sap in the xylem begins to move first in the twigs of the upper portion of the tree, and later in the lower trunk.
 

 68. 
Guard cells do which of the following?
a.
protect the endodermis
b.
accumulate K+ and close the stomata
c.
contain chloroplasts that import K+ directly into the cells
d.
guard against mineral loss through the stomata
e.
help balance the photosynthesis-transpiration compromise
 

 69. 
All of the following normally enter the plant through the roots except
a.
carbon dioxide.
b.
nitrogen.
c.
potassium.
d.
water.
e.
calcium.
 

 70. 
The water lost during transpiration is an unfortunate side effect of the plant's exchange of gases. However, the plant derives some benefit from this water loss in the form of
a.
evaporative cooling.
b.
mineral transport.
c.
increased turgor.
d.
A and B only
e.
A, B, and C
 

 71. 
Ignoring all other factors, what kind of day would result in the fastest delivery of water and minerals to the leaves of a tree?
a.
cool, dry day
b.
warm, dry day
c.
warm, humid day
d.
cool, humid day
e.
very hot, dry, windy day
 

 72. 
If the guard cells and surrounding epidermal cells in a plant are deficient in potassium ions, all of the following would occur except
a.
photosynthesis would decrease.
b.
roots would take up less water.
c.
phloem transport rates would decrease.
d.
leaf temperatures would decrease.
e.
stomata would be closed.
 

 73. 
The opening of stomata is thought to involve
a.
an increase in the osmotic concentration of the guard cells.
b.
a decrease in the osmotic concentration of the stoma.
c.
active transport of water out of the guard cells.
d.
decreased turgor pressure in guard cells.
e.
movement of K+ from guard cells.
 

 74. 
Which of the following experimental procedures would most likely reduce transpiration while allowing the normal growth of a plant?
a.
subjecting the leaves of the plant to a partial vacuum
b.
increasing the level of carbon dioxide around the plant
c.
putting the plant in drier soil
d.
decreasing the relative humidity around the plant
e.
injecting potassium ions into the guard cells of the plant
 

 75. 
Guard cells are the only cells in the epidermis that contain chloroplasts and can undergo photosynthesis. This is important because
a.
chloroplasts sense when light is available so that guard cells will open.
b.
photosynthesis provides the energy necessary for contractile proteins to flex and open the guard cells.
c.
guard cells will produce the O2 necessary to power active transport.
d.
ATP is required to power proton pumps in the guard cell membranes.
e.
both A and C
 

 76. 
All of the following are adaptations that help reduce water loss from a plant except
a.
transpiration.
b.
sunken stomata.
c.
C4 photosynthesis.
d.
small, thick leaves.
e.
crassulacean acid metabolism.
 

 77. 
Which of the following best explains why CAM plants are not tall?
a.
They would be unable to move water and minerals to the top of the plant during the day.
b.
They would be unable to supply sufficient sucrose for active transport of minerals into the roots during the day or night.
c.
Transpiration occurs only at night, and this would cause a highly negative mc077-1.jpg in the roots of a tall plant during the day.
d.
Since the stomata are closed in the leaves, the Casparian strip is closed in the endodermis of the root.
e.
With the stomata open at night, the transpiration rate would limit plant height.
 

 78. 
As a biologist, it is your job to look for plants that have evolved structures with a selective advantage in dry, hot conditions. Which of the following adaptations would be least likely to meet your objective?
a.
CAM plants that grow rapidly
b.
small, thick leaves with stomata on the lower surface
c.
a thick cuticle on fleshy leaves
d.
large, fleshy stems with the ability to carry out photosynthesis
e.
plants that do not produce abscisic acid and have a short, thick tap root
 

 79. 
Phloem transport of sucrose can be described as going from "source to sink." Which of the following would not normally function as a sink?
a.
growing leaf
b.
growing root
c.
storage organ in summer
d.
mature leaf
e.
shoot tip
 

 80. 
Which of the following is a correct statement about sugar movement in phloem?
a.
Diffusion can account for the observed rates of transport.
b.
Movement can occur both upward and downward in the plant.
c.
Sugar is translocated from sinks to sources.
d.
Only phloem cells with nuclei can perform sugar movement.
e.
Sugar transport does not require energy.
 

