This Document Contains Chapters 29 to 30 Chapter 29: Resource Acquisition, Nutrition, and Transport in Vascular Plants 29.1 Multiple-Choice Questions 1) All of the following are plant adaptations to life on land except A) tracheids and vessels. B) root hairs. C) cuticle. D) the Calvin cycle of photosynthesis. E) collenchyma. Answer: D 2) The ancestors of land plants were aquatic algae. Which of the following is not an evolutionary adaptation to life on land? A) C3 photosynthesis B) a waxy cuticle C) root hairs D) xylem and phloem E) guard cells Answer: A 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. E) species with a well-developed, thick cuticle. Answer: A 4) All of the following normally enter the plant through the roots except A) carbon dioxide. B) nitrogen. C) potassium. D) water. E) calcium. Answer: A 5) Which of the following statements about xylem is incorrect? A) It conducts material from root tips to leaves. B) The conducting cells are part of the apoplast. C) It transports mainly sugars and amino acids. D) It typically has a lower water potential than is found in soil. E) No energy input is required for transport. Answer: C 6) 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. Answer: E 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 endodermis. E) both the xylem and the phloem. Answer: E 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. E) cytoskeletal components. Answer: A 9) Which structure or compartment is not part of the plant's apoplast? A) the lumen of a xylem vessel B) the lumen of a sieve tube C) the cell wall of a mesophyll cell D) the cell wall of a transfer cell E) the cell wall of a root hair Answer: B 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 E) a difference in water potential Answer: C 11) Active transport involves all of the following except A) diffusion of solute through the lipid bilayer of a membrane. B) pumping of solutes across the membrane. C) hydrolysis of ATP. D) transport of solute against a concentration gradient. E) specific transport proteins in the membrane. Answer: A 12) Active transport of various materials in plants at the cellular level requires all of the following except A) a proton gradient. B) ATP. C) a membrane potential. D) transport proteins E) xylem membranes. Answer: E 13) 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 Answer: D 14) 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) level of active transport. E) water potentials. Answer: E 15) 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) -0.0000001 MPa. E) 0.0 (zero). Answer: E 16) All of the following have an effect on water potential (Ψ) in plants except A) physical pressure. B) water-attracting matrices. C) dissolved solutes. D) osmosis. E) DNA structure. Answer: E 17) 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. E) -0.42 MPa. Answer: C 18) 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. E) be impossible to determine from the values given here. Answer: A 19) 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. Answer: A 20) Which of the following statements is false about bulk flow? A) It is driven primarily by pressure potential. B) It is more effective than diffusion over distances greater than 100 μm. C) It depends on a difference in pressure potential at the source and sink. D) It depends on the force of gravity on a column of water. E) It may be the result of either positive or negative pressure potential. Answer: D 21) 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. E) sucrose has been transported out of the sieve tube by active transport. Answer: B 22) Which of the following does not involve active transport across membranes? A) the movement of mineral nutrients from the apoplast to the symplast B) the movement of mineral nutrients from mesophyll cells into xylem cells C) the movement of sugar from one sieve-tube element to the next D) the movement of K+ across guard cell membranes during stomatal opening E) the movement of mineral nutrients into cells of the root cortex Answer: C 23) 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 E) assist in active uptake of water molecules Answer: B 24) Which of the following is not an important component of the long-distance transport process in plants? A) the cohesion of water molecules B) a negative water potential C) the root parenchyma D) the active transport of solutes E) bulk flow from source to sink Answer: C 25) 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 E) the membrane lining plasmodesmata Answer: A 26) 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. E) The osmotic pressure of the cells would decrease. Answer: A 27) 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 lignin and 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; solutes in xylem sap move due to a positive 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. Answer: D 28) 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) guard against mineral loss through the stomata E) help balance the photosynthesis—transpiration compromise Answer: E 29) 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. E) extreme heat causes photosynthetic enzymes to denature. Answer: D 30) 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. E) movement of K+ from the guard cells. Answer: A 31) 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 E) bulk flow of water in the root apoplast Answer: D 32) 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 E) root epidermis Answer: B 33) 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 E) root hairs Answer: A 34) Which of the following has the lowest (most negative) water potential? A) root cortical cells B) root xylem C) trunk xylem D) leaf cell walls E) leaf air spaces Answer: E 35) Active transport would be least important in the normal functioning of which of the following plant tissue types? A) leaf transfer cells B) stem tracheary elements C) root endodermal cells D) leaf mesophyll cells E) root sieve-tube elements Answer: B 36) 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) H E) K Answer: E 37) 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 E) adhesion of water to phloem sieve tubes Answer: B 38) Phloem transport of sucrose is often 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 Answer: D 39) 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. Answer: B 40) 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 Answer: B 41) 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 E) 2, 4, 1, 3, 5 Answer: C 42) 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). Answer: A 43) For this pair of items, choose the option that best describes their relationship. (a) The amount of nitrogen in a fertilizer marked "15-10-5" (b) The amount of nitrogen in a fertilizer marked "15-5-5" 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) Item (a) is unrelated to item (b). Answer: C 44) 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. Answer: B 45) Which of the following would be in the lowest concentration in an actively growing shoot tip? A) zinc B) nitrogen C) phosphorus D) potassium E) calcium Answer: A 46) 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. E) Increase the number of sand particles in the soil. Answer: B 47) 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 E) high cation exchange capacity Answer: C 48) 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. Answer: E 49) 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. E) Water lowers the water potential of the roots. Answer: C 50) Which of the following soil minerals is most likely leached away during a hard rain? A) Na+ B) K+ C) Ca2+ D) NO3- E) H+ Answer: D 51) 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. E) proportions of three different nitrogen sources. Answer: D 52) 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 K+. E) H2O and CO2. Answer: E 53) 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 E) to provide CO2 for photosynthesis Answer: B 54) 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 Answer: D 55) 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. Answer: B 56) 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 Answer: E 57) Which of the following elements is required for the stability of cell walls? A) zinc B) chlorine C) calcium D) molybdenum E) manganese Answer: C 58) 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) amino acids E) cellulose Answer: E 59) 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 E) to be required to regenerate phosphoenolpyruvate in C4 and CAM plants Answer: C 60) 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 E) K+ Answer: D 61) Which of the following is not true of micronutrients in plants? A) They are 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) Deficiencies vary widely by soil type. Answer: D 62) 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. E) a delay in flowering. Answer: A 63) 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 Answer: E 64) 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. E) is found in leghemoglobin and reduces the amount available to new plant parts. Answer: A 65) 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 E) amino acids Answer: D 66) The enzyme complex nitrogenase catalyzes the reaction that reduces atmospheric nitrogen to A) N2 B) NH3 C) NO2 D) NO+ E) NO- Answer: B 67) 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 genome. Answer: E 68) 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. E) increase irrigation of nitrogen-fixing crops. Answer: A 69) If a plant is infected with nitrogen-fixing bacteria, what is the most probable effect on the plant? A) It gets chlorosis. B) It dies. C) It will have a higher concentration of N2 in its roots and shoots. D) It will likely grow faster than an uninfected plant. E) It becomes flaccid due to the loss of water and nutrients from the roots. Answer: D 70) You are weeding your garden when you accidentally expose some roots of your pea plants. You notice swellings (root nodules) on the roots and there is a reddish tinge to the ones you accidentally damaged. Most likely your peas plants A) suffer from a mineral deficiency. B) are infected with a parasite. C) are benefiting from a mutualistic bacterium. D) are developing offshoots from the root. E) contain developing insect pupa. Answer: C 71) 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. Answer: C 72) Upregulation of leghemoglobin biosynthesis in a leguminous species would most likely indicate A) the plant is suffering from a mineral deficiency. B) the successful inoculation of nitrogen-fixing bacteria. C) the plant is suffering from water stress. D) the plant has been infected with mycorrhizae. E) an increase in the biosynthesis of amino acids. Answer: B 73) Which of the following is not a function of rhizobacteria? A) produce hormones that stimulate plant growth B) produce antibiotics that protect roots from disease C) absorb toxic metals D) carry out nitrogen fixation E) supply growing roots with glucose Answer: E 74) An example of a mutualistic association between a plant and a fungus would be A) nitrogen fixation. B) Rhizobium infection. C) mycorrhizae. D) parasitic infection. E) assisted pollination. Answer: C 75) Hyphae form a covering over roots. 