Chapters 36, 37, 38, and 39

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On average, how far do agricultural products travel from farm to plate in the United States? 100 miles 400 miles 800 miles 1100 miles 1400 miles	1400 miles
Today, it takes about ______ Calories of energy to produce about 1 Calorie of food. 2 20 55 90 125	55
When does Cognito Farm use antibiotics on its cattle? Monthly to prevent illness. Weekly to prevent illness. Only when they are sick. Daily to prevent illness. Never	Only when they are sick.
It has been estimated that confined animal feeding operations contribute to about _____ of world carbon dioxide emissions. 5% 15% 25% 35% 45%	15%
What is used at Cognito Farm to control fly larvae in the pasture? all natural organic pesticides chickens insect traps chemical pesticides ultraviolet radiation	chickens
Cognito Farm avoids washing chicken carcasses with __________, which is done at many packing plants in the United States. acetic acid calcium carbonate bleach hydrochloric acid salt water	bleach
Most of the mass of organic material of a plant comes from nitrogen. soil minerals. atmospheric oxygen. carbon dioxide. water.	carbon dioxide.
Micronutrients are needed in very small amounts because A.only the most actively growing regions of the plants require micronutrients. B.they play only a minor role in the growth and health of the plant. C.most are supplied in large enough quantities in seeds. D.most of them are mobile in the plant. E.most serve mainly as cofactors of enzymes.	E.most serve mainly as cofactors of enzymes.
Mycorrhizae enhance plant nutrition mainly by A.providing sugar to root cells, which have no chloroplasts. B.absorbing water and minerals through the fungal hyphae. C.converting atmospheric nitrogen to ammonia. D.stimulating the development of root hairs. enabling the roots to parasitize neighboring plants.	B.absorbing water and minerals through the fungal hyphae.
Epiphytes are A.fungi that form mutualistic associations with roots. B.plants that capture insects. C.nonphotosynthetic parasitic plants. D.plants that grow on other plants. E.fungi that attack plants	D.plants that grow on other plants.
Some of the problems associated with intensive irrigation include all but aquifer depletion. land subsidence. overfertilization. mineral runoff. soil salinization.	overfertilization.
A mineral deficiency is likely to affect older leaves more than younger leaves if A.the mineral is required for chlorophyll synthesis. B.the mineral is a micronutrient. C.the mineral is very mobile within the plant. D.the mineral is a macronutrient. E.the older leaves are in direct sunlight.	C.the mineral is very mobile within the plant.
We would expect the greatest difference in plant health between two groups of plants of the same species, one group with mycorrhizae and one group without mycorrhizae, in an environment A.where nitrogen-fixing bacteria are abundant. B.that has soil with poor drainage. C.in which the soil is relatively deficient in mineral nutrients. D.that has hot summers and cold winters. E.that is near a body of water, such as a pond or river.	C.in which the soil is relatively deficient in mineral nutrients.
Two groups of tomatoes were grown under laboratory conditions, one with humus added to the soil and one 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 the food in the decomposing leaves of the humus for energy to make chlorophyll. B.the humus contained minerals such as magnesium and iron, needed for the synthesis of chlorophyll. C.the heat released by the decomposing leaves of the humus caused more rapid growth and chlorophyll synthesis. D.the healthy plants absorbed chlorophyll from the humus. E.the humus made the soil more loosely packed, so water penetrated more easily to the roots.	B.the humus contained minerals such as magnesium and iron, needed for the synthesis of chlorophyll.
The specific relationship between a legume and its mutualistic Rhizobium strain probably depends on A.specific recognition between the chemical signals and signal receptors of the Rhizobium strain and legume species. 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.each legume having a chemical dialogue with a fungus. E.destruction of all incompatible Rhizobium strains by enzymes secreted from the legume’s roots.	A.specific recognition between the chemical signals and signal receptors of the Rhizobium strain and legume species.
How do plants obtain organic molecules? A.Plants take up organic molecules through their roots. B.Plants take in organic molecules through their stomata. C.Plants synthesize their own organic molecules.	C.Plants synthesize their own organic molecules.
If a wide-spectrum fungicide that kills all fungal species were used extensively in a forest, what effects would you expect the treatment to have on the forest vegetation? A.It would harm the few plants that benefit from mutualistic relationships with mycorrhizal fungi. B.It would benefit plants by killing off fungal pathogens. C.It would greatly reduce the ability of most plants to take up water and minerals from soil.	C.It would greatly reduce the ability of most plants to take up water and minerals from soil.
Select the correct statement(s) about plant nutrition. Select all that apply. A.Mineral deficiency symptoms vary with the mobility of the mineral within the plant. B.Plants can remain healthy despite micronutrient deficiencies because micronutrients are needed in such small quantities. C.As autotrophs, plants can synthesize all the nutrients they require.	A.Mineral deficiency symptoms vary with the mobility of the mineral within the plant.
How do prokaryotes contribute to plant health? Select all that apply. A.Prokaryotes fix atmospheric nitrogen. B.Prokaryotes form mycorrhizae, which transport water and minerals to plant roots. C.Prokaryotes secrete chemicals that stimulate plant growth and protect plant roots from disease.	A.Prokaryotes fix atmospheric nitrogen. C.Prokaryotes secrete chemicals that stimulate plant growth and protect plant roots from disease.
Identify the components of the rhizosphere, the soil layer that surrounds plant roots. Select all that apply. Dirt Bacteria Fungi	Dirt Bacteria Fungi
How big is the range of soil degradation observed between continents? about 50% about 15% about 22% about 7%	about 15%
Which continent likely represents the largest absolute land area experiencing degradation? Africa Asia North America Europe South America	Asia
For which continents is land degradation having the least impact on global grain production? Asia and Europe Africa and South America Africa and Asia North and South America Europe and North America	Africa and South America
Suppose you are advising the UN on global soil conservation projects. Limited resources force you to focus all your efforts on only one continent. Based on the information in the graph, which continent would you focus on so as to have the greatest impact on global grain production? Africa North America South America Europe Asia	Asia
Which continent has the largest proportion of land with more than moderate degradation? Africa North America Asia Europe South America	Africa
Assume that these categories represent a progression of degradation through time. In other words, if left unchecked, lightly degraded soil progresses into moderately degraded soil and so forth. Which continent poses the greatest concern for future loss of agricultural productivity? Asia South America North America Africa Europe	Europe
What name is given to the process seen in this animation? To view the animation, click here. Then click Start on the image to start the animation. cation exchange ion pumping anion exchange root hair exchange carbonation	cation exchange
The release of CO2 into the soil results in the formation of _____. A.hydrogen ions and oxygen ions B.carbonate ions and oxygen ions C.sodium ions and chloride ions D.hydrogen ions and carbonate ions E.potassium ions and calcium ions	D.hydrogen ions and carbonate ions
What process is the source of the CO2 that root hairs release into the soil? respiration respiration and photolysis photolysis photosynthesis and respiration photosynthesis	respiration
The binding of H+ ions to soil particles _____. A.is counteracted by acid precipitation B.displaces mineral cations C.displaces mineral anions D.promotes the clumping of soil particles E.displaces nitrates from soil particles	B.displaces mineral cations
Which of these ions is most likely to be leached from the soil? potassium ions chlorine ions calcium ions magnesium ions iron ions	chlorine ions
Acid precipitation _____. A.promotes the attachment of anions to soil particles B.has no effect on soil fertility C.decreases soil fertility D.increases soil fertility E.enhances the diffusion of cations into root hairs	C.decreases soil fertility
How do cations enter root hairs? phagocytosis endocytosis active transport diffusion osmosis	diffusion
Topsoil _____. A.does not retain water B.is a mixture of rock fragments, living organisms, and humus C.is devoid of charged particles D.is uniform in texture E.is the relatively inert upper layer of soil	B.is a mixture of rock fragments, living organisms, and humus
Humus consists of _____. A.mostly water and inorganic nutrients B.all of the organisms inhabiting the soil C.anions and cations found in the soil D.decomposing organic material E.strictly soil microbes	D.decomposing organic material
A major long-term problem resulting from excessive irrigation is the _____. A.excessive cooling of the soil B.erosion of fine soil particles C.drowning (anoxia) of crop plants D.encroachment of water-consuming weeds E.accumulation of salts in the soil	E.accumulation of salts in the soil
All of the following contributed to the dust bowl in the American southwest during the 1930s except A.lack of soil moisture. B.plowing of native grasses. C.planting of field crops. D.clear-cutting of forest trees. E.overgrazing by cattle.	D.clear-cutting of forest trees.
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" Item (A) is unrelated to item (B). Item (A) is less than item (B). Item (A) is exactly or very approximately equal to item (B). Item (A) is greater than item (B).	Item (A) is exactly or very approximately equal to item (B).
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 Item (A) is greater than item (B). Item (A) is less than item (B). Item (A) is exactly or very approximately equal to item (B). There is not enough information to make a meaningful comparison.	Item (A) is less than item (B).
Which of the following plant structures shares the most common features and functions with a fungal hyphae? lenticels prop roots vascular cambium stomata root hairs	Root hairs
If you wanted to increase the cation exchange and water retention capacity of loamy soil, what should you do? A.add fertilizer containing potassium, calcium, and magnesium to the soil B.add clay to the soil C.adjust the soil pH to 7.9 D.increase the number of sand particles in the soil E.practice no-till agriculture	B.add clay to the soil
Most of the water taken up by a plant is used to keep cells turgid. used as a solvent. lost during transpiration. converted to CO2. used as a hydrogen source in photosynthesis.	lost during transpiration.
There are several properties that are characteristic of a soil in which typical plants would grow well. Of the following, which would be the least conducive to plant growth? abundant humus compacted soil numerous soil organisms high porosity high cation exchange capacity	compacted soil
A soil well suited for the growth of most plants would have all of the following properties except abundant humus. air spaces. good drainage. a high pH. high cation exchange capacity.	a high pH.