 81. 
Phloem transport is described as being from source to sink. Which of the following would most accurately complete this statement about phloem transport as applied to most plants in the late spring? Phloem transports ____ from the ____ source to the ____ sink.
a.
amino acids; root; mycorrhizae
b.
sugars; leaf; apical meristem
c.
nucleic acids; flower; root
d.
proteins; root; leaf
e.
sugars; stem; root
 

 82. 
Water flows into the source end of a sieve tube because
a.
sucrose has diffused into the sieve tube, making it hypertonic.
b.
sucrose has been actively transported into the sieve tube, making it hypertonic.
c.
water pressure outside the sieve tube forces in water.
d.
the companion cell of a sieve tube actively pumps in water.
e.
sucrose has been dumped from the sieve tube by active transport.
 

 83. 
Which one of the following statements about transport of nutrients in phloem is false?
a.
Solute particles can be actively transported into phloem at the source.
b.
Companion cells control the rate and direction of movement of phloem sap.
c.
Differences in osmotic concentration at the source and sink cause a hydrostatic pressure gradient to be formed.
d.
A sink is that part of the plant where a particular solute is consumed or stored.
e.
A sink may be located anywhere in the plant.
 

 84. 
As predicted by the pressure flow hypothesis of translocation in plants, phloem exudates from the severed stylets of aphids near photosynthetic cells are sites of
a.
relatively high hydrostatic pressure.
b.
relatively low hydrostatic pressure.
c.
relatively high concentrations of organic nutrients.
d.
active pumping of sucrose out of the sieve tube.
e.
A and C only
 

 85. 
Plants do not have a circulatory system like that of some animals. If a given water molecule did "circulate" (that is, go from one point in a plant to another and back), it would require the activity of
a.
only the xylem.
b.
only the phloem.
c.
only the endodermis.
d.
both the xylem and the endodermis.
e.
both the xylem and the phloem.
 

 86. 
In the pressure flow hypothesis of translocation, what causes the pressure?
a.
root pressure
b.
the osmotic uptake of water by sieve tubes at the source
c.
the accumulation of minerals and water by the stele in the root
d.
the osmotic uptake of water by the sieve tubes of the sink
e.
hydrostatic pressure in xylem vessels
 

 87. 
Most of the dry weight of a plant is the result of uptake of
a.
water and minerals through root hairs.
b.
water and minerals through mycorrhizae.
c.
CO2 through stomata in leaves.
d.
CO2 and O2 through stomata in leaves.
e.
both A and B
 

 88. 
You are conducting an experiment on plant growth. You take a plant fresh from the soil that weighs 5 kg. Then you dry the plant overnight and determine the dry weight to be 1 kg. Of this dry weight, how much would you expect to be made up of inorganic minerals?
a.
1 gram
b.
5 grams
c.
50 grams
d.
75 grams
e.
1 kg
 

 89. 
In hydroponic culture, what is the purpose of bubbling air into the solute?
a.
to keep dissolved nutrients evenly distributed
b.
to provide oxygen to root cells
c.
to inhibit the growth of aerobic algae
d.
to inhibit the growth of anaerobic bacteria
e.
both C and D
 

 90. 
When performing a mineral nutrition experiment, researchers use water from a glass still. Why is it not a good idea to use regular distilled water from a stainless steel still?
a.
With a steel still, lime deposits from hard water will build up too quickly.
b.
Salts in the water corrode steel more quickly than glass.
c.
Metal ions dissolving off the steel may serve as micronutrients.
d.
A glass still allows the distillation process to be observed.
e.
There is no difference; both kinds of stills produce distilled water.
 