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 Answer: A 76) 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. Answer: C 77) 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 mycorrhizae. D) osmosis through the root hairs. E) diffusion across the cuticle of the rhizome. Answer: C 78) A rootless, green plant is found growing on the branches and trunks of rain forest trees, but lacks any apparent adaptation for collecting rainwater. This plant is most likely A) an epiphyte. B) a nitrogen-fixing plant. C) a carnivorous plant. D) a symbiotic plant. E) a parasite. Answer: E 79) 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 Answer: D 80) 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. Answer: D 81) Rhizobia and mycorrhizae share all of the following features except A) they both benefit by receiving carbohydrate from the plant. B) many are host-specific. C) they both become parasitic in nutrient-rich environments. D) they both enhance the growth of most plants. E) they both are found in most ecosystems of the world. Answer: C 82) Rhizobia, actinomycetes, and cyanobacteria all share the common feature that they can A) increase water uptake in plants. B) increase nutrient availability in the soil for plants. C) kill parasites in the soil. D) exist in extreme environments. E) fix atmospheric nitrogen. Answer: E 83) Why is nitrogen fixation an essential process? A) Nitrogen fixation can only be done by certain prokaryotes. B) Fixed nitrogen is 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. Answer: B 84) 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. Answer: B 85) Nitrogen fixation is a process that A) recycles nitrogen compounds from dead and decaying materials. B) converts ammonia to ammonium. C) releases nitrate from the rock substrate. D) converts nitrogen gas into ammonia. E) recycles nitrogen compounds from dead and decaying materials, and converts ammonia to ammonium. Answer: D 86) Which of the following would be the most effective strategy to remove toxic heavy metals from a soil? A) heavy irrigation to leach out the heavy metals B) application of fertilizers to compete with heavy metal uptake C) application of sulfur to lower the soil pH and precipitate the heavy metals D) adding plant species that have the ability to take up and accumulate heavy metals E) inoculating soil with mycorrhizae to avoid heavy metal uptake Answer: D 87) Which of the following plant structures shares the most common features and functions with a fungal hyphae? A) stomata B) vascular cambium C) lenticels D) root hairs E) prop roots Answer: D 88) A plant developed a mineral deficiency after being treated with a fungicide. What is the most probable cause of the deficiency? A) Mineral receptor proteins in the plant membrane were not functioning. B) Mycorrhizal fungi were killed. C) Active transport of minerals was inhibited. D) The genes for the synthesis of transport proteins were destroyed. E) Proton pumps reversed the membrane potential. Answer: B 89) 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) B and D. Answer: E 90) 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 Answer: B 91) 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 best supports this view? A) cell wall B) cell membrane C) cytosol D) vacuole E) plasmodesmata Answer: E 92) 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. Answer: C 93) 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 Answer: D 94) In plant roots, the Casparian strip is correctly described by which of the following? A) It aids in the uptake of nutrients. 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 membrane before entering the stele. E) It provides increased surface area for the absorption of mineral nutrients. Answer: D 95) What drives the flow of water through the xylem? A) passive transport by the endodermis B) the number of companion cells in the phloem C) the evaporation of water from the leaves D) active transport by sieve-tube elements E) active transport by tracheid and vessel elements Answer: C 96) 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 Answer: C 97) 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. Answer: D 98) Water rises in plants primarily by cohesion-tension. Which of the following is not true about the cohesion-tension model? A) Water loss (transpiration) is the driving force for water movement. B) The "tension" of this model represents the excitability of the xylem cells. C) Cohesion represents the tendency for water molecules to stick together by hydrogen bonds. D) The physical forces in the capillary-sized xylem cells make it easier to overcome gravity. E) The water potential of the air is more negative than the xylem. Answer: B 99) Most of the water taken up by a plant is A) used as a solvent. B) used as a hydrogen source in photosynthesis. C) lost during transpiration. D) converted to CO2. E) used to keep cells turgid. Answer: C 100) Assume that a particular chemical interferes with the establishment and maintenance of proton gradients across the membranes of plant cells. All of the following processes would be directly affected by this chemical except A) photosynthesis. B) phloem loading. C) xylem transport. D) cellular respiration. E) stomatal opening. Answer: C 101) Which cells in a root form a protective barrier to the vascular system where all materials must move through the symplast? A) pericycle