ch 37 practice problems
72) Mycorrhizae enhance plant nutrition mainly by A) absorbing water and minerals through the fungal hyphae. B) providing sugar to the root cells, which have no chloroplasts of their own. C) converting atmospheric nitrogen to ammonia. D) enabling the roots to parasitize neighboring plants. E) stimulating the development of root hairs.
A
23) 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
A Topic: Concept 37.1 Skill: Comprehension
17) copper 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
A Topic: Concept 37.1 Skill: Knowledge
19) 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.
A Topic: Concept 37.1 Skill: Knowledge
35) 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 Figure 37.2? 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.
A Topic: Concept 37.2 Skill: Application
30) What should be added to soil to prevent minerals from leaching away? A) humus B) sand C) mycorrhizae D) nitrogen E) silt
A Topic: Concept 37.2 Skill: Knowledge
45) The most efficient way to increase essential amino acids in crop plants for human consumption is 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. E) increase irrigation of nitrogen-fixing crops.
A Topic: Concept 37.3 Skill: Knowledge
54) 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
A Topic: Concept 37.4 Skill: Application
64) Which one of these is a nitrite? A) NO2- B) NH4- C) NH2 D) PO4- E) NO3-
A Topic: Web/CD Activity: The Nitrogen Cycle
65) Most of the mass of organic material of a plant comes from A) water. B) carbon dioxide. C) soil minerals. D) atmospheric oxygen. E) nitrogen.
B
66) Micronutrients are needed in very small amounts because A) most of them are mobile in the plant. B) most function as cofactors of enzymes. C) most micronutrients are supplied in large enough quantities in seeds. D) they play only a minor role in the growth and health of the plant. E) only the growing regions of the plants require micronutrients.
B
68) Based on our retrospective view, the most reasonable conclusion to draw from van Helmont's famous experiment on the growth of a willow is that A) the tree increased in mass mainly by photosynthesis. B) the increase in the mass of the tree could not be accounted for by the consumption of soil. C) most of the increase in the mass of the tree was due to the uptake of O2. D) soil simply provides physical support for the tree without providing nutrients. E) trees do not require water to grow.
B
69) A mineral deficiency is likely to affect older leaves more than younger leaves if A) the mineral is a micronutrient. B) the mineral is very mobile within the plant. C) the mineral is required for chlorophyll synthesis. D) the mineral is a macronutrient. E) the older leaves are in direct sunlight.
B
74) Carnivorous adaptations of plants mainly compensate for soil that has a relatively low content of A) potassium. B) nitrogen. C) calcium. D) water. E) phosphate.
B
5) 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
B Topic: Concept 37.1 Skill: Application
10) 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.
B Topic: Concept 37.1 Skill: Comprehension
16) nitrogen 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
B Topic: Concept 37.1 Skill: Knowledge
27) The best conclusion from the data in Figure 37.1 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.
B Topic: Concept 37.2 Skill: Application
32) 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.
B Topic: Concept 37.2 Skill: Knowledge
38) 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
B Topic: Concept 37.2 Skill: Knowledge
40) 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.
B Topic: Concept 37.3 Skill: Comprehension
43) The enzyme complex nitrogenase catalyzes the reaction that reduces atmospheric nitrogen to A) N2. B) NH3. C) NO2. D) NO⁺. E) NH⁻.
B Topic: Concept 37.3 Skill: Comprehension
41) In what way do nitrogen compounds differ from other minerals needed by plants? A) Only nitrogen can be lost from the soil. B) Only nitrogen requires the action of bacteria to be made available to plants. C) Only nitrogen is needed for protein synthesis. D) Only nitrogen is held by cation exchange capacity in the soil. E) Only nitrogen can be absorbed by root hairs.
B Topic: Concept 37.3 Skill: Knowledge
50) 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.
B Topic: Concept 37.4 Skill: Comprehension
46) Among important crop plants, nitrogen-fixing root nodules are most commonly an attribute of A) corn. B) legumes. C) wheat. D) members of the potato family. E) cabbage and other members of the brassica family.