 91. 
Which of the following is of least concern to a researcher in a mineral nutrition experiment?
a.
purity of the chemicals used to make the nutrient solutions
b.
purity of the water used to make the nutrient solutions
c.
chemical inertness of the container used to make and store the nutrient solutions
d.
ability of a laboratory balance to weigh very small quantities of chemicals
e.
medium in which the test seedlings were grown
 

 92. 
Which two elements make up more than 90% of the dry weight of plants?
a.
carbon and nitrogen
b.
oxygen and hydrogen
c.
nitrogen and oxygen
d.
oxygen and carbon
e.
carbon and potassium
 

 93. 
The bulk of a plant's dry weight is derived from
a.
soil minerals.
b.
CO2.
c.
the hydrogen from H2O.
d.
the oxygen from H2O.
e.
the uptake of organic nutrients from the soil.
 

 94. 
What are the three main elements on which plant growth and development depend?
a.
nitrogen; carbon; oxygen
b.
potassium; carbon; oxygen
c.
oxygen; carbon; hydrogen
d.
phosphorus; nitrogen; oxygen
e.
sulfur; nitrogen; phosphorus
 

 95. 
A growing plant exhibits chlorosis of the leaves of the entire plant. The chlorosis is probably due to a deficiency of which of the following macronutrients?
a.
carbon
b.
oxygen
c.
nitrogen
d.
calcium
e.
hydrogen
 

 96. 
Which of the following elements is incorrectly paired with its function in a plant?
a.
nitrogen—component of nucleic acids, proteins, hormones, coenzymes
b.
magnesium—component of chlorophyll; activates many enzymes
c.
phosphorus—component of nucleic acids, phospholipids, ATP, several coenzymes
d.
potassium—cofactor functional in protein synthesis; osmosis; operation of stomata
e.
sulfur—component of DNA; activates some enzymes
 

 97. 
In the nutrition of a plant, which element is classified as a macronutrient?
a.
zinc
b.
chlorine
c.
calcium
d.
molybdenum
e.
manganese
 
 
For the following questions, match the element to its major function in plants. Choices may be used more than once.

Function
A.component of lignin-biosynthetic enzymes
B.component of DNA and RNA
C.active in chlorophyll formation
D.active in amino acid formation
E.formation and stability of cell walls
 

 98. 
nitrogen
a.
A
b.
B
c.
C
d.
D
e.
E
 

 99. 
copper
a.
A
b.
B
c.
C
d.
D
e.
E
 

 100. 
Reddish-purple coloring of leaves, especially along the margins of young leaves, is a typical symptom of deficiency of which element?
a.
C
b.
M++
c.
N
d.
P
e.
K+
 

 101. 
Which of the following best describes the general role of micronutrients in plants?
a.
They are cofactors in enzymatic reactions.
b.
They are necessary for essential regulatory functions.
c.
They prevent chlorosis.
d.
They are components of nucleic acids.
e.
They are necessary for the formation of cell walls.
 

 102. 
Which of the following is not true of micronutrients in plants?
a.
They are the elements required in relatively small amounts.
b.
They are required for a plant to grow from a seed and complete its life cycle.
c.
They generally help in catalytic functions in the plant.
d.
They are the essential elements of small size and molecular weight.
e.
Overdoses of them can be toxic.
 

 103. 
If an African violet has chlorosis, which of the following elements might be a useful addition to the soil?
a.
chlorine
b.
molybdenum
c.
copper
d.
iodine
e.
magnesium
 

 104. 
Iron deficiency is often indicated by chlorosis in newly formed leaves. This suggests that
a.
iron is an immobile nutrient in plants.
b.
iron is tied up in formed chlorophyll molecules.
c.
the concentration of iron in the xylem sap decreases the further it is transported from the source in the soil.
d.
A and B only
e.
A, B, and C
 

 105. 
There are several properties of a soil in which typical plants would grow well. Of the following, which would be the least conducive to plant growth?
a.
abundant humus
b.
numerous soil organisms
c.
high clay content
d.
high porosity
e.
high cation exchange capacity
 

 106. 
A soil well suited for the growth of most plants would have all of the following properties except
a.
abundant humus.
b.
air spaces.
c.
good drainage.
d.
high cation exchange capacity.
e.
a high pH.
 