B) cortex C) epidermis D) endodermis E) exodermis Answer: D 102) The water lost during transpiration is a 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) increased growth. E) evaporative cooling and mineral transport. Answer: E 103) 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 Answer: B 104) 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 Answer: B 105) All of the following are adaptations that help reduce water loss from a plant except A) transpiration. B) sunken stomata. C) photosynthesis. D) small, thick leaves. E) crassulacean acid metabolism. Answer: A 106) 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 taproot Answer: E 107) 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 stoma. D) CO2 and O2 through stomata in leaves. E) carbohydrates in the root hairs and concentration in the root cortex. Answer: C 108) 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. Answer: B 109) According to the pressure flow hypothesis of phloem transport, A) solute moves from a high concentration in the source to a lower concentration in the sink. B) water is actively transported into the source region of the phloem to create the turgor pressure needed. C) the combination of a high turgor pressure in the source and transpiration water loss from the sink moves solutes through phloem conduits. D) the formation of starch from sugar in the sink increases the osmotic concentration. E) the pressure in the phloem of a root is normally greater than the pressure in the phloem of a leaf. Answer: A 110) If you were to prune the shoot tips of a plant, what would be the effect on the plant and the leaf area index? A) bushier plants; lower leaf area index B) tall plants; lower leaf area index C) tall plants; higher leaf area index D) short plants; lower leaf area index E) bushier plants; higher leaf area indexes Answer: E 111) 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. Answer: B 112) All of the following contributed to the dust bowl in the American southwest during the 1930s except A) overgrazing by cattle. B) clear-cutting of forest trees. C) plowing of native grasses. D) planting of field crops. E) lack of soil moisture. Answer: B 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 the farmer to achieve such a goal? 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 Answer: D 114) 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 Answer: D 29.2 Art 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. Figure 29.1 shows the record of annual productivity (measured in kilograms of cotton per hectare of land) since 1960 in a west Texas cotton field. Use these data to answer the following questions. Figure 29.1 1) Based on the information provided in Figure 29.1, 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 water potential has become more negative due to salination. E) The rate of photosynthesis has declined due to irrigation. Answer: D 2) 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 29.1? A) Plant a variety of cotton that requires less water and can tolerate salinity. B) Continue to fertilize, but stop irrigating the field and rely on rainfall. C) Continue to irrigate, but stop fertilizing the field 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. Answer: A 29.3 Scenario Questions 1) 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 organic molecules? A) 1 gram B) 4 grams C) 40 grams D) 960 grams E) 1 kg Answer: D 2) Ten tomato plants are germinated and maintained in a large tray with no drainage. After several weeks they all begin to wilt and die despite repeated watering and fertilization. The most likely cause of this die-off is A) competition for resources. B) anoxia. C) organic nutrient depletion. D) no room left for root growth. E) buildup of toxic substances in the tray. Answer: B 3) A greenhouse experiment to test growth rates in tomato cultivars was conducted using sterile soil mix and watering with sterile solutions of water and fertilizer. Following germination, half of the plants in each group were transplanted into soil that was obtained from a nearby agricultural field (nonsterile), and the other half into sterile soil. After several weeks the plants that were transplanted into nonsterile soil exhibited a much higher growth rate compared to the plants transplanted into sterile soil. The most likely explanation for this result is A) the plants transplanted into the nonsterile soil were inoculated with mycorrhizae. B) the plants transplanted into the nonsterile soil received more fertilizer. C) the plants transplanted into the sterile soil were stunted due to overfertilization. D) the plants transplanted into sterile soil suffered anoxia from improper water drainage. Answer: A 4) Several tomato plants are growing in a small garden plot. If soil water potential were to drop significantly on a hot summer afternoon, which of the following would most likely occur? A) Stomatal apertures would decrease. B) Transpiration would increase. C) The leaves would become more turgid. D) The uptake of CO2 would be enhanced. E) The proton gradient would dissipate. Answer: A 5) A fellow student brought in a leaf to be examined. The leaf was dark green, thin, had stoma on the lower surface only, and had a total surface area of 10 square meters. Where is the most likely environment where this leaf was growing? A) a dry, sandy region B) a large, still pond C) a tropical rain forest D) an oasis within a grassland E) the floor of a deciduous forest Answer: C 29.4 End-of-Chapter Questions 1) Which structure or compartment is part of the