Why does overwatering a plant kill it? A.Water does not have all the necessary minerals a plant needs to grow. B.Water supports the growth of root parasites. C.Water lowers the water potential of the roots. D.Water neutralizes the pH of the soil. E.The roots are deprived of oxygen.	E.The roots are deprived of oxygen.
Which of the following soil minerals is most likely leached away during a hard rain? NO3− H+ Ca2+ Na+ K+	NO3−
The NPK percentages on a package of fertilizer refer to the A.total protein content of the three major ingredients of the fertilizer. B.relative percentages of organic and inorganic nutrients in the fertilizer. C.proportions of three different nitrogen sources. D.percentages of manure collected from different types of animals. E.percentages of three important mineral nutrients.	E.percentages of three important mineral nutrients.
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.using plenty of the best fertilizers B.establishing an extensive irrigation system C.selecting crops adapted to arid areas D.converting hillsides into fields E.finding a way to sell all parts of crop plants	C.selecting crops adapted to arid areas
Most of the dry weight of a plant is the result of uptake of A.water and minerals through mycorrhizae. B.water and minerals through root hairs. C.CO2 through stoma. D.carbohydrates in the root hairs and concentration in the root cortex. E.CO2 and O2 through stomata in leaves.	C.CO2 through stoma.
In west Texas, cotton has become an important crop in the last several decades. However, in this hot, dry part of the country there is little rainfall, so farmers irrigate their cotton fields. They must also regularly fertilize the cotton fields because the soil is very sandy. The figure 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 question. Based on the information provided in the figure, 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.The rate of photosynthesis has declined due to irrigation. D.Water has accumulated in the soil due to irrigation. E.The soil water potential has become more negative due to salination.	E.The soil water potential has become more negative due to salination.
In west Texas, cotton has become an important crop in the last several decades. However, in this hot, dry part of the country there is little rainfall, so farmers irrigate their cotton fields. They must also regularly fertilize the cotton fields because the soil is very sandy. The figure 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 question. If you were the county agriculture agent, what would be the best advice you could give the farmer who owns the field under study in the figure? A.Continue to fertilize, but stop irrigating the field and rely on rainfall. B.Continue to irrigate, but stop fertilizing the field and rely on organic nutrients in the soil. C.Continue to fertilize and irrigate, but add the nitrogen-fixing bacteria Rhizobium to the irrigation water until the productivity increases. D.Add acid to the soil and increase its cation exchange capabilities so more nutrients are retained in the soil. E.Plant a variety of cotton that requires less water and can tolerate salinity.	E.Plant a variety of cotton that requires less water and can tolerate salinity.
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 Item (A) is larger than item (B). Item (A) bears no relationship to item (B). Item (A) is smaller than item (B). Item (A) is exactly or very approximately equal to item (B).	Item (A) is larger than item (B).
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 sulfur to lower the soil pH and precipitate the heavy metals C.inoculating soil with mycorrhizae to avoid heavy metal uptake D.adding plant species that have the ability to take up and accumulate heavy metals E.application of fertilizers to compete with heavy metal uptake	D.adding plant species that have the ability to take up and accumulate heavy metals
What are the largest particles formed from the breakdown of rock? Sand Clay Gravel Silt	Gravel
Which of the following is an elemental ion? HCO−3 K NO−3 K+	K+
True or false? Soil texture affects the amount of water available to plants; water is held best by clay and sand particles. True False	False
Which of the following steps occurs first during soil formation? Lichens grow on the rock surface. Organic material is added to the rock surface. Weathering of solid rock occurs. Mosses grow on the rock surface.	Weathering of solid rock occurs.
Why is the decomposition of dead organisms important for soil formation? A.The process increases the amount of silt in the soil. B.The process makes negatively charged ions more easily absorbed by plant roots. C.The process produces acidic compounds that dissolve the rock surface. D.The process adds organic matter to the soil, which is necessary to support the growth of larger plants.	D.The process adds organic matter to the soil, which is necessary to support the growth of larger plants.
Which of the following statements about nutrient uptake by plants is true? A.Plants require other elements besides carbon, hydrogen, and oxygen to grow, and they can obtain these in soil. B.Root hairs increase the volume of roots for more efficient absorption of water and nutrients. C.Plants can easily absorb mineral ions from soil with large amounts of organic matter. D.Positively charged ions remain dissolved in water and are easily absorbed by plant roots.	A.Plants require other elements besides carbon, hydrogen, and oxygen to grow, and they can obtain these in soil.
True or false? Plants use both active and passive transport processes to transport ions against their concentration gradients. True False	False
Mineral nutrients _____. A.are organic nutrients B.enter plants via the stomata C.contribute little to a plant’s overall mass D.are not essential to plant growth E.include sugars	C.contribute little to a plant’s overall mass
For an element to be considered a macronutrient _____. A.it must be a large atom B.it must have a high atomic mass C.it must be required in relatively large amounts D.it should consist of three or more subunits E.it must be available in large amounts	C.it must be required in relatively large amounts
Which of the following is a symptom of magnesium deficiency in plants? A.dieback of shoot tips B.yellowing of younger leaves prior to yellowing of older leaves C.chlorosis D.decreased transpiration E.excessive vegetative growth	C.chlorosis
Which of the following would be in the lowest concentration in an actively growing shoot tip? nitrogen potassium phosphorus zinc calcium	zinc
Most of the dry weight of a plant is derived from H2O and CO2. NO3− and CO2. H2O and K+. PO43− and K+. K+ and CO2.	H2O and CO2.
In hydroponic culture, what is the purpose of bubbling air into the solute? A.to provide CO2 for photosynthesis B.to inhibit the growth of anaerobic bacteria C.to inhibit the growth of aerobic algae D.to keep dissolved nutrients evenly distributed E.to provide oxygen to the root cells	E.to provide oxygen to the root cells
Which of the following essential nutrients plays an essential role in the opening and closing of the stomatal aperture? Bo K Fe H Mg	K
Which of the following is of least concern to a researcher in a mineral nutrition experiment? A.chemical inertness of the container used to make and store the nutrient solutions B.medium in which the test seedlings were grown C.ability of a laboratory balance to weigh very small quantities of chemicals D.purity of the chemicals used to make the nutrient solutions E.purity of the water used to make the nutrient solutions	C.ability of a laboratory balance to weigh very small quantities of chemicals
Which two elements make up more than 90% of the dry weight of plants? oxygen and hydrogen nitrogen and oxygen oxygen and carbon carbon and potassium carbon and nitrogen	oxygen and carbon
The bulk of a plant’s dry weight is derived from A.the uptake of organic nutrients from the soil. B.CO2. C.soil minerals. D.the hydrogen from H2O. E.the oxygen from H2O.	B.CO2.
Which of the following elements is incorrectly paired with its function in a plant? A.magnesium-component of chlorophyll; activates many enzymes B.phosphorus-component of nucleic acids, phospholipids, ATP, several coenzymes C.potassium-cofactor functional in protein synthesis, osmosis, operation of stomata D.sulfur-component of DNA; activates some enzymes E.nitrogen-component of nucleic acids, proteins, hormones, coenzymes	D.sulfur-component of DNA; activates some enzymes
Synthesis of which of the following compounds in a mature leaf would be least impacted by a temporary soil nitrogen deficiency? amino acids chlorophyll cellulose DNA RNA	cellulose
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 required to regenerate phosphoenolpyruvate in C4 and CAM plants D.to be active in amino acid formation E.to be a component of chlorophyll	E.to be a component of chlorophyll
Which of the following is not true of micronutrients in plants? A.They generally help in catalytic functions in the plant. B.They are required for a plant to grow from a seed and complete its life cycle. C.They are elements required in relatively small amounts. D.They are the essential elements of small size and molecular weight. E.Deficiencies vary widely by soil type.	D.They are the essential elements of small size and molecular weight.
If an African violet has chlorosis, which of the following elements might be a useful addition to the soil? chlorine iodine molybdenum magnesium copper	magnesium
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.	A.is a relatively immobile nutrient in plants.
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? 1 kg 4 grams 40 grams 960 grams 1 gram	960 grams
A group of 10 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.buildup of toxic substances in the tray. B.anoxia. C.organic nutrient depletion. D.no room left for root growth. E.competition for resources.	B.anoxia.
Which of the following elements, is required for the stability of cell walls? zinc chlorine calcium molybdenum manganese	calcium
Reddish-purple coloring of leaves, especially along the margins of young leaves, is a typical symptom of deficiency of which element? P N C K+ Mg2+	P
A corn (Zea mays) mutant is developed that is impaired in magnesium uptake. The most likely phenotypic expression would be A.a reduction in leaf surface area. B.a delay in flowering. C.chlorosis, especially in the older leaves. D.severely stunted root growth and branching. E.a purple tinge to actively growing shoots.	C.chlorosis, especially in the older leaves.
Which of the following statements correctly describe nitrogen and its role as a plant nutrient? Select all that apply. A.Nitrogen is a component of starches. B.Nitrogen deficiency usually causes plant leaves to turn purple. C.Nitrogen is a macronutrient in plants. D.Plants can directly absorb atmospheric nitrogen (N2). E.Nitrogen-fixing bacteria in the soil convert N2 to NH3. F.Plant roots can only absorb nitrogen in the form of ammonium ions (NH4+) or nitrate ions (NO3−). G.Nitrogen is a component of nucleic acids, proteins, hormones, and coenzymes. H.Nitrogen deficiency usually causes plant leaves to turn yellow. I.Nitrogen is a micronutrient in plants.	C.Nitrogen is a macronutrient in plants. E.Nitrogen-fixing bacteria in the soil convert N2 to NH3. F.Plant roots can only absorb nitrogen in the form of ammonium ions (NH4+) or nitrate ions (NO3−). G.Nitrogen is a component of nucleic acids, proteins, hormones, and coenzymes. H.Nitrogen deficiency usually causes plant leaves to turn yellow.
