Campbell Biology in Focus, 2e (Urry)
Chapter 29 Resource Acquisition, Nutrition, and Transport in Vascular Plants
29.1 Multiple-Choice Questions
1) Which one of the following is an adaptation by plants to life on land?
A) lack of waxy cuticle
B) Calvin cycle of photosynthesis
C) xylem tracheids and vessels
D) Krebs cycle of respiration
2) Which of the following was an essential adaptive feature for the evolution of plants from
water to the land?
A) minimizing the evaporative loss of water
B) using light more effectively
C) acquiring CO2 from the air
D) acquiring water from the ground
3) Given that early land plants most likely share a common ancestor with green algae, the earliest
land plants were most likely
A) nonvascular plants that grew leafless photosynthetic shoots above the shallow fresh water in
which they lived.
B) species that did not exhibit alternation of generations.
C) vascular plants with well-defined root systems.
D) plants with well-developed leaves.
4) The architecture and distribution of the root system and production of proteins in plants are
directly relevant to the availability ________ in soil.
A) of carbon dioxide
B) and richness of nitrates
C) of fungal association
D) of water
5) The symplast is the continuum of cytosol connected by
A) extracellular spaces.
B) apoplastic route.
C) plasmodesmata.
D) symplastic route.
6) Which of the following determines the direction of water movement across the membrane?
A) cell health
B) a difference in water potential
C) size of the cell
D) shape of the cell
7) Plants do not have a circulatory system like that of some animals. If a water molecule did
“circulate” (that is, go from one point in a plant to another and back in the same day), it would
require the activity of
A) only the xylem.
B) only the phloem.
C) only the endodermis.
D) both the xylem and the phloem.
8) Plasmodesmata can change in number, and when dilated can provide a passageway for
A) macromolecules such as RNA and proteins.
B) ribosomes.
C) chloroplasts.
D) mitochondria.
9) Typically, on average, what percentage of a plant’s fresh biomass is water?
A) 70-75
B) 65-75
C) 80-90
D) 75-80
10) 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
11) The movement of water across biological membranes can best be predicted by
A) negative charges in the cell wall.
B) prevailing weather conditions.
C) aquaporins.
D) water potentials.
12) An open beaker of pure water has a water potential (Ψ) of
A) -0.23 MPa.
B) +0.23 MPa.
C) +0.07 MPa.
D) 0.0 (zero).
13) If ΨP = 0.3 MPa and ΨS = –0.45 MPa, the resulting Ψ is
A) +0.75 MPa.
B) -0.75 MPa.
C) -0.15 MPa.
D) +0.15 MPa.
14) The value for Ψ 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 (Ψ = -0.23 MPa), the 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.
15) 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.
16) Water flows into the source end of a sieve tube because
A) sucrose has diffused into the sieve tube, making it hypotonic.
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.
17) What is the role of proton pumps in root hair cells?
A) establish ATP gradients
B) maintain the H+ gradient
C) pressurize xylem transport
D) eliminate excess electrons
18) One would expect to find the highest density of aquaporins in which of the following?
A) the plasma membrane of guard cells
B) the pits of a tracheid
C) the plasma membrane of parenchyma cells in a ripe fruit
D) the plasma membrane of a mature mesophyll cell in a leaf
19) If isolated plant cells with a water potential averaging -0.5 MPa are placed into a solution
with a water potential of -0.3 MPa, which of the following would be the most likely outcome?
A) The pressure potential of the cells would increase.
B) Water would move out of the cells.
C) The cell walls would rupture, killing the cells.
D) Solutes would move out of the cells.
20) Guard cells do which of the following?
A) protect the endodermis
B) accumulate K+ in order to close the stomata
C) contain chloroplasts that import K+ directly into the cells
D) help balance the photosynthesis–transpiration compromise
21) Photosynthesis begins to decline when leaves wilt because
A) chloroplasts within wilted leaves are incapable of photosynthesis.
B) CO2 accumulates in the leaves and inhibits the enzymes needed for photosynthesis.
C) there is insufficient water for photolysis during the light reactions.
D) stomata close, restricting CO2 entry into the leaf.
22) The opening of stomata is thought to involve
A) an increase in the solute concentration of the guard cells.
B) a decrease in the solute concentration of the stoma.
C) active transport of water out of the guard cells.
D) decreased turgor pressure in the guard cells.
23) The following factors may sometimes play a role in the movement of sap through xylem.
Which one depends on the direct expenditure of ATP by the plant?
A) capillarity of water within the xylem
B) evaporation of water from leaves
C) cohesion among water molecules
D) concentration of ions in the symplast
24) In which plant cell or tissue would the pressure component of water potential most often be
negative?
A) leaf mesophyll cell
B) stem xylem
C) stem phloem
D) root cortex cell
25) Water potential is generally most negative in which of the following parts of a plant?
A) mesophyll cells of the leaf
B) xylem vessels in leaves
C) xylem vessels in roots
D) cells of the root cortex
26) Which of the following has the lowest (most negative) water potential?
A) root cortical cells
B) root xylem
C) trunk xylem
D) leaf air spaces
27) Active transport would be least important in the normal functioning of which of the
following plant tissue types?
A) leaf transfer cells
B) stem tracheid element
C) root endodermal cells
D) leaf mesophyll cells
28) Which of the following essential nutrients plays an essential role in the opening and closing
of the stomatal aperture?
A) Fe
B) Bo
C) Mg
D) K
29) What is the driving force for the movement of solutes in the phloem of plants?
A) gravity
B) a difference in water potential (Ψ) between the source and the sink
C) root pressure
D) transpiration of water through the stomata
30) 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.
31) 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
32) Arrange the following five events in an order that explains the mass flow of materials in the
phloem.
1. Water diffuses into the sieve tubes.
2. Leaf cells produce sugar by photosynthesis.
3. Solutes are actively transported into sieve tubes.
4. Sugar is transported from cell to cell in the leaf.
5. Sugar moves down the stem.
A) 2, 1, 4, 3, 5
B) 1, 2, 3, 4, 5
C) 2, 4, 3, 1, 5
D) 4, 2, 1, 3, 5
33) For this pair of items, choose the option that best describes their relationship.
(a) The average size of particles that constitute silt
(b) The average size of particles that constitute clay
A) Item (a) is larger than item (b).
B) Item (a) is smaller than item (b).
C) Item (a) is exactly or very approximately equal to item (b).
D) Item (a) bears no relationship to item (b).
34) For this pair of items, choose the option that best describes their relationship.
(a) The amount of molybdenum in a gram of dried plant material
(b) The amount of sulfur in a gram of dried plant material
A) Item (a) is greater than item (b).
B) Item (a) is less than item (b).
C) Item (a) is exactly or very approximately equal to item (b).
D) There is not enough information to make a meaningful comparison.
35) Which of the following would be in the lowest concentration in an actively growing shoot
tip?
A) zinc
B) nitrogen
C) phosphorus
D) potassium
36) Atmospheric nitrogen can be fixed by nitrogen-fixing bacteria. Arrange the following forms
of nitrogen from the atmospheric N stage to the final form that enters the roots.
1. Ammonia
2. Nitrogen gas
3. Ammonium ion
4. Nitrite
5. Nitrate
A) 1, 2, 3, 4, 5
B) 2, 1, 3, 5, 4
C) 2, 1, 5, 4, 3
D) 2, 1, 3, 4, 5
37) If you wanted to increase the cation exchange and water retention capacity of loamy soil,
what should you do?
A) Adjust the soil pH to 7.9.
B) Add clay to the soil.
C) Practice no-till agriculture.
D) Add fertilizer containing potassium, calcium, and magnesium to the soil.
38) Several properties are characteristic 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) compacted soil
D) high porosity
39) 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 are deprived of oxygen.
D) Water supports the growth of root parasites.
40) Which of the following soil minerals is most likely leached away during a hard rain?
A) Na+
B) K+
C) Ca2+
D) NO3–
41) The NPK 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.
42) Most of the dry weight of a plant is derived from
A) NO3– and CO2.
B) K+ and CO2.
C) PO43- and K+.
D) H2O and CO2.
43) 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 the root cells
C) to inhibit the growth of aerobic algae
D) to inhibit the growth of anaerobic bacteria
44) 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
45) 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.
46) Which of the following elements is required for the stability of cell walls?
A) zinc
B) chlorine
C) calcium
D) molybdenum
47) Synthesis of which of the following compounds in a mature leaf would be least impacted by
a temporary soil nitrogen deficiency?
A) chlorophyll
B) DNA
C) RNA
D) cellulose
48) What is a major function of magnesium in plants?
A) to be a component of lignin-biosynthetic enzymes
B) to be a component of DNA and RNA
C) to be a component of chlorophyll
D) to be active in amino acid formation
49) Copper plays a critical role in ________ of plant cells.
A) water splitting in photosynthesis
B) redox reactions and lignin-biosynthetic enzymes
C) cytochromes
D) cofactor for enzymes needed for nitrogen fixation
50) Reddish-purple coloring of leaves, especially along the margins of young leaves, is a typical
symptom of deficiency of which element?
A) C
B) Mg2+
C) N
D) P
51) A corn (Zea mays) mutant is developed that is impaired in magnesium uptake. The most
likely phenotypic expression would be
A) chlorosis, especially in the older leaves.
B) a purple tinge to actively growing shoots.
C) severely stunted root growth and branching.
D) a reduction in leaf surface area.
52) If an African violet has chlorosis, which of the following elements might be a useful addition
to the soil?
A) chlorine
B) molybdenum
C) iodine
D) magnesium
53) Iron deficiency is often indicated by yellowing in newly formed leaves. This suggests that
iron
A) is a relatively immobile nutrient in plants.
B) is tied up in formed chlorophyll molecules.
C) is concentrated in the xylem of older leaves.
D) is concentrated in the phloem of older leaves.
54) Which of the following, if used as a fertilizer, would be most immediately available for plant
uptake?
A) NH3
B) N2
C) CN2H2
D) NO3–
55) The enzyme complex nitrogenase catalyzes the reaction that reduces atmospheric nitrogen to
A) N2.
B) NH3.
C) NO2–.
D) NO+.
56) 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) is part of the Rhizobium genome.
57) The most efficient way to increase essential amino acids in crop plants for human
consumption would be to
A) breed for higher yield of deficient amino acids.
B) increase the amount of fertilizer used on fields.
C) use 20-20-20 fertilizer instead of 20-5-5 fertilizer.
D) engineer nitrogen-fixing nodules into crop plants lacking them.