 107. 
What soil(s) is(are) the most fertile?
a.
humus only
b.
loam only
c.
silt only
d.
clay only
e.
both humus and loam
 
 
The figure below shows the results of a study to determine the effect of soil air spaces on plant growth. Use these data to answer the following questions.

nar005-1.jpg
 

 108. 
The best conclusion from the data in the figure above is that the plant
a.
grows best without air in the soil.
b.
grows fastest in 5 to 10% air.
c.
grows best in air levels above 15%.
d.
does not respond differently to different levels of air in the soil.
e.
would grow to 24 grams in 40% soil air.
 

 109. 
Why does overwatering a plant kill it?
a.
Water does not have all the necessary minerals a plant needs to grow.
b.
Water neutralizes the pH of the soil.
c.
The roots cannot get air.
d.
Water will attract parasites.
e.
Water will form hydrogen bonds with the root of the cell wall.
 

 110. 
All of the following contributed to the dust bowl in the American southwest during the 1930s except
a.
overgrazing by cattle.
b.
cutting of mature trees.
c.
plowing of native grasses.
d.
planting of field crops.
e.
lack of soil moisture.
 

 111. 
The N-P-K percentages on a package of fertilizer refer to the
a.
total protein content of the three major ingredients of the fertilizer.
b.
percentages of manure collected from different types of animals.
c.
relative percentages of organic and inorganic nutrients in the fertilizer.
d.
percentages of three important mineral nutrients.
e.
proportions of three different nitrogen sources.
 
 
Use the data below to answer the following questions.

In west Texas, cotton has become an important crop in the last several decades. However, in this hot, dry part of the country there is little rainfall, so farmers irrigate their cotton fields. They must also regularly fertilize the cotton fields because the soil is very sandy. The figure below shows the record of annual productivity (measured in kilograms of cotton per hectare of land) since 1960 in a west Texas cotton field.

nar006-1.jpg
 

 112. 
If you were the county agriculture agent, what would be the best advice you could give the farmer who owns the field under study in the figure above?
a.
Plant a variety of cotton that requires less water and can tolerate salinity.
b.
Continue to fertilize, but stop irrigating and rely on rainfall.
c.
Continue to irrigate, but stop fertilizing and rely on organic nutrients in the soil.
d.
Continue to fertilize and irrigate, but add the nitrogen-fixing bacteria Rhizobium to the irrigation water until the productivity increases.
e.
Add acid to the soil and increase its cation exchange capabilities so more nutrients are retained in the soil.
 

 113. 
A young farmer purchases some land in a relatively arid area and is interested in earning a reasonable profit for many years. Which of the following strategies would best allow such a goal to be achieved?
a.
establishing an extensive irrigation system
b.
using plenty of the best fertilizers
c.
finding a way to sell all parts of crop plants
d.
selecting crops adapted to arid areas
e.
converting hillsides into fields
 

 114. 
A farming commitment that embraces a variety of methods that are conservation-minded, environmentally safe, and profitable is called
a.
hydroponics.
b.
nitrogen fixation.
c.
responsible irrigation.
d.
genetic engineering.
e.
sustainable agriculture.
 

 115. 
An early use of indicator plants (plants that tolerate high levels of heavy metals in the soil) was to locate potential profitable areas to mine for those minerals. A current use for such plants is
a.
to help locate suitable sites for toxic waste storage.
b.
bioremediation to help clean up mine spoils.
c.
to minimize soil erosion in arid lands.
d.
nitrogen fixation by symbiotic bacteria in root nodules.
e.
all of the above
 

 116. 
Why is nitrogen fixation such an important process?
a.
Nitrogen fixation can only be done by certain prokaryotes.
b.
Fixed nitrogen is most often the limiting factor in plant growth.
c.
Nitrogen fixation is very expensive in terms of metabolic energy.
d.
Nitrogen fixers are sometimes symbiotic with legumes.
e.
Nitrogen-fixing capacity can be genetically engineered.
 

 117. 
Most crop plants acquire their nitrogen mainly in the form of
a.
NH3.
b.
N2.
c.
CN2H2.
d.
NO3-.
e.
amino acids absorbed from the soil.
 

 118. 
In a root nodule, the gene coding for nitrogenase
a.
is inactivated by leghemoglobin.
b.
is absent in active bacteroids.
c.
is found in the cells of the pericycle.
d.
protects the nodule from nitrogen.
e.
is part of the Rhizobium chromosome.
 