Nitrogen-fixing bacteria in the soil _____. A.convert atmospheric nitrogen to ammonia B.use nitrates to make amino acids that plants can use C.change ammonium into nitrates D.convert nitrate to ammonium E.convert nitrates to N2	A.convert atmospheric nitrogen to ammonia
The relationship between legumes and Rhizobium is _____. parasitic predatory commensalistic competitive mutualistic	mutualistic
Mutualistic associations between roots and soil fungi are called _____. mycorrhizae phytoremediators cation exchange Casparian strips nitrogen fixation	mycorrhizae
The sundew plant has to digest insects because _____. A.it obtains nitrogen from their bodies that it cannot get from the soil B.it has lost the ability to perform photosynthesis C.it’s a method of self-cleaning to rid the plants of insects that get stuck in the plant D.it lives in a dry environment and uses moisture from the insects’ bodies E.its flowers are fertilized by pollen in its digestive tract	A.it obtains nitrogen from their bodies that it cannot get from the soil
Nitrogen fixation is a process that A.converts nitrogen gas into ammonia. B.releases nitrate from the rock substrate. C.recycles nitrogen compounds from dead and decaying materials, and converts ammonia to ammonium. D.recycles nitrogen compounds from dead and decaying materials. E.converts ammonia to ammonium.	A.converts nitrogen gas into ammonia.
Why is nitrogen fixation an essential process? A.Nitrogen fixers are sometimes symbiotic with legumes. B.Nitrogen fixation can only be done by certain prokaryotes. C.Nitrogen-fixing capacity can be genetically engineered. D.Fixed nitrogen is often the limiting factor in plant growth. E.Nitrogen fixation is very expensive in terms of metabolic energy.	D.Fixed nitrogen is often the limiting factor in plant growth.
In what way do nitrogen compounds differ from other minerals needed by plants? A.Only nitrogen requires the action of bacteria to be made available to plants. B.Only nitrogen can be absorbed by root hairs. C.Only nitrogen is held by cation exchange capacity in the soil. D.Only nitrogen can be lost from the soil. E.Only nitrogen is needed for protein synthesis.	A.Only nitrogen requires the action of bacteria to be made available to plants.
Which of the following, if used as a fertilizer, would be most immediately available for plant uptake? NO3 amino acids CN2H2 N2 NH3	NO3
The enzyme complex nitrogenase catalyzes the reaction that reduces atmospheric nitrogen to NO2. NO−. NH3. NO+. N2.	NH3.
In a root nodule, the gene coding for nitrogenase A.is part of the Rhizobium genome. B.is absent in active bacteroids. C.is inactivated by leghemoglobin. D.protects the nodule from nitrogen. E.is found in the cells of the pericycle.	A.is part of the Rhizobium genome.
The most efficient way to increase essential amino acids in crop plants for human consumption would be to A.use 20-20-20 fertilizer instead of 20-5-5 fertilizer. B.breed for higher yield of deficient amino acids. C.engineer nitrogen-fixing nodules into crop plants lacking them. D.increase the amount of fertilizer used on fields. E.increase irrigation of nitrogen-fixing crops.	B.breed for higher yield of deficient amino acids.
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 developing offshoots from the root. C.are benefiting from a mutualistic bacterium. D.contain developing insect pupa. E.are infected with a parasite.	C.are benefiting from a mutualistic bacterium.
Which of the following is a true statement about nitrogen fixation in root nodules? A.The process is relatively inexpensive in terms of ATP costs. B.The plant contributes the nitrogenase enzyme. 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.Leghemoglobin helps maintain a low O2 concentration within the nodule.
Upregulation of leghemoglobin biosynthesis in a leguminous species would most likely indicate A.the plant is suffering from a mineral deficiency. B.the plant has been infected with mycorrhizae. C.the plant is suffering from water stress. D.the successful inoculation of nitrogen-fixing bacteria. E.an increase in the biosynthesis of amino acids.	D.the successful inoculation of nitrogen-fixing bacteria.
Which of the following is not a function of rhizobacteria? A.produce hormones that stimulate plant growth B.carry out nitrogen fixation C.absorb toxic metals D.produce antibiotics that protect roots from disease E.supply growing roots with glucose	E.supply growing roots with glucose
An example of a mutualistic association between a plant and a fungus would be assisted pollination. nitrogen fixation. mycorrhizae. parasitic infection. Rhizobium infection.	mycorrhizae.
Hyphae form a covering over roots. These hyphae create a large surface area that helps to do which of the following? A.anchor a plant B.protect the roots from ultraviolet light C.aid in absorbing minerals and ions D.maintain cell shape E.increase cellular respiration	C.aid in absorbing minerals and ions
Which of the following is a primary difference between ectomycorrhizae and endomycorrhizae? A.Ectomycorrhizae do not penetrate root cells, whereas endomycorrhizae grow into invaginations of the root cell membranes. B.Endomycorrhizae have thicker, shorter hyphae than ectomycorrhizae. C.Endomycorrhizae, but not ectomycorrhizae, form a dense sheath over the surface of the root. 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.	A.Ectomycorrhizae do not penetrate root cells, whereas endomycorrhizae grow into invaginations of the root cell membranes.
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 across the cuticle of the rhizome. C.diffusion through stomata. D.osmosis through the root hairs. E.absorption by mycorrhizae.	E.absorption by mycorrhizae.
What are epiphytes? A.haustoria used for anchoring to host plants and obtaining xylem sap B.plants that live in poor soil and digest insects to obtain nitrogen C.aerial vines common in tropical regions D.plants that have a symbiotic relationship with fungi E.plants that grow on other plants but do not obtain nutrients from their hosts	E.plants that grow on other plants but do not obtain nutrients from their hosts
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 energy. minerals. water. carbohydrates. lipids and steroids.	minerals.
Rhizobia and mycorrhizae share all of the following features except A.they both are found in most ecosystems of the world. B.many are host-specific. C.they both enhance the growth of most plants. D.they both benefit by receiving carbohydrate from the plant. E.they both become parasitic in nutrient-rich environments	E.they both become parasitic in nutrient-rich environments
Rhizobia, actinomycetes, and cyanobacteria all share the common feature that they can A.exist in extreme environments. B.increase water uptake in plants. C.kill parasites in the soil. D.increase nutrient availability in the soil for plants. E.fix atmospheric nitrogen.	E.fix atmospheric nitrogen.
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), 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 sterile soil were stunted due to overfertilization. B.the plants transplanted into the nonsterile soil received more fertilizer. C.the plants transplanted into sterile soil suffered anoxia from improper water drainage. D.the plants transplanted into the nonsterile soil were inoculated with mycorrhizae.	D.the plants transplanted into the nonsterile soil were inoculated with mycorrhizae.
If a plant is infected with nitrogen-fixing bacteria, what is the most probable effect on the plant? A.It gets chlorosis B.It becomes flaccid due to the loss of water and nutrients from the roots. C.It dies. D.It will likely grow faster than an uninfected plant. E.It will have a higher concentration of N2 in its roots and shoots..	D.It will likely grow faster than an uninfected plant.
A rootless, green plant is found growing on the branches and trunks of rainforest trees, but lacks any apparent adaptation for collecting rainwater. This plant is most likely a carnivorous plant. a parasite. a symbiotic plant. a nitrogen-fixing plant. an epiphyte.	a parasite.
The symplast transports all of the following except mRNA. sugars. proteins. DNA. viruses.	DNA.
Which of the following is an adaptation that enhances the uptake of water and minerals by roots? A.rhythmic contractions by cortical cells B.pumping through plasmodesmata C.mycorrhizae D.active uptake by vessel elements E.cavitation	C.mycorrhizae
Which structure or compartment is part of the symplast? A.an extracellular air space B.the cell wall of a mesophyll cell C.the interior of a vessel element D.the interior of a sieve tube E.the cell wall of a root hair	D.the interior of a sieve tube
Movement of phloem sap from a source to a sink A.occurs through the apoplast of sieve-tube elements. B.results mainly from diffusion. C.depends on pumping water into sieve tubes at the source. D.depends on tension, or negative pressure potential. E.depends ultimately on the activity of proton pumps.	E.depends ultimately on the activity of proton pumps.
Photosynthesis ceases when leaves wilt, mainly because A.the chlorophyll in wilting leaves is degraded. B.photolysis, the water-splitting step of photosynthesis, cannot occur when there is a water deficiency. C.stomata close, preventing CO2 from entering the leaf. D.accumulation of CO2 in the leaf inhibits enzymes. E.flaccid mesophyll cells are incapable of photosynthesis.	C.stomata close, preventing CO2 from entering the leaf.
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.increasing the ψ of the cytoplasm D.positive pressure on the surrounding solution E.the loss of solutes from the cell	D.positive pressure on the surrounding solution
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 ψp of +0.35 MPa. ψ of -0.65 MPa. ψp of +0.30 MPa. ψp of +0.65 MPa. ψ of 0 MPa.	ψp of +0.35 MPa.
Compared with a cell with few aquaporin proteins in its membrane, a cell containing many aquaporin proteins will A.have a higher water potential. B.have a faster rate of active transport. C.have a lower water potential. D.have a faster rate of osmosis. E.accumulate water by active transport.	D.have a faster rate of osmosis.
Which of the following would tend to increase transpiration? a rainstorm higher stomatal density sunken stomata a thicker cuticle spiny leaves	higher stomatal density
Select the accurate statement about water potential. A.Water in a turgid cell has positive pressure potential. B.Free water moves from a region of lower water potential to a region of higher water potential. C.Adding solutes to water increases water potential.	A.Water in a turgid cell has positive pressure potential.