B Topic: Concept 37.4 Skill: Knowledge
60) What process is the source of the CO2 that root hairs release into the soil? A) photosynthesis B) cellular respiration C) photolysis D) nitrogen fixation E) mycorrhizae
B Topic: Web/CD Activity: How Plants Obtain Minerals from Soil
61) Roots expend ATP to pump ________ ions from the root to the soil and by doing so displace mineral ions bound to soil particles. A) CO32- B) H+ C) He D) Mg2+ E) Ca2+
B Topic: Web/CD Activity: How Plants Obtain Minerals from Soil
67) It is valid to consider water a plant nutrient because A) plants die without a water source. B) cell elongation depends mainly on the osmotic absorption of water by cells. C) hydrogen and oxygen atoms from water molecules are incorporated into organic molecules. D) transpiration depends on a continuous supply of water to leaves. E) most of a plant's mass of organic compounds is derived from water.
C
70) Two groups of tomatoes were grown under laboratory conditions, one with humus added to the soil and one a control without the humus. The leaves of the plants grown without humus were yellowish (less green) compared with those of the plants grown in humus-enriched soil. The best explanation for this difference is that A) the healthy plants used the food in the decomposing leaves of the humus for energy to make chlorophyll. B) the humus made the soil more loosely packed, so water penetrated more easily to the roots. C) the humus contained minerals such as magnesium and iron, needed for the synthesis of chlorophyll. D) the heat released by the decomposing leaves of the humus caused more rapid growth and chlorophyll synthesis. E) the healthy plants absorbed chlorophyll from the humus.
C
11) 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
C Topic: Concept 37.1 Skill: Application
4) 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
C Topic: Concept 37.1 Skill: Application
6) 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.
C Topic: Concept 37.1 Skill: Application
12) 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
C Topic: Concept 37.1 Skill: Comprehension
2) 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
C Topic: Concept 37.1 Skill: Comprehension
1) Which of the following describes the fate of most of the water taken up by a plant? A) It is used as a solvent. B) It is used as a hydrogen source in photosynthesis. C) It is lost during transpiration. D) It makes cell elongation possible. E) It is used to keep cells turgid.
C Topic: Concept 37.1 Skill: Knowledge
14) In the nutrition of a plant, which element is classified as a macronutrient? A) zinc B) chlorine C) calcium D) molybdenum E) manganese
C Topic: Concept 37.1 Skill: Knowledge
15) zinc 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
C Topic: Concept 37.1 Skill: Knowledge
21) What is meant by the term chlorosis? A) the uptake of the micronutrient chlorine by a plant B) the formation of chlorophyll within the thylakoid membranes of a plant C) the yellowing of leaves due to decreased chlorophyll production D) a contamination of glassware in hydroponic culture E) release of negatively charged minerals such as chloride from clay particles in soil
C Topic: Concept 37.1 Skill: Knowledge
29) 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.
C Topic: Concept 37.2 Skill: Comprehension
24) 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
C Topic: Concept 37.2 Skill: Knowledge
52) 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
C Topic: Concept 37.4 Skill: Application
56) 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.
C Topic: Concept 37.4 Skill: Comprehension
48) 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.
C Topic: Concept 37.4 Skill: Comprehension
49) 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.
C Topic: Concept 37.4 Skill: Comprehension
53) What is the mutualistic association between roots and fungi called? A) nitrogen fixation B) Rhizobium infection C) mycorrhizae D) parasitism E) root hair enhancement
C Topic: Concept 37.4 Skill: Knowledge
55) 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.
C Topic: Concept 37.4 Skill: Knowledge
71) The specific relationship between a legume and its symbiotic Rhizobium strain probably depends on A) each legume having a specific set of early nodulin genes. B) each Rhizobium strain having a form of nitrogenase that works only in the appropriate legume host. C) each legume being found where the soil has only the Rhizobium specific to that legume. D) specific recognition between the chemical signals and signal receptors of the Rhizobium strain and legume species. E) destruction of all incompatible Rhizobium strains by enzymes secreted from the legume's roots.