symplast? A) the interior of a vessel element B) the interior of a sieve tube C) the cell wall of a mesophyll cell D) an extracellular air space E) a Casparian strip Answer: B 2) Which of the following is an adaptation that enhances the uptake of water and minerals by roots? A) mycorrhizae B) cavitation C) active uptake by vessel elements D) rhythmic contractions by cortical cells E) pumping through plasmodesmata Answer: A 3) Which structure or compartment is part of the symplast? A) the interior of a vessel element B) the interior of a sieve tube C) the cell wall of a mesophyll cell D) an extracellular air space E) the cell wall of a root hair Answer: B 4) Movement of xylem sap from roots to leaves A) occurs through the apoplast of sieve-tube elements. B) usually depends on tension, or negative pressure potential. C) depends on active transport. D) depends on the pumping of water through aquaporins. E) results mainly from diffusion. Answer: B 5) What would enhance water uptake by a plant cell? A) decreasing the Ψ of the surrounding solution B) increasing the pressure exerted by the cell wall C) the loss of solutes from the cell D) increasing the Ψ of the cytoplasm E) positive pressure on the surrounding solution Answer: E 6) A plant cell with a ΨS of -0.65 MPa maintains a constant volume when bathed in a solution that has a ΨS of -0.30 MPa and is in an open container. The cell has a A) ΨP of +0.65 MPa. B) Ψ of -0.65 MPa. C) ΨP of +0.35 MPa. D) ΨP of +0.30 MPa. E) Ψ of 0 MPa. Answer: C 7) Compared with a cell with few aquaporin proteins in its membrane, a cell containing many aquaporin proteins 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) accumulate water by active transport. Answer: A 8) 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. Answer: B 9) Two groups of tomatoes were grown in the laboratory, one with humus added to the soil and the other a control without 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 carbohydrates 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. Answer: C Chapter 30: Reproduction and Domestication of Flowering Plants 30.1 Multiple-Choice Questions 1) A flowering plant with a deleterious mutation in microsporogenesis would most likely A) fail to produce sepals. B) fail to produce petals. C) fail to produce anthers. D) fail to produce pollen. E) fail to produce ovules. Answer: D 2) A mature, unfertilized ovule in an angiosperm is the result of A) a single meiotic division. B) a single mitotic division. C) both meiotic and mitotic divisions. D) mitosis from the megaspore mother cell. E) differentiation from the suspensor tissues. Answer: C 3) At the conclusion of meiosis in plants, the end products are always four haploid A) spores. B) eggs. C) sperm. D) seeds. E) gametes. Answer: A 4) Which of the following is the correct sequence during the alternation of generations life cycle 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 Answer: A 5) Which of the following statements is true of plants? A) Mitosis occurs in gametophytes to produce gametes. B) Meiosis occurs in sporophytes to produce spores. C) The gametophyte is within the flower in angiosperms. D) Mitosis occurs in gametophytes to produce gametes, and meiosis occurs in sporophytes to produce spores. E) Mitosis occurs in gametophytes to produce gametes, meiosis occurs in sporophytes to produce spores, and the gametophyte is within the flower in angiosperms. Answer: E 6) Which of the following statements is true of most angiosperms? A) They have a triploid endosperm within the seed. B) They have an ovary that becomes a fruit. C) They have a small (reduced) sporophyte. D) They have a triploid endosperm within the seed and an ovary that becomes a fruit. E) They have a triploid endosperm within the seed, an ovary that becomes a fruit, and a small (reduced) sporophyte. Answer: D 7) The ovary is most often located on/in the A) stamen. B) carpel. C) petals. D) sepals. E) receptacle. Answer: B 8) Microsporangia in flowering plants are located in the A) stamen. B) carpel. C) petals. D) sepals. E) receptacle. Answer: A 9) 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 Answer: D 10) In some angiosperms, other floral parts contribute to what is commonly called the fruit. Which of the following fruits is derived mostly from an enlarged receptacle? A) pea B) raspberry C) apple D) pineapple E) peach Answer: C 11) All of the following are primary functions of flowers except A) pollen production. B) photosynthesis. C) meiosis. D) egg production. E) sexual reproduction. Answer: B 12) Meiosis occurs within all of the following flower parts except the A) ovule. B) style. C) megasporangium. D) anther. E) ovary. Answer: B 13) Which of the following statements regarding flowering plants is false? A) The sporophyte is the dominant generation. B) Female gametophytes develop from megaspores within the anthers. C) Pollination is the delivery of pollen to the stigma of a carpel. D) The food-storing endosperm is derived from the cell that contains two polar nuclei and one sperm nucleus. E) Flowers produce fruits from the ovaries. Answer: B 14) In flowering plants, pollen is released from the A) anther. B) stigma. C) carpel. D) filament. E) pollen tube. Answer: A 15) In the life cycle of an angiosperm, which of the following stages is diploid? A) megaspore B) generative nucleus of a pollen grain C) polar nuclei of the embryo sac D) microsporocyte E) both megaspore and polar nuclei Answer: D 16) Where does meiosis occur in a flowering plant? A) megasporocyte B) microsporocyte C) endosperm D) pollen tube E) megasporocyte and microsporocyte Answer: E 17) 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 Answer: C 18) Which of the following is incorrectly paired with its life-cycle generation? A) anther–gametophyte B) pollen–gametophyte C) embryo sac–gametophyte D) stamen–sporophyte E) embryo–sporophyte Answer: A 19) Which of the following is the correct sequence of events in a pollen sac? A) sporangia → meiosis → two haploid cells → meiosis → two pollen grains per cell B) pollen grain → meiosis → two generative cells → two tube cells per pollen grain C) two haploid cells → meiosis → generative cell → tube cell-fertilization → pollen grain D) pollen grain → mitosis → microspores → meiosis → generative cell plus tube cell E) microsporocyte → meiosis → microspores → mitosis → two haploid cells per pollen grain Answer: E 20) Which of the following occurs in an angiosperm ovule? A) An antheridium forms from the megasporophyte. B) A megaspore mother cell undergoes meiosis. C) The nucleus forms a diploid egg. D) A pollen tube emerges to accept pollen after pollination. E) The endosperm surrounds the megaspore mother cell. Answer: B 21) Where and by which process are sperm cells formed in plants? A) meiosis in pollen grains B) meiosis in anthers C) mitosis in male gametophyte pollen tube D) mitosis in the micropyle E) mitosis in the embryo sac Answer: C 22) In which of the following pairs are the two terms equivalent? A) ovule–egg B) embryo sac–female gametophyte C) endosperm–male gametophyte D) seed–zygote E) microspore–pollen grain Answer: B 23) Which of the following would be considered a multiple fruit? A) apple B) strawberry C) raspberry D) pineapple E) corn on the cob Answer: D 24) In flowering plants, a mature male gametophyte contains A) two haploid gametes and a diploid pollen grain. B) a generative cell and a tube cell. C) two sperm nuclei and one tube cell nucleus. D) two haploid microspores. E) a haploid nucleus and a diploid pollen wall. Answer: C 25) Three mitotic divisions within the female gametophyte of a flowering plant will produce A) three antipodal cells, two polar nuclei, one egg, and two synergids. B) the triple fusion nucleus. C) three pollen grains. D) two antipodal cells, two polar nuclei, two eggs, and two synergids. E) a tube nucleus, a generative cell, and a sperm cell. Answer: A 26) What is the difference between pollination and fertilization in flowering plants? A) Fertilization precedes pollination. B) Pollination easily occurs between plants of different species, whereas fertilization is within a species. C) Pollen is formed within megasporangia so that male and female gametes are near each other. D) Pollination is the transfer of pollen from an anther to a stigma. Fertilization is the fusion of haploid nuclei. E) If fertilization occurs, pollination is unnecessary. Answer: D 27) As a flower develops, which transition is most likely to occur? A) The microspores become pollen grains. B) The ovule becomes a fruit. C) The petals are retained. D) The vegetative nucleus becomes a sperm nucleus. E) The ovules become ovaries. Answer: A 28) The primary function of the integument of an ovule is to A) protect against animal predation. B) ensure double fertilization. C) form a seed coat. D) direct development of the endosperm. E) produce hormones that ensure successful pollination. Answer: C 29) Which of the following events suggests there is a change in the egg cell membrane after penetration by a sperm? A) The pollen tube grows away from the egg toward the polar nuclei. B) The Ca2+ concentration increases in the cytoplasm of the egg. C) The egg plasmolyzes. D) Double fertilization occurs. E) The egg changes color. Answer: B 30) The structure of a mature, functional fruit always includes A) one or more seeds. B) extensive vascular connections to the parent plant. C) fleshy cells rich in sugars. D) brightly colored pigments to attract animal dispersers. E) subtending bracts to protect against predators. Answer: A 31) Which of the following statements argues an advantage for flowering plants to maintain an extended gametophyte generation? A) The protection of female gametophytes within ovules keeps them from drying out. B) Sperm with flagella can reach the egg faster. C) It provides sufficient time for the integument to develop into a seed coat. D) It allows for a complex nucleus to develop. E) It allows more time for potential pollination. Answer: A 32) What is typically the result of double fertilization in angiosperms? A) The endosperm develops into a diploid nutrient tissue. B) A triploid zygote is formed. C) Both a diploid embryo and triploid endosperm are formed. D) Two embryos develop in every seed. E) The antipodal cells develop into the seed coat. Answer: C 33) Which of the following "vegetables" is botanically a fruit? A) potato B) lettuce C) radish D) celery E) green beans Answer: E 34) The embryo of a grass seed is enclosed by two protective sheaths, a(n) ________, which covers the young shoot, and a(n) ________, which covers the young root. A) cotyledon; radicle B) hypocotyl; epicotyl C) coleoptile; coleorhiza D) scutellum; coleoptile E) epicotyl; radicle Answer: C 35) Fruits develop from A) microsporangia. B) receptacles. C) fertilized eggs. D) ovaries. E) ovules. Answer: D 36) What is the first step in the germination of a seed? A) pollination B) fertilization C) imbibition D) hydrolysis of starch and other food reserves E) emergence of the radicle Answer: C 37) Which of the following best describes the ploidy level of a fertilized embryo sac? A) All cells are diploid. B) All cells are triploid. C) All cells are polyploid. D) The ploidy level varies among species. E) There are haploid, diploid, and triploid cells. Answer: E 38) A parent with an S1S2 genotype exhibiting sporophytic self-incompatibility can potentially fertilize which of the following plant genotypes of the same species with pollen grains? A) S1S3 B) S2S3 C) S3S4 D) S1S4 E) Half of all the pollen grains could be successful. Answer: C 39) S1 pollen from an S1S2 genotype in a species exhibiting gametophytic self-incompatibility could potentially fertilize all the eggs in which genotype(s) of the same species? A) S1S1 B) S1S2 C) S1S3 D) S2S3 E) A, B and C Answer: D 40) Carpellate flowers A) are perfect. B) are complete. C) produce pollen. D) are found only on dioecious plants. E) develop into fruits. Answer: E 41) Which of the following types of plants are incapable of self-pollination? A) dioecious B) monoecious C) complete D) wind-pollinated E) insect-pollinated Answer: A 42) Recent research has shown that fertilization requires that carpels recognize pollen grains as "self or no self." For self-incompatibility, the system requires A) the rejection of no self-cells. B) the rejection of self-cells. C) carpel incompatibility with the egg cells. D) that the flowers be incomplete. E) the union of genetically identical sperm and egg cells. Answer: B 43) Genetic incompatibility does not affect A) the attraction of a suitable insect pollinator. B) the germination of the pollen on the stigma. C) the growth of the pollen tube in the style. D) the membrane permeability of cells. E) different individuals of the same species. Answer: A 44) Which of the following is a potential advantage of introducing apomixis into hybrid crop species? A) Cultivars would be better able to cope with a rapidly changing environment. B) They would have a larger potential genome than inbred crops. C) All of the desirable traits of the cultivar would be passed on to offspring. D) They would benefit from positive mutations in their DNA. E) It would be easier to introduce novel genes. Answer: C 45) Which of the following is true about vegetative reproduction? A) It involves both meiosis and mitosis to produce haploid and diploid cells. B) It produces vegetables and not fruits. C) It involves meiosis only. D) It can lead to genetically altered forms of the species. E) It produces clones of the parent plant. Answer: E 46) Which of the following is a true statement about clonal reproduction in plants? A) Clones of plants do not occur naturally. B) Cloning, although achieved in animals, has not been demonstrated in plants. C) Making cuttings of ornamental plants is a form of fragmentation. D) Reproduction of plants by cloning may be either sexual or asexual. E) Viable seeds can result from sexual reproduction only. Answer: C 47) Which of the following statements is true for a species that produces seeds by apomixis? A) The seed coat is made of diploid cells derived from the ovule of a flower. B) The embryo consists of diploid cells derived from fertilization of a haploid egg by a haploid sperm. C) The scutellum is the primary food storage tissue of the embryo. D) A haploid embryo is contained within the seed. E) The embryo of the seed is genetically distinct from the parent plant. Answer: A 48) Which of the following could be considered an evolutionary advantage of asexual reproduction in plants? A) increased success of progeny in a stable environment B) increased agricultural productivity in a rapidly changing environment C) maintenance and expansion of a large genome D) production of numerous progeny E) increased ability to adapt to a change in the environment Answer: A 49) The most immediate potential benefits of introducing genetically modified crops include all of the following except A) increasing the amount of land suitable for agriculture. B) creating crops with better potential for biofuel production. C) creating crops with better nutritional attributes. D) increasing crop yield. E) decreasing the mutation rate of certain genes. Answer: E 50) Biofuels are mainly produced by A) the breakdown of cell wall biopolymers into sugars that can be fermented. B) plants that convert hemicellulose into gasoline. C) the genetic engineering of ethanol-generating genes into plants. D) transgenic crops that have cell walls containing ethylene. E) plants that are easy to grow in arid environments. Answer: A 51) Which of the following is a scientific concern related to creating genetically modified crops? A) Herbicide resistance may spread to weedy species. B) Beneficial insects may be harmed by eating pest species. C) Their adaptive advantages would allow them to overpower natural ecosystems. D) The monetary costs of growing genetically modified plants are significantly greater than those of traditional breeding techniques. E) Genetically modified plants are less stable and may revert back to parental genotypes. Answer: A 52) All of the following genetic engineering strategies are being pursued with the goal of preventing transgene escape from genetically modified crops except A) the introduction of male sterility into crops. B) the creation of transgenic crops with apomictic seeds. C) the introduction of trangenes into the chloroplast DNA. D) the creation of crops with flowers that develop normally, but fail to open. E) the creation of transgenic crops that hybridize more easily. Answer: E 53) Which of the following statements is true of protoplast fusion? A) It occurs when the second sperm nucleus fuses with the polar nuclei in the embryo sac. B) It can be used to form new plant varieties by combining genomes from two plants. C) It is used to develop gene banks to preserve genetic variability. D) It is the method of test-tube cloning that produces whole plants from callus. E) It occurs within a callus that is developing in tissue culture. Answer: B 54) What effects would occur in a mutant of Arabidopsis that cannot synthesize GABA within its flowers? A) Pollen tube growth would not be directed toward the egg, and fertilization would not occur. B) The seeds from the flowers would be unable to break dormancy. C) The pollen grain would not form a pollen tube due to incompatibility with the pollen tube. D) The length of the style would be increased to the point where the growing pollen tube would be unable to reach the synergids. Answer: A 30.2 Art Questions The following questions refer to the diagram of an embryo sac of an angiosperm shown in Figure 30.1. Figure 30.1 1) Based on Figure 30.1, which cell(s), after fertilization, give(s) rise to the embryo plant? A) A B) B C) C D) D E) E Answer: B 2) Based on Figure 30.1, which cell(s) become(s) the triploid endosperm? A) A B) B C) C D) D E) E Answer: C 3) Based on Figure 30.1, which cell(s) guide(s) the pollen tube to the egg cell? A) A B) B C) C D) D E) E Answer: A 30.3 Scenario Questions 1) You are studying a plant from the Amazon rain forest that shows strong self-incompatibility. To characterize this reproductive mechanism, you would look for A) ribonuclease (RNAase) activity in stigma cells. B) RNA in the plants. C) pollen grains with very thick walls. D) carpels that cannot produce eggs by meiosis. E) systems of wind, but not insect, pollination. Answer: A 2) Regardless of where in the world a vineyard is located, in order for the winery to produce a Burgundy, it must use varietal grapes that originated in Burgundy, France. The most effective way for a new California grower to plant a vineyard to produce Burgundy is to A) plant seeds obtained from French varietal Burgundy grapes. B) transplant varietal Burgundy plants from France. C) acquire a tissue culture of varietal Burgundy grapes from France. D) cross French Burgundy grapes with native American grapes. E) graft varietal Burgundy grape scions onto native (Californian) root stocks. Answer: E 30.4 End-of-Chapter Questions 1) A seed develops from A) an ovum. B) a pollen grain. C) an ovule. D) an ovary. E) an embryo. Answer: C 2) A fruit is A) a mature ovary. B) a mature ovule. C) a seed plus its integuments. D) a fused carpel. E) an enlarged embryo sac. Answer: A 3) Double fertilization means that A) flowers must be pollinated twice to yield fruits and seeds. B) every egg must receive two sperm to produce an embryo. C) one sperm is needed to fertilize the egg, and a second sperm is needed to fertilize the polar nuclei. D) the egg of the embryo sac is diploid. E) every sperm has two nuclei. Answer: C 4) "Golden Rice" A) is resistant to various herbicides, making it practical to weed rice fields with those herbicides. B) is resistant to a virus that commonly attacks rice fields. C) includes bacterial genes that produce a toxin that reduces damage from insect pests. D) produces larger, golden grains that increase crop yields. E) contains daffodil genes that increase vitamin A content. Answer: E 5) Which statement concerning grafting is correct? A) Stocks and scions refer to twigs of different species. B) Stocks come from vines, but scions come from trees. C) Stocks provide root systems for grafting. D) Grafting creates new species. E) Stocks and scions must come from unrelated species. Answer: C 6) Some dioecious species have the XY genotype for male and XX for female. After double fertilization, what would be the genotypes of the embryos and endosperm nuclei? A) embryo X/endosperm XX or embryo Y/endosperm XY B) embryo XX/endosperm XX or embryo XY/endosperm XY C) embryo XX/endosperm XXX or embryo XY/endosperm XYY D) embryo XX/endosperm XXX or embryo XY/endosperm XXY E) embryo XY/endosperm XXX or embryo XX/endosperm XXY Answer: D 7) A small flower with green petals is most likely A) bee-pollinated. B) bird-pollinated. C) bat-pollinated. D) wind-pollinated. E) moth-pollinated. Answer: D 8) The pollen produced by wind-pollinated plants is often smaller than the pollen produced by animal-pollinated plants. A reason for this might be that A) wind-pollinated plants, in general, are smaller than animal-pollinated plants. B) wind-pollinated plants release pollen in the spring, before the plant has stored enough energy to make large pollen grains. C) small pollen grains can be carried farther by the wind. D) animal pollinators are more facile at picking up large pollen grains. E) wind-pollinated flowers don’t need large pollen grains because they don’t have to attract animal pollinators. Answer: C 9) The black dots that cover strawberries are actually individual fruits from a flower with multiple carpels. The fleshy and tasty portion of a strawberry derives from the receptacle of the flower. Therefore, a strawberry is A) both a multiple fruit and an aggregate fruit. B) both a multiple fruit and an accessory fruit. C) both a simple fruit and an aggregate fruit. D) both an aggregate fruit and an accessory fruit. E) a simple fruit with many seeds. Answer: D Test Bank for Campbell Biology in Focus Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert B. Jackson, Jane B. Reece 9780321813664, 9780321962751, 9780134710679
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