Select the correct mechanism of stomatal opening and closing. A.The cell walls of guard cells are thickened on the side of the stomatal opening and the thinner walls bow outward when the guard cells become turgid, to close the stomata. B.The radial orientation of cellulose microfibrils in the cell walls of guard cells causes them to bow outward and open the stomatal pore when turgid. C.Light stimulates proton pumps in the plasma membrane of the guard cells, causing them to lose K+ and become flaccid.	B.The radial orientation of cellulose microfibrils in the cell walls of guard cells causes them to bow outward and open the stomatal pore when turgid.
A plant cell is placed in distilled water, as shown in the figure. There is a net uptake of water by osmosis, causing the cell to become turgid. Select the correct statement about this setup, after the cell is fully turgid. A.The water potentials (Ψ) of the cell and its surroundings are the same. B.Because the cell contains more solutes than the distilled water that surrounds it, the solute potential (ΨS) of the cell is higher than the solute potential of distilled water. C.The pressure potentials (ΨP) of the cell and its surroundings are the same.	A.The water potentials (Ψ) of the cell and its surroundings are the same.
Select the correct statement about variation in stomatal density. A.Stomatal density is developmentally plastic. B.Stomatal density is fully under genetic control. C.Stomatal density increases with increasing atmospheric CO2 level.	A.Stomatal density is developmentally plastic.
If a plant’s stomata are closed and no transpiration is occurring, which of the following predictions is accurate? A.Without transpiration, less water will be absorbed from the soil. B.Without transpiration, the plant will be water deficient. C.Without transpiration, the plant’s cells will become flaccid.	A.Without transpiration, less water will be absorbed from the soil.
Plants must always compromise between _____ and _____. A.maximizing transport of minerals … minimizing transport of sugars B.maximizing access to light … minimizing intake of CO2 C.maximizing photosynthesis … minimizing water loss D.maximizing water loss … minimizing H+ protons E.maximizing water absorption … minimizing leaf area	C.maximizing photosynthesis … minimizing water loss
Mycorrhizae are _____. A.structures that promote self-pruning in plants B.mutualistic associations between plant roots and fungi C.structures that minimize water loss from leaves D.a type of leaf found in perennial grasses E.mutualistic associations between plants and nitrogen-fixing bacteria	B.mutualistic associations between plant roots and fungi
All of the following are plant adaptations to life on land except tracheids and vessels. collenchyma. root hairs. cuticle. the Calvin cycle of photosynthesis.	the Calvin cycle of photosynthesis.
The ancestors of land plants were aquatic algae. Which of the following is not an evolutionary adaptation to life on land? C3 photosynthesis a waxy cuticle root hairs xylem and phloem guard cells	C3 photosynthesis
A plant developed a mineral deficiency after being treated with a fungicide. What is the most probable cause of the deficiency? A.Mycorrhizal fungi were killed. B.Active transport of minerals was inhibited. C.The genes for the synthesis of transport proteins were destroyed. D.Proton pumps reversed the membrane potential. E.Mineral receptor proteins in the plant membrane were not functioning.	A.Mycorrhizal fungi were killed.
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.tall plants; higher leaf area index B.bushier plants; lower leaf area index C.short plants; lower leaf area index D.bushier plants; higher leaf area indexes E.tall plants; lower leaf area index	D.bushier plants; higher leaf area indexes
Which structure or compartment is not part of the plant’s apoplast? A.the lumen of a sieve tube B.the cell wall of a transfer cell C.the cell wall of a mesophyll cell D.the cell wall of a root hair E.the lumen of a xylem vessel	A.the lumen of a sieve tube
Which of the following would be least likely to affect osmosis in plants? A.receptor proteins in the membrane B.a difference in water potential C.proton pumps in the membrane D.aquaporins E.a difference in solute concentrations	A.receptor proteins in the membrane
Which of the following is not a function of the plasma membrane proton pump? A.hydrolyzes ATP B.equalizes the charge on each side of a membrane C.generates a membrane potential D.produces a proton gradient E.stores potential energy on one side of a membrane	B.equalizes the charge on each side of a membrane
Given that early land plants most likely share a common ancestor with green algae, the earliest land plants were most likely A.vascular plants with well-defined root systems. B.plants with well-developed leaves. C.species with a well-developed, thick cuticle. D.nonvascular plants that grew leafless photosynthetic shoots above the shallow fresh water in which they lived. E.species that did not exhibit alternation of generations.	D.nonvascular plants that grew leafless photosynthetic shoots above the shallow fresh water in which they lived.
An open beaker of pure water has a water potential (Ψ) of +0.23 MPa. 0.0 (zero). +0.07 MPa. -0.23 MPa. -0.0000001 MPa.	0.0 (zero).
All of the following have an effect on water potential (Ψ) in plants except dissolved solutes. physical pressure. DNA structure. water-attracting matrices. osmosis.	DNA structure.
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 in both directions and the concentrations would remain equal. B.be from the sucrose solution into the tissue. C.be impossible to determine from the values given here. D.be from the tissue into the sucrose solution. E.occur only as ATP was hydrolyzed in the tissue.	D.be from the tissue into the sucrose solution.
Compared to a cell with few aquaporins in its membrane, a cell containing many aquaporins will A.have a lower water potential. B.have a faster rate of active transport. C.be flaccid. D.have a faster rate of osmosis. E.have a higher water potential.	D.have a faster rate of osmosis.
Which of the following statements is false about bulk flow? A.It may be the result of either positive or negative pressure potential. B.It depends on a difference in pressure potential at the source and sink. C.It is more effective than diffusion over distances greater than 100 μm. D.It is driven primarily by pressure potential. E.It depends on the force of gravity on a column of water.	E.It depends on the force of gravity on a column of water.
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.fibrous arrangement of the roots B.endodermis C.mycorrhizae D.fungi associated with the roots E.root hairs	B.endodermis
Root hairs are most important to a plant because they A.contain xylem tissue. B.provide a habitat for nitrogen-fixing bacteria. C.increase the surface area for absorption. D.anchor a plant in the soil. E.store starches.	C.increase the surface area for absorption.
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? the endodermis the root epidermis the Casparian strip the root cortex a guard cell	the endodermis
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 tropical rain forest a large, still pond a dry, sandy region an oasis within a grassland the floor of a deciduous forest	a tropical rain forest
Active transport involves all of the following except A.pumping of solutes across the membrane. B.transport of solute against a concentration gradient. C.hydrolysis of ATP. D.diffusion of solute through the lipid bilayer of a membrane. E.specific transport proteins in the membrane.	D.diffusion of solute through the lipid bilayer of a membrane.
Active transport of various materials in plants at the cellular level requires all of the following except a proton gradient. a membrane potential. ATP. transport proteins xylem membranes.	xylem membranes.
The movement of water across biological membranes can best be predicted by A.prevailing weather conditions. B.level of active transport. C.water potentials. D.aquaporins. E.negative charges in the cell wall.	C.water potentials.
If ΨP = 0.3 MPa and ΨS = -0.45 MPa, the resulting Ψ is -0.75 MPa. -0.42 MPa. +0.15 MPa. +0.75 MPa. -0.15 MPa.	-0.15 MPa.
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? cell wall cytosol cell membrane vacuole plasmodesmata	plasmodesmata
The proton pump _____. A.uses the energy of a proton gradient to generate ATP B.releases kinetic energy C.uses the energy stored in ATP to produce a hydrogen ion gradient across membranes. D.is a passive process E.operates by osmosis	C.uses the energy stored in ATP to produce a hydrogen ion gradient across membranes.
A plant cell placed in a solution with a lower (more negative) water potential will _____. A.gain water and become turgid B.lose water and become turgid C.lose water and plasmolyze D.lose water and burst E.gain water and plasmolyze	C.lose water and plasmolyze
Which of the following statements about xylem is incorrect? A.No energy input is required for transport. B.It typically has a lower water potential than is found in soil. C.The conducting cells are part of the apoplast. D.It transports mainly sugars and amino acids. E.It conducts material from root tips to leaves.	D.It transports mainly sugars and amino acids.
What is the role of proton pumps in root hair cells? A.eliminate excess electrons B.pressurize xylem transport C.maintain the H+ gradient D.establish ATP gradients E.assist in active uptake of water molecules	C.maintain the H+ gradient
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 increased surface area for the absorption of mineral nutrients. C.It ensures that all water and dissolved substances must pass through a cell membrane before entering the stele. D.It ensures that all minerals are absorbed from the soil in equal amounts. E.It provides energy for the active transport of minerals into the stele from the cortex.	C.It ensures that all water and dissolved substances must pass through a cell membrane before entering the stele.
Which of the following is not an important component of the long-distance transport process in plants? A.a negative water potential B.the root parenchyma C.the cohesion of water molecules D.the active transport of solutes E.bulk flow from source to sink	B.the root parenchyma
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.sterilization removes essential nutrients from the soil. B.the sterilization process kills the root hairs as they emerge from the seedling. C.water and mineral uptake is faster when mycorrhizae are present. D.the normal symbiotic fungi are not present in the sterilized soil. E.the normal symbiotic fungi are not present in the sterilized soil, and water and mineral uptake is faster when mycorrhizae are present.	E.the normal symbiotic fungi are not present in the sterilized soil, and water and mineral uptake is faster when mycorrhizae are present.
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.bulk flow of water in the root apoplast B.cohesion among water molecules C.concentration of ions in the symplast D.evaporation of water from leaves E.capillarity of water within the xylem	C.concentration of ions in the symplast
One is most likely to see guttation in small plants when the A.preceding evening was hot, windy, and dry. B.transpiration rates are high. C.roots are not absorbing minerals from the soil. D.water potential in the stele of the root is high. E.root pressure exceeds transpiration pull.	E.root pressure exceeds transpiration pull.