D
73) We would expect the greatest difference in size and general appearance between two groups of plants of the same species, one group with mycorrhizae and one without, in an environment A) where nitrogen-fixing bacteria are abundant. B) that has soil with poor drainage. C) that has hot summers and cold winters. D) in which the soil is relatively deficient in mineral nutrients. E) that is near a body of water, such as a pond or river.
D
20) 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.
D Topic: Concept 37.1 Skill: Application
8) 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
D Topic: Concept 37.1 Skill: Application
9) 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
D Topic: Concept 37.1 Skill: Comprehension
18) 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+
D Topic: Concept 37.1 Skill: Knowledge
36) 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
D Topic: Concept 37.2 Skill: Application
34) Based on the information provided above, what is the most likely cause of the decline in productivity? A) The farmer used the wrong kind of fertilizer. B) The cotton is developing a resistance to the fertilizer and to irrigation water. C) Water has accumulated in the soil due to irrigation. D) The soil has become hyperosmotic to the roots due to salination. E) The rate of photosynthesis has declined due to irrigation.
D Topic: Concept 37.2 Skill: Application
31) Which soil mineral is most likely leached away during a hard rain? A) Na+ B) K+ C) Ca++ D) NO3- E) H+
D Topic: Concept 37.2 Skill: Comprehension
33) 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.
D Topic: Concept 37.2 Skill: Knowledge
39) Nitrogen fixation is a process that A) recycles nitrogen compounds from dead and decaying materials. B) converts ammonia to nitrate. C) releases nitrate from the rock substrate. D) converts nitrogen gas into ammonia. E) both A and B
D Topic: Concept 37.3 Skill: Comprehension
42) 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.
D Topic: Concept 37.3 Skill: Comprehension
47) 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.
D Topic: Concept 37.4 Skill: Comprehension
51) 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.
D Topic: Concept 37.4 Skill: Knowledge
58) 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
D Topic: Concept 37.4 Skill: Knowledge
59) 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.
D Topic: Concept 37.4 Skill: Knowledge
13) 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
E Topic: Concept 37.1 Skill: Application
22) 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
E Topic: Concept 37.1 Skill: Application
7) Which of the following essential nutrients does not have a role in photosynthesis, either as a structural component or in the synthesis of a component? A) Fe B) Bo C) Mg D) H E) K
E Topic: Concept 37.1 Skill: Comprehension
3) Organic molecules make up what percentage of the dry weight of a plant? A) 6% B) 17% C) 67% D) 81% E) 96%
E Topic: Concept 37.1 Skill: Knowledge
28) The best explanation for the shape of this growth response curve is that A) the plant requires air in the soil for photosynthesis. B) the roots are able to absorb more nitrogen (N2) in high levels of air. C) most of the decrease in weight at low air levels is due to transpiration from the leaves. D) increased soil air produces more root mass in the soil but does not affect the top stems and leaves. E) the roots require oxygen for respiration and growth.
E Topic: Concept 37.2 Skill: Comprehension
26) 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
E Topic: Concept 37.2 Skill: Knowledge
25) 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.
E Topic: Concept 37.2 Skill: Knowledge
37) 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.
E Topic: Concept 37.2 Skill: Knowledge
44) 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.
E Topic: Concept 37.3 Skill: Knowledge
57) 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.
E Topic: Concept 37.4 Skill: Application
62) Acid precipitation A) promotes the attachment of anions to soil particles. B) enhances the diffusion of cations into root hairs. C) has no effect on soil fertility. D) increases soil fertility. E) decreases soil fertility.
E Topic: Web/CD Activity: How Plants Obtain Minerals from Soil
63) Denitrifying bacteria convert ________ to ________. A) ammonium; nitrogen gas B) nitrates; nitrogen gas C) nitrogen gas; ammonium D) nitrogen gas; nitrates E) nitrogen gas; nitrites
E Topic: Web/CD Activity: The Nitrogen Cycle