 119. 
If a legume is infected with Rhizobium, what is the probable effect on the plant?
a.
It gets chlorosis.
b.
It dies.
c.
It desiccates.
d.
It obtains nitrogen from nitrogen fixation.
e.
It contributes water to the soil.
 

 120. 
You are weeding your garden when you accidentally expose some roots. You notice swellings (root nodules) on the roots. Most likely your plant
a.
suffers from a mineral deficiency.
b.
is infected with a parasite.
c.
is benefiting from a mutualistic bacterium.
d.
is developing offshoots from the root.
e.
contains developing insect pupa.
 

 121. 
Which of the following is a true statement about nitrogen fixation in root nodules?
a.
The plant contributes the nitrogenase enzyme.
b.
The process is relatively inexpensive in terms of ATP costs.
c.
Leghemoglobin helps maintain a low O2 concentration within the nodule.
d.
The process tends to deplete nitrogen compounds in the soil.
e.
The bacteria of the nodule are autotrophic.
 

 122. 
The function of a root nodule's leghemoglobin is to
a.
extract macronutrients from the soil.
b.
regulate the supply of oxygen to Rhizobium.
c.
promote ion exchange in the soil.
d.
form a mutualistic relationship with insects.
e.
supply the legume with fixed nitrogen.
 

 123. 
How do legume plant roots communicate with Rhizobium bacteria?
a.
Flavonoids from Rhizobium create "nods."
b.
Plants activate early nodulin genes.
c.
Rhizobium secretes infection threads.
d.
Flavonoids trigger gene-regulating proteins in bacterium.
e.
Both A and C are correct.
 

 124. 
A woodlot was sprayed with a fungicide. What would be the most serious effect of such spraying?
a.
a decrease in food for animals that eat mushrooms
b.
an increase in rates of wood decay
c.
a decrease in tree growth due to the death of mycorrhizae
d.
an increase in the number of decomposing bacteria
e.
both A and B
 

 125. 
What is the mutualistic association between roots and fungi called?
a.
nitrogen fixation
b.
Rhizobium infection
c.
mycorrhizae
d.
parasitism
e.
root hair enhancement
 

 126. 
Hyphae form a covering over roots. Altogether, these hyphae create a large surface area that helps to do which of the following?
a.
aid in absorbing minerals and ions
b.
maintain cell shape
c.
increase cellular respiration
d.
anchor a plant
e.
protect the roots from ultraviolet light
 

 127. 
Which of the following is a primary difference between ectomycorrhizae and endomycorrhizae?
a.
Endomycorrhizae have thicker, shorter hyphae than ectomycorrhizae.
b.
Endomycorrhizae, but not ectomycorrhizae, form a dense sheath over the surface of the root.
c.
Ectomycorrhizae do not penetrate root cells, whereas endomycorrhizae grow into invaginations of the root cell membranes.
d.
Ectomycorrhizae are found in woody plant species; about 85% of plant families form ectomycorrhizae.
e.
There are no significant differences between ectomycorrhizae and endomycorrhizae.
 

 128. 
The earliest vascular plants on land had underground stems (rhizomes) but no roots. Water and mineral nutrients were most likely obtained by
a.
absorption by hairs and trichomes.
b.
diffusion through stomata.
c.
absorption by symbiotic fungi.
d.
osmosis through root hairs.
e.
diffusion across the cuticle of the rhizome.
 

 129. 
Dwarf mistletoe grows on many pine trees in the Rockies. Although the mistletoe is green, it is probably not sufficiently active in photosynthesis to produce all the sugar it needs. The mistletoe also produces haustoria. Thus, dwarf mistletoe growing on pine trees is best classified as
a.
an epiphyte.
b.
a nitrogen-fixing legume.
c.
a carnivorous plant.
d.
a symbiotic plant.
e.
a parasite.
 

 130. 
What are epiphytes?
a.
aerial vines common in tropical regions
b.
haustoria used for anchoring to host plants and obtaining xylem sap
c.
plants that live in poor soil and digest insects to obtain nitrogen
d.
plants that grow on other plants but do not obtain nutrients from their hosts
e.
plants that have a symbiotic relationship with fungi
 

 131. 
Carnivorous plants have evolved mechanisms that trap and digest small animals. The products of this digestion are used to supplement the plant's supply of
a.
energy.
b.
carbohydrates.
c.
lipids and steroids.
d.
minerals.
e.
water.
 

 132. 
The products of meiosis in plants are always which of the following?
a.
spores
b.
eggs
c.
sperm
d.
seeds
e.
both B and C
 

 133. 
Which of the following is the correct sequence during alternation of generations in a flowering plant?
a.
sporophyte-meiosis-gametophyte-gametes-fertilization-diploid zygote
b.
sporophyte-mitosis-gametophyte-meiosis-sporophyte
c.
haploid gametophyte-gametes-meiosis-fertilization-diploid sporophyte
d.
sporophyte-spores-meiosis-gametophyte-gametes
e.
haploid sporophyte-spores-fertilization-diploid gametophyte
 

 134. 
Which of the following is true in plants?
a.
Meiosis occurs in gametophytes to produce gametes.
b.
Meiosis occurs in sporophytes to produce spores.
c.
The gametophyte is the dominant generation in flowering plants.
d.
Plants exist continually as either sporophytes or gametophytes.
e.
Male gametophytes and female gametophytes have the same structure.
 

 135. 
All of the following are features of angiosperms except
a.
a triploid endosperm.
b.
an ovary that becomes a fruit.
c.
animal pollination.
d.
a small (reduced) sporophyte.
e.
double fertilization.
 

 136. 
Based on studies of plant evolution, which flower part is not a modified leaf?
a.
stamen
b.
carpel
c.
petal
d.
sepal
e.
receptacle
 

 137. 
All of the following floral parts are directly involved in pollination or fertilization except the
a.
stigma.
b.
anther.
c.
sepal.
d.
carpel.
e.
style.
 

 138. 
A mutation in which of the following floral parts would have the greatest impact on pollination?
a.
sepal
b.
petal
c.
stamen
d.
carpel
e.
either C or D
 

 139. 
A mutation in which of the following floral parts would have the greatest potential impact on fertilization?
a.
sepal
b.
petal
c.
stamen
d.
carpel
e.
either C or D
 

 140. 
Which of the following is the correct order of floral organs from the outside to the inside of a complete flower?
a.
petals-sepals-stamens-carpels
b.
sepals-stamens-petals-carpels
c.
spores-gametes-zygote-embryo
d.
sepals-petals-stamens-carpels
e.
male gametophyte-female gametophyte-sepals-petals
 

 141. 
Meiosis occurs within all of the following flower parts except the
a.
ovule.
b.
style.
c.
megasporangium.
d.
anther.
e.
ovary.
 

 142. 
A perfect flower is fertile, but may be either complete or incomplete. Which of the following correctly describes a perfect flower?
a.
It has no sepals.
b.
It has fused carpels.
c.
It is on a dioecious plant.
d.
It has no endosperm.
e.
It has both stamens and carpels.
 

 143. 
Carpellate flowers
a.
are perfect.
b.
are complete.
c.
produce pollen.
d.
are found only on dioecious plants.
e.
develop into fruits.
 

 144. 
Which of the following types of plants is not able to self-pollinate?
a.
dioecious
b.
monoecious
c.
complete
d.
wind-pollinated
e.
insect-pollinated
 

 145. 
Where does meiosis occur in flowering plants?
a.
megasporocyte
b.
microsporocyte
c.
endosperm
d.
pollen tube
e.
megasporocyte and microsporocyte
 

 146. 
Which of the following is a correct sequence of processes that takes place when a flowering plant reproduces?
a.
meiosis-fertilization-ovulation-germination
b.
fertilization-meiosis-nuclear fusion-formation of embryo and endosperm
c.
meiosis-pollination-nuclear fusion-formation of embryo and endosperm
d.
growth of pollen tube-pollination-germination-fertilization
e.
meiosis-mitosis-nuclear fusion-pollen
 

 147. 
Which of these is incorrectly paired with its life-cycle generation?
a.