One would expect to find the highest density of aquaporins in which of the following? A.the membrane lining plasmodesmata B.the pits of a tracheid C.the plasma membrane of a mature mesophyll cell in a leaf D.the plasma membrane of guard cells E.the plasma membrane of parenchyma cells in a ripe fruit	D.the plasma membrane of guard cells
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 cell walls would rupture, killing the cells. B.The osmotic pressure of the cells would decrease. C.Solutes would move out of the cells. D.The pressure potential of the cells would increase. E.Water would move out of the cells.	D.The pressure potential of the cells would increase.
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.The proton gradient would dissipate. B.Stomatal apertures would decrease. C.Transpiration would increase. D.The leaves would become more turgid. E.The uptake of CO2 would be enhanced.	B.Stomatal apertures would decrease.
All of the following involve active transport across membranes except A.the movement of K+ across guard cell membranes during stomatal opening. B.the movement of mineral nutrients from mesophyll cells into xylem cells. C.the movement of mineral nutrients into cells of the root cortex. D.the movement of sugar from one sieve-tube element to the next. E.the movement of mineral nutrients from the apoplast to the symplast.	D.the movement of sugar from one sieve-tube element to the next.
Which of these are symbiotic associations? Casparian strips mycorrhizae apoplasts root hairs symplast	mycorrhizae
In roots the _____ forces water and solutes to pass through the plasma membranes of _____ cells before entering the _____. A.Casparian strip … endodermis … xylem B.transpiration … endodermis … xylem C.Casparian strip … endodermis … phloem D.Casparian strip … ectoderm … xylem E.xylem … endodermis … Casparian strip	A.Casparian strip … endodermis … xylem
_____ provide(s) the major force for the movement of water and solutes from roots to leaves. Translocation Transfer cells Bulk flow Root pressure Transpiration	Transpiration
_____ bonds are responsible for the cohesion of water molecules. Nonpolar covalent Polar covalent Ionic Peptide Hydrogen	Hydrogen
_____ cells are the cells that regulate the opening and closing of stomata, thus playing a role in regulating transpiration. Casparian strip Tracheid Guard Companion Sieve-tube member	Guard
Which of the following is a correct statement about a difference between xylem and phloem transport? A.Transpiration moves phloem sap but not xylem sap. B.Active transport moves xylem sap but not phloem sap. C.Xylem sap moves up; phloem sap moves up or down. D.Phloem carries water and minerals; xylem carries organic molecules. E.Xylem sap moves from sugar source to sink, but phloem sap does not.	C.Xylem sap moves up; phloem sap moves up or down.
A student is performing a chemical analysis of xylem sap. This student should not expect to find much _____. sugar potassium nitrogen water phosphorus	sugar
What drives the flow of water through the xylem? A.active transport by tracheid and vessel elements B.passive transport by the endodermis C.active transport by sieve-tube elements D.the number of companion cells in the phloem E.the evaporation of water from the leaves	E.the evaporation of water from the leaves
What is the main force by which most of the water within xylem vessels moves toward the top of a tree? A.osmosis in the root B.active transport of ions into the stele C.the force of root pressure D.evaporation of water through stoma E.atmospheric pressure on roots	D.evaporation of water through stoma
In which plant cell or tissue would the pressure component of water potential most often be negative? leaf mesophyll cell root epidermis stem xylem stem phloem root cortex cell	stem xylem
Water potential is generally most negative in which of the following parts of a plant? xylem vessels in roots root hairs xylem vessels in leaves cells of the root cortex mesophyll cells of the leaf	mesophyll cells of the leaf
Which of the following has the lowest (most negative) water potential? leaf air spaces trunk xylem leaf cell walls root xylem root cortical cells	leaf air spaces
Transpiration in plants requires all of the following except A.active transport through xylem cells. B.evaporation of water molecules. C.adhesion of water molecules to cellulose. D.cohesion between water molecules. E.transport through tracheids.	A.active transport through xylem cells.
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.Gymnosperms can sometimes develop especially high root pressure, which may account for the rise of water in tall pine trees without transpiration pull. E.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.	D.Gymnosperms can sometimes develop especially high root pressure, which may account for the rise of water in tall pine trees without transpiration pull.
Active transport would be least important in the normal functioning of which of the following plant tissue types? leaf transfer cells root endodermal cells leaf mesophyll cells root sieve-tube elements stem tracheids and vessel elements	stem tracheids and vessel elements
Water rises in plants primarily by cohesion-tension. Which of the following is not true about the cohesion-tension model? A.The physical forces in the capillary-sized xylem cells make it easier to overcome gravity. B.Water loss (transpiration) is the driving force for water movement. C.Cohesion represents the tendency for water molecules to stick together by hydrogen bonds. D.The "tension" of this model represents the excitability of the xylem cells. E.The water potential of the air is more negative than the xylem.	D.The "tension" of this model represents the excitability of the xylem cells.
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 phloem loading. photosynthesis. cellular respiration. stomatal opening. xylem transport.	xylem transport.
Which cells in a root form a protective barrier to the vascular system where all materials must move through the symplast? pericycle epidermis exodermis cortex endodermis	endodermis
The following photo shows a strawberry leaf displaying guttation. Answer the following question regarding guttation. What is the main cause of guttation in plants? plant injury pressure flow in phloem root pressure transpiration condensation of atmospheric water	root pressure
Which of the following statements is false concerning the xylem? A.Movement of materials is by mass flow; solutes in xylem sap move due to a positive turgor pressure gradient from source to sink. B.Xylem tracheids and vessels fulfill their vital function only after their death. C.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. D.The cell walls of the tracheids are greatly strengthened with lignin and cellulose fibrils forming thickened rings or spirals. E.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.	A.Movement of materials is by mass flow; solutes in xylem sap move due to a positive turgor pressure gradient from source to sink.
Transpiration provides the driving force for the movement of water from the soil to the highest leaves of plants. Transpiration is also linked to other processes in plants, including photosynthesis and the transport of mineral nutrients. Which of the following statements correctly describe(s) a relationship between transpiration and other processes in plants? Select all that apply. A.Water is pulled from the roots to the leaves by transpiration, whereas mineral nutrients diffuse from the roots to the leaves. B.Open stomata provide a low-resistance pathway for CO2 to enter and for water to exit the leaf. C.The large surface area exposed to air inside the leaf maximizes the plant’s ability to absorb CO2 while minimizing water loss through transpiration. D.In most plants, the highest rate of transpiration occurs when the rate of photosynthesis is also highest. E.To minimize water loss during dry conditions, most plants must also restrict their ability to carry out photosynthesis. F.Transpiration is important in cooling leaves on warm, sunny days.	B.Open stomata provide a low-resistance pathway for CO2 to enter and for water to exit the leaf. D.In most plants, the highest rate of transpiration occurs when the rate of photosynthesis is also highest. E.To minimize water loss during dry conditions, most plants must also restrict their ability to carry out photosynthesis. F.Transpiration is important in cooling leaves on warm, sunny days.
Which one of the following refers to the loss of water through the stomata in a plant’s leaves? transpiration guttation bulk flow respiration osmosis	transpiration
Xerophytes minimize water loss by _____. A.using the CAM pathway B.having leaves with a large surface-to-volume ratio C.developing a Casparian strip between their leaves and stem D.using the C3 pathway E.reducing the thickness of the leaf cuticle	A.using the CAM pathway
All of the following normally enter the plant through the roots except nitrogen. water. potassium. carbon dioxide. calcium.	carbon dioxide.
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 only evaporative cooling and mineral transport. increased growth, increased turgor. evaporative cooling. mineral transport.	only evaporative cooling and mineral transport.
Ignoring all other factors, what kind of day would result in the fastest delivery of water and minerals to the leaves of a tree? warm, humid day cool, dry day very hot, dry, windy day warm, dry day cool, humid day	warm, dry day
The opening of stomata is thought to involve A.decreased turgor pressure in guard cells. B.movement of K+ from the guard cells. C.an increase in the solute concentration of the guard cells. D.a decrease in the solute concentration of the stoma. E.active transport of water out of the guard cells.	C.an increase in the solute concentration of the guard cells.
Which of the following experimental procedures would most likely reduce transpiration while allowing the normal growth of a plant? A.putting the plant in drier soil B.increasing the level of carbon dioxide around the plant C.decreasing the relative humidity around the plant D.subjecting the leaves of the plant to a partial vacuum E.injecting potassium ions into the guard cells of the plant	B.increasing the level of carbon dioxide around the plant
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.small, thick leaves with stomata on the lower surface B.plants that do not produce abscisic acid and have a short, thick taproot C.large, fleshy stems with the ability to carry out photosynthesis D.CAM plants that grow rapidly E.a thick cuticle on fleshy leaves	B.plants that do not produce abscisic acid and have a short, thick taproot
Guard cells do which of the following? A.protect the endodermis B.contain chloroplasts that import K+ directly into the cells C.help balance the photosynthesis-transpiration compromise D.accumulate K+ and in order to close the stomata E.guard against mineral loss through the stomata	C.help balance the photosynthesis-transpiration compromise
Photosynthesis begins to decline when leaves wilt because A.extreme heat causes photosynthetic enzymes to denature B.there is insufficient water for photolysis during the light reactions. C.stomata close, restricting CO2 entry into the leaf. D.CO2 accumulates in the leaves and inhibits the enzymes needed for photosynthesis. E.chloroplasts within wilted leaves are incapable of photosynthesis.	C.stomata close, restricting CO2 entry into the leaf.
All of the following are adaptations that help reduce water loss from a plant except photosynthesis. crassulacean acid metabolism. sunken stomata. transpiration. small, thick leaves.	transpiration.
Which tissue acts as a filter on the water absorbed by root hairs? Epidermis Vascular tissue Cortex Endodermis	Endodermis
True or false? Root pressure can move water a long distance up the xylem because of the higher water potential of the xylem in comparison to the water potential in the surrounding cells. True False	False
Which of the following statements about the distribution of sap throughout a plant is true? A.The mechanism that explains the movement of sugars throughout a plant is called the pressure-flow hypothesis. B.Companion cells form the conducting tissue for sap. C.The driving force for sugar movement is transpiration. D.The main component of phloem sap is glucose.	A.The mechanism that explains the movement of sugars throughout a plant is called the pressure-flow hypothesis.
Which term describes an area where sugars are used or stored? Leaves Sink Source Stomata	Sink
Which of the following statements about xylem transport is true? A.The xylem cells that conduct water and minerals are alive. B.Water and minerals move through the root cortex into the xylem and upward through the stem and into leaves. C.All water transported by the xylem is used for photosynthesis in the leaves. D.Water and minerals enter the xylem by diffusion.	B.Water and minerals move through the root cortex into the xylem and upward through the stem and into leaves.
What characterizes the rates of photosynthesis and transport in a plant on a dry cloudy day? A.Both the photosynthesis and transpiration rates are low. B.Both the photosynthesis and transpiration rates are high. C.The photosynthesis rate is low and stomata are open. D.The photosynthesis rate is high and phloem transport rates are low.	A.Both the photosynthesis and transpiration rates are low.
True or false? The rate of sugar transport in a plant depends on the rate of photosynthesis, the rate of transpiration, and the difference in turgor pressure between the source and the sink. True False	False
The solute most abundant in phloem sap is _____. amino acids sugar water hormones minerals	sugar
What is the driving force for the movement of solutes in the phloem of plants? A.gravity B.adhesion of water to phloem sieve tubes C.transpiration of water through the stomata D.root pressure E.a difference in water potential (Ψ) between the source and the sink	E.a difference in water potential (Ψ) between the source and the sink
Phloem transport of sucrose is often described as going from source to sink. Which of the following would not normally function as a sink? storage organ in summer mature leaf shoot tip growing leaf growing root	mature leaf
Which of the following is a correct statement about sugar movement in phloem? A.Diffusion can account for the observed rates of transport. B.Sugar is translocated from sinks to sources. C.Only phloem cells with nuclei can perform sugar movement. D.Movement can occur both upward and downward in the plant. E.Sugar transport does not require energy.	D.Movement can occur both upward and downward in the plant.
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.proteins; root; leaf C.nucleic acids; flower; root D.sugars; leaf; apical meristem E.sugars; stem; root	D.sugars; leaf; apical meristem
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. 2, 4, 3, 1, 5 2, 4, 1, 3, 5 2, 1, 4, 3, 5 1, 2, 3, 4, 5 4, 2, 1, 3, 5	2, 4, 3, 1, 5
Which one of the following statements about transport of nutrients in phloem is false? A.A sink may be located anywhere in the plant. B.Solute particles can be actively transported into phloem at the source. C.A sink is that part of the plant where a particular solute is consumed or stored. D.Differences in osmotic concentration at the source and sink cause a hydrostatic pressure gradient to be formed. E.Companion cells control the rate and direction of movement of phloem sap.	E.Companion cells control the rate and direction of movement of phloem sap.
According to the pressure flow hypothesis of phloem transport, A.the formation of starch from sugar in the sink increases the osmotic concentration. B.the combination of a high turgor pressure in the source and transpiration water loss from the sink moves solutes through phloem conduits. C.solute moves from a high concentration in the source to a lower concentration in the sink. D.water is actively transported into the source region of the phloem to create the turgor pressure needed. E.the pressure in the phloem of a root is normally greater than the pressure in the phloem of a leaf.	C.solute moves from a high concentration in the source to a lower concentration in the sink.
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.both the xylem and the endodermis. D.only the endodermis. E.both the xylem and the phloem.	E.both the xylem and the phloem.
Water flows into the source end of a sieve tube because Water flows into the source end of a sieve tube because A.water pressure outside the sieve tube forces in water. B.the companion cell of a sieve tube actively pumps in water. C.sucrose has been transported out of the sieve tube by active transport. D.sucrose has diffused into the sieve tube, making it hypotonic. E.sucrose has been actively transported into the sieve tube, making it hypertonic.	E.sucrose has been actively transported into the sieve tube, making it hypertonic.
In addition to transporting sugar, the phloem also _____. A.transmits electrical signals B.transports viral RNA throughout the plant C.transports plant RNA throughout the plant D.transports proteins throughout the plant E.All of the above	E.All of the above
Plasmodesmata can change in number, and when dilated can provide a passageway for ribosomes. mitochondria. chloroplasts. cytoskeletal components. macromolecules such as RNA and proteins.	macromolecules such as RNA and proteins.
A seed develops from an embryo. an ovule. a pollen grain. an ovary. an ovum.	an ovule.
A fruit is a seed plus its integuments. an enlarged embryo sac. a fused carpel. a mature ovary. a mature ovule.	a mature ovary.
Double fertilization means that A.every egg must receive two sperm to produce an embryo. B.flowers must be pollinated twice to yield fruits and seeds. C.the egg of the embryo sac is diploid. D.every sperm has two nuclei. E.one sperm is needed to fertilize the egg, and a second sperm is needed to fertilize the polar nuclei.	E.one sperm is needed to fertilize the egg, and a second sperm is needed to fertilize the polar nuclei.
"Golden Rice" A.is resistant to various herbicides, making it practical to weed rice fields with those herbicides. B.produces larger, golden grains that increase crop yields. C.is resistant to a virus that commonly attacks rice fields. D.contains daffodil genes that increase vitamin A content. E.includes bacterial genes that produce a toxin that reduces damage from insect pests.	D.contains daffodil genes that increase vitamin A content.
Which statement concerning grafting is correct? A.Stocks come from vines, but scions come from trees. B.Grafting creates new species. C.Stocks and scions must come from unrelated species. D.Stocks and scions refer to twigs of different species. E.Stocks provide root systems for grafting.	E.Stocks provide root systems for grafting.
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 XY/endosperm XXX or embryo XX/endosperm XXY B.embryo XX/endosperm XXX or embryo XY/endosperm XXY C.embryo XX/endosperm XX or embryo XY/endosperm XY D.embryo XX/endosperm XXX or embryo XY/endosperm XYY E.embryo X/endosperm XX or embryo Y/endosperm XY	B.embryo XX/endosperm XXX or embryo XY/endosperm XXY
A small flower with green petals is most likely bird-pollinated. bat-pollinated. bee-pollinated. moth-pollinated. wind-pollinated.	wind-pollinated.
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.small pollen grains can be carried farther by the wind. B.wind-pollinated plants release pollen in the spring, before the plant has stored enough energy to make large pollen grains. C.animal pollinators are more facile at picking up large pollen grains. D.wind-pollinated flowers don’t need large pollen grains because they don’t have to attract animal pollinators. E.wind-pollinated plants, in general, are smaller than animal pollinated plants.	A.small pollen grains can be carried farther by the wind.
The black dots that cover strawberries are actually individual fruits. The fleshy and tasty portion of a strawberry derives from the receptacle of a flower with many separate carpels. Therefore, a strawberry is A.both an aggregrate fruit and an accessory fruit. B.both a multiple fruit and an aggregate fruit. C.a simple fruit with many seeds. D.both a multiple fruit and an accessory fruit. E.both a simple fruit and an aggregate fruit.	A.both an aggregrate fruit and an accessory fruit.
Select the correct statement about double fertilization in the angiosperm life cycle. A.Double fertilization produces a diploid sporophyte and a triploid endosperm. B.Double fertilization results from the fusion of the male and female gametophytes of angiosperms. C.Double fertilization prevents the production of infertile pollen grains.	A.Double fertilization produces a diploid sporophyte and a triploid endosperm.
Which of these represents the male gametophyte generation of an angiosperm? An anther The ovule Cells within a pollen grain	Cells within a pollen grain
Which of these structures is/are produced by fertilization of egg and sperm? A fruit An embryonic sporophyte Endosperm	An embryonic sporophyte
Which of these represents the female gametophyte generation of an angiosperm? An embryo sac An ovule An ovary	An embryo sac
Select the correct statement(s) about angiosperm seeds. Select all that apply. A.The embryo in an angiosperm seed is the offspring of the sporophyte plant. B.All structures in an angiosperm seed are diploid. C.An angiosperm seed contains structures contributed by three generations of plants.	C.An angiosperm seed contains structures contributed by three generations of plants.
What does it mean to say that pigweed is resistant to herbicide? A.Pigweed hosts insects that prey on crop plants, reducing the productivity of farmland where pigweed grows. B.Pigweed prevents the application of herbicide to a field of cotton or soybeans. C.Pigweed now acts as an herbicide, killing crop plants that grow near pigweed plants. D.Pigweed plants thrive despite the application of herbicides intended to kill them.	D.Pigweed plants thrive despite the application of herbicides intended to kill them.
In the past, herbicides were very effective as a pigweed killer, but today _____. A.pigweed is taking over fields of cotton and soybeans B.pigweed is allowed to grow, then pulled by hand to use as a biofuel C.farmers prefer a greener, more natural solution to battle pigweed D.farmers prefer newer, more effective chemical control of pigweed	A.pigweed is taking over fields of cotton and soybeans
The scientists who produced the herbicide warned against overuse, saying that over time, ____. A.resistant weeds would increase in number B.the soil would become contaminated and affect future planting C.crops would start to be affected by the herbicide D.crops would start to become less resistant to insect pests	A.resistant weeds would increase in number
Why is pigweed so difficult to control? Select all that apply. A.the way it spreads like a vine on the ground and is hidden from view B.its thick, woody stem C.the number of inches it grows daily D.the number of seeds it produces	B.its thick, woody stem C.the number of inches it grows daily D.the number of seeds it produces
What effect(s) has the proliferation of herbicide-resistant pigweed had on southern farmers? Select all that apply. A.They can’t plant cotton or soybeans anymore. B.They have to hire laborers to cut and remove the weeds by hand. C.Their large machinery is prone to damage from the pigweed plants. D.They may have to pick their crops by hand.	B.They have to hire laborers to cut and remove the weeds by hand. C.Their large machinery is prone to damage from the pigweed plants. D.They may have to pick their crops by hand.
You open your refrigerator and grab some broccoli for a snack. It has a pungent, sharp smell. What causes this? carbon dioxide ammonia methane sulfur compounds	sulfur compounds
Your aunt lives in Iowa. What is likely the biggest problem she faces when she tries to grow broccoli? The climate is too dry. The climate is too wet. The climate is too hot. The climate is too cold.	The climate is too hot.
While at the grocery store, you notice the broccoli is yellowish. What likely caused this? It was under water stress. It was exposed to a virus. The flowers opened. It was picked too early.	The flowers opened.
Fresh broccoli should have what kind of taste? bitter salty sweet sour	sweet
Cabbage is a very close relative of broccoli. Thus cabbage is what? cruciferous a legume a tuber an aggregate	cruciferous
What is endosperm? A.tissue that develops into a protective seed coat surrounding the embryo B.the female portion of a flowering plant C.via cotyledons, a source of food for the embryo D.the male portion of a flowering plant E.the leaves that are a part of the embryo	C.via cotyledons, a source of food for the embryo
Fruits evolved primarily as structures specialized to _____. provide a source of food to the plant’s embryo disperse seeds provide food for humans protect pollen protect seeds	disperse seeds
Why do fleshy fruits often have seeds with very tough seed coats? A.So the seeds can be dispersed by propulsion B.So the seeds can survive the mechanical forces and conditions in an animal’s gut C.So the seeds can adhere to passing animals D.So the seeds can extend the distance they travel by catching breezes	B.So the seeds can survive the mechanical forces and conditions in an animal’s gut
What characterizes the fruit of seeds that are dispersed by the wind? A.They are large. B.They contain a large amount of sugar. C.They are very fleshy. D.They have structures to extend the distance they travel on the wind.	D.They have structures to extend the distance they travel on the wind.
True or false? Fruits provide food to the developing plant. True False	False
Which part of a flower develops into the seed? Endosperm cell Ovule Pericarp Carpel	Ovule
Which term describes the portion of a peach that can be eaten by humans? Endosperm Pericarp Zygote Seed coat	Pericarp
True or false? The endosperm tissue that nourishes the developing plant has the same nutritional characteristics regardless of the plant species. True False	False
Which part of a plant attracts pollinators? Carpel Petals Sepal Stamen	Petals
Which process involves the transfer of pollen grains from an anther to a stigma? Germination Pollination Fertilization Gametogenesis	Pollination
True or false? The endosperm in a seed develops into the embryo. True False	False
Which term describes the male gametophytes of flowering plants? Microsporocytes Micropyle Pollen grains Megaspores	Pollen grains
Which structure formed by the male gametophyte allows sperm to reach the ovary of a flowering plant? Anther Micropyle Pollen tube Stigma	Pollen tube
How is fertilization in flowering plants different from fertilization in other plant groups? A.One sperm nucleus fuses with the egg to form a diploid zygote, whereas the other sperm nucleus fuses with a polar nucleus to form a diploid cell that forms a nutrient-rich tissue. B.Two sperm nuclei fuse with a polar nucleus to form a diploid zygote. C.One sperm nucleus fuses with the egg to form a diploid zygote. D.One sperm nucleus fuses with the egg to form a diploid zygote, whereas the other sperm nucleus fuses with two polar nuclei to form a cell that develops into endosperm.	D.One sperm nucleus fuses with the egg to form a diploid zygote, whereas the other sperm nucleus fuses with two polar nuclei to form a cell that develops into endosperm.
Which of the following statements about seed formation in a flowering plant is true? A.The swellings that develop into cotyledons are located at the end of the embryo on top of the row of single cells. B.The terminal cell formed from mitosis of the zygote divides to form a row of single cells that eventually forms the embryo. C.Hypocotyls are the seed leaves of the embryonic plant. D.The basal cell formed from mitosis of the zygote divides to form a globular mass that is the route for nutrient transfer to the developing embryo.	A.The swellings that develop into cotyledons are located at the end of the embryo on top of the row of single cells.
Meiosis will produce microspores in the _____. petal ovary anther receptacle sepal	anther
Which association below is correct? A.bisexual flowers … dioecious B.dioecious … separate female and male plants C.unisexual flowers … dioecious D.monoecious … bisexual flowers E.anther … egg production	B.dioecious … separate female and male plants
In angiosperms, each pollen grain produces two sperm. What do these sperm do? A.Each one fertilizes a separate egg cell. B.One fertilizes an egg, and the other combines with two polar nuclei, which develop into stored food cells (endosperm). C.One fertilizes an egg, and the other fertilizes the fruit. D.Both sperm fertilize a single egg cell. E.One fertilizes an egg, and the other is kept in reserve.	B.One fertilizes an egg, and the other combines with two polar nuclei, which develop into stored food cells (endosperm).
The germination of seeds _____. A.depends on imbibition B.occurs after a certain species-specific period of time C.depends on maturation of the embryo D.depends on the growth of the embryo rupturing the seed E.results in the cotyledon being the first structure to emerge from the seed	A.depends on imbibition
Which of the following best describes the ploidy level of a fertilized embryo sac? A.The ploidy level varies among species. B.All cells are polyploid. C.All cells are diploid. D.There are haploid, diploid, and triploid cells. E.All cells are triploid.	D.There are haploid, diploid, and triploid cells.
A flowering plant with a deleterious mutation in microsporogenesis would most likely fail to produce sepals. fail to produce ovules. fail to produce petals. fail to produce anthers. fail to produce pollen.	fail to produce pollen.
A mature, unfertilized ovule in an angiosperm is the result of A.a single mitotic division. B.both meiotic and mitotic divisions. C.differentiation from the suspensor tissues. D.mitosis from the megaspore mother cell. E.a single meiotic division.	B.both meiotic and mitotic divisions.
At the conclusion of meiosis in plants, the end products are always four haploid spores. seeds. eggs. gametes. sperm.	spores.
Which of the following is the correct sequence during the alternation of generations life cycle in a flowering plant? A.sporophyte → mitosis → gametophyte → meiosis → sporophyte B.sporophyte → meiosis → gametophyte → gametes → fertilization → diploid zygote C.haploid gametophyte → gametes → meiosis → fertilization → diploid sporophyte D.sporophyte → spores → meiosis → gametophyte → gametes E.haploid sporophyte → spores → fertilization → diploid gametophyte	B.sporophyte → meiosis → gametophyte → gametes → fertilization → diploid zygote
Which of the following is true in plants? A.Mitosis occurs in gametophytes to produce gametes, meiosis occurs in sporophytes to produce spores, and the gametophyte is within the flower in angiosperms. B.Mitosis occurs in gametophytes to produce gametes. C.Mitosis occurs in gametophytes to produce gametes, and meiosis occurs in sporophytes to produce spores. D.Meiosis occurs in sporophytes to produce spores. E.The gametophyte is within the flower in angiosperms.	A.Mitosis occurs in gametophytes to produce gametes, meiosis occurs in sporophytes to produce spores, and the gametophyte is within the flower in angiosperms.
Which of the following are 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 triploid endosperm within the seed, an ovary that becomes a fruit, and a small (reduced) sporophyte. D.They have a triploid endosperm within the seed and an ovary that becomes a fruit. E.They have a small (reduced) sporophyte.	D.They have a triploid endosperm within the seed and an ovary that becomes a fruit.
The ovary is most often located on/in the sepals. petals. stamen. carpel. receptacle.	carpel.
Microsporangia in flowering plants are located in the stamen. petals. receptacle. sepals. carpel.	stamen.
Which of the following is the correct order of floral organs from the outside to the inside of a complete flower? A.sepals → petals → stamens → carpels B.male gametophyte → female gametophyte → sepals → petals C.sepals → stamens → petals → carpels D.spores → gametes → zygote → embryo E.petals → sepals → stamens → carpels	A.sepals → petals → stamens → carpels
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? pea apple pineapple raspberry peach	apple
All of the following are primary functions of flowers except sexual reproduction. pollen production. meiosis. egg production. photosynthesis.	photosynthesis.
Meiosis occurs within all of the following flower parts except the ovule. anther. megasporangium. ovary. style.	style.
Carpellate flowers develop into fruits. are complete. produce pollen. are perfect. are found only on dioecious plants.	develop into fruits.
Which of the following types of plants are incapable of self-pollination? insect-pollinated complete dioecious monoecious wind-pollinated	dioecious
In flowering plants, pollen is released from the stigma. pollen tube. filament. anther. carpel.	anther.
In the life cycle of an angiosperm, which of the following stages is diploid? A.polar nuclei of the embryo sac B.megaspore C.microsporocyte D.generative nucleus of a pollen grain E.both megaspore and polar nuclei	C.microsporocyte
Which of the following is a correct sequence of processes that takes place when a flowering plant reproduces? A.meiosis → fertilization → ovulation → germination B.growth of pollen tube → pollination → germination fertilization C.meiosis → mitosis → nuclear fusion → pollen D.fertilization → meiosis → nuclear fusion formation of embryo and endosperm E.meiosis → pollination → nuclear fusion formation of embryo and endosperm	E.meiosis → pollination → nuclear fusion formation of embryo and endosperm
Which of the following is incorrectly paired with its life-cycle generation? A.embryo sac-gametophyte B.embryo-sporophyte C.stamen-sporophyte D.pollen-gametophyte E.anther-gametophyte	E.anther-gametophyte
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.microsporocyte → meiosis → microspores → mitosis → two haploid cells per pollen grain C.pollen grain → mitosis → microspores → meiosis → generative cell plus tube cell D.two haploid cells → meiosis → generative cell → tube cell-fertilization → pollen grain E.pollen grain → meiosis → two generative cells → two tube cells per pollen grain	B.microsporocyte → meiosis → microspores → mitosis → two haploid cells per pollen grain
Where and by which process are sperm cells formed in plants? A.meiosis in pollen grains B.mitosis in the micropyle C.mitosis in male gametophyte pollen tube D.meiosis in anthers E.mitosis in the embryo sac	C.mitosis in male gametophyte pollen tube
In which of the following pairs are the two terms equivalent? A.seed-zygote B.endosperm-male gametophyte C.ovule-egg D.microspore-pollen grain E.embryo sac-female gametophyte	E.embryo sac-female gametophyte
Which of the following would be considered a multiple fruit? strawberry corn on the cob apple pineapple raspberry	pineapple
In flowering plants, a mature male gametophyte contains A.a generative cell and a tube cell. B.a haploid nucleus and a diploid pollen wall. C.two haploid microspores. D.two sperm nuclei and one tube cell nucleus. E.two haploid gametes and a diploid pollen grain.	D.two sperm nuclei and one tube cell nucleus.
What is the difference between pollination and fertilization in flowering plants? A.Pollination easily occurs between plants of different species, whereas fertilization is within a species. B.Fertilization precedes pollination. 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.	D.Pollination is the transfer of pollen from an anther to a stigma. Fertilization is the fusion of haploid nuclei.
Genetic incompatibility does not affect the A.attraction of a suitable insect pollinator. B.germination of the pollen on the stigma. C.membrane permeability of cells. D.growth of the pollen tube in the style. E.different individuals of the same species.	A.attraction of a suitable insect pollinator.
What effects would occur in a mutant of Arabidopsis that cannot synthesize GABA within its flowers? A.The length of the style would be increased to the point where the growing pollen tube would be unable to reach the synergids. B.Pollen tube growth would not be directed toward the egg, and fertilization would not occur. C.The pollen grain would not form a pollen tube due to incompatibility with the pollen tube. D.The seeds from the flowers would be unable to break dormancy.	B.Pollen tube growth would not be directed toward the egg, and fertilization would not occur.
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.systems of wind, but not insect, pollination. B.ribonuclease (RNAase) activity in stigma cells. C.pollen grains with very thick walls. D.RNA in the plants. E.carpels that cannot produce eggs by meiosis.	B.ribonuclease (RNAase) activity in stigma cells.
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.Flowers produce fruits from the ovaries. D.The food-storing endosperm is derived from the cell that contains two polar nuclei and one sperm nucleus. E.Pollination is the delivery of pollen to the stigma of a carpel.	B.Female gametophytes develop from megaspores within the anthers.
Where does meiosis occur in a flowering plant? A.megasporocyte B.endosperm C.megasporocyte and microsporocyte D.pollen tube E.microsporocyte	C.megasporocyte and microsporocyte
Which of the following occurs in an angiosperm ovule? A.An antheridium forms from the megasporophyte. B.The nucleus forms a diploid egg. C.A megaspore mother cell undergoes meiosis. D.A pollen tube emerges to accept pollen after pollination. E.The endosperm surrounds the megaspore mother cell.	C.A megaspore mother cell undergoes meiosis.
Three mitotic divisions within the female gametophyte of a flowering plant produces A.a tube nucleus, a generative cell, and a sperm cell. B.three pollen grains. C.two antipodal cells, two polar nuclei, two eggs, and two synergids. D.the triple fusion nucleus. E.three antipodal cells, two polar nuclei, one egg, and two synergids.	E.three antipodal cells, two polar nuclei, one egg, and two synergids.
Recent research has shown that fertilization requires that carpels recognize pollen grains as "self or nonself." For self-incompatibility, the system requires A.that the flowers be incomplete. B.the rejection of nonself cells. C.the rejection of self cells. D.the union of genetically identical sperm and egg cells. E.carpel incompatibility with the egg cells.	C.the rejection of self cells.
Which of the following is an example of sexual reproduction? cuttings apomixis fragmentation stump sprouts fusion of sperm and egg nuclei in an ovule	fusion of sperm and egg nuclei in an ovule
Which of the following is an advantage of asexual reproduction in plants? enhanced seed dispersal no need for a pollinator more robust offspring genetic variation enhanced survival of genetically favorable offspring	enhanced survival of genetically favorable offspring
Self-incompatibility _____. A.works the same way in all plants B.is based on the same mechanism of transplant rejection seen in animals C.does not have potential agricultural applications D.helps maintain genetic variability in a population E.is the rejection of a graft by a plant	D.helps maintain genetic variability in a population
In grafting, the plant that provides the root system is the _____ and the twig is the _____. A.callus … protoplast B.gene donor … gene recipient C.stock … scion D.hypocotyl … epicotyl E.radicle … scion	C.stock … scion
As a flower develops, which transition is most likely to occur? A.The ovule becomes a fruit. B.The vegetative nucleus becomes a sperm nucleus. C.The ovules become ovaries. D.The microspores become pollen grains. E.The petals are retained.	D.The microspores become pollen grains.
The primary function of the integument of an ovule is to A.produce hormones that ensure successful pollination. B.ensure double fertilization. C.protect against animal predation. D.direct development of the endosperm. E.form a seed coat.	E.form a seed coat.
The structure of a mature, functional fruit always includes A.fleshy cells rich in sugars. B.extensive vascular connections to the parent plant. C.one or more seeds. D.subtending bracts to protect against predators. E.brightly colored pigments to attract animal dispersers.	C.one or more seeds.
Which of the following statements argues for an advantage for flowering plants to maintain an extended gametophyte generation? A.It provides sufficient time for the integument to develop into a seed coat. B.It allows for a complex nucleus to develop. C.It allows more time for potential pollination. D.The protection of female gametophytes within ovules keeps them from drying out. E.Sperm with flagella can reach the egg faster.	D.The protection of female gametophytes within ovules keeps them from drying out.
What is typically the result of double fertilization in angiosperms? A.Two embryos develop in every seed. B.The endosperm develops into a diploid nutrient tissue. C.The antipodal cells develop into the seed coat. D.Both a diploid embryo and triploid endosperm are formed. E.A triploid zygote is formed.	D.Both a diploid embryo and triploid endosperm are formed.
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.All of the desirable traits of the cultivar would be passed on to offspring. C.It would be easier to introduce novel genes. D.They would benefit from positive mutations in their DNA. E.They would have a larger potential genome than inbred crops.	B.All of the desirable traits of the cultivar would be passed on to offspring.
Which of the following "vegetables" is botanically a fruit? celery green beans lettuce radish potato	green beans
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. coleoptile; coleorhiza hypocotyl; epicotyl cotyledon; radicle epicotyl; radicle scutellum; coleoptile	coleoptile; coleorhiza
Fruits develop from receptacles. ovules. ovaries. fertilized eggs. microsporangia.	ovaries.
What is the first step in the germination of a seed? fertilization pollination emergence of the radicle imbibition hydrolysis of starch and other food reserves	imbibition
Which of the following is true about vegetative reproduction? A.It can lead to genetically altered forms of the species. B.It involves both meiosis and mitosis to produce haploid and diploid cells. C.It produces clones of the parent plant. D.It produces vegetables and not fruits. E.It involves meiosis only.	C.It produces clones of the parent plant.
Which of the following is a true statement about clonal reproduction in plants? A.Cloning, although achieved in animals, has not been demonstrated in plants. B.Clones of plants do not occur naturally. C.Reproduction of plants by cloning may be either sexual or asexual. D.Viable seeds can result from sexual reproduction only. E.Making cuttings of ornamental plants is a form of fragmentation.	E.Making cuttings of ornamental plants is a form of fragmentation.
Which of the following statements is true for a species that produces seeds by apomixis? A.The embryo of the seed is genetically distinct from the parent plant. B.The seed coat is made of diploid cells derived from the ovule of a flower. C.The scutellum is the primary food storage tissue of the embryo. D.A haploid embryo is contained within the seed. E.The embryo consists of diploid cells derived from fertilization of a haploid egg by a haploid sperm.	B.The seed coat is made of diploid cells derived from the ovule of a flower.
Which of the following could be considered an evolutionary advantage of asexual reproduction in plants? A.increased agricultural productivity in a rapidly changing environment. B.increased success of progeny in a stable environment. C.maintenance and expansion of a large genome. D.increased ability to adapt to a change in the environment. E.production of numerous progeny.	B.increased success of progeny in a stable environment.
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 is the method of test-tube cloning that produces whole plants from callus. C.It can be used to form new plant varieties by combining genomes from two plants. D.It occurs within a callus that is developing in tissue culture. E.It is used to develop gene banks to preserve genetic variability.	C.It can be used to form new plant varieties by combining genomes from two plants.
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? S1S4 S3S4 S2S3 S1S3 Half of all the pollen grains could be successful.	S3S4
Which of the following events suggests there is a change in the egg cell membrane after penetration by a sperm? A.The egg changes color. B.The pollen tube grows away from the egg toward the polar nuclei. C.The Ca2+ concentration increases in the cytoplasm of the egg. D.The egg plasmolyzes. E.Double fertilization occurs.	C.The Ca2+ concentration increases in the cytoplasm of the egg.
The most immediate potential benefits of introducing genetically modified crops include all of the following except A.decreasing the mutation rate of certain genes. B.increasing crop yield. C.creating crops with better potential for biofuel production. D.increasing the amount of land suitable for agriculture. E.creating crops with better nutritional attributes.	A.decreasing the mutation rate of certain genes.
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 A, B and C	D. S2S3
Which of the following is one possible advantage of biofuels vs. oil? A.The CO2 produced by biofuels can be pumped into depleted oil and natural gas fields, effectively sequestering the carbon. B.Biofuels will eliminate the need for gasoline. C.The CO2 produced by biofuels will be absorbed by the crops used to produce them, creating a carbon-neutral cycle. D.They will not produce any greenhouse gas emissions. E.The amount of energy used to produce biofuels will be more than they yield.	C.The CO2 produced by biofuels will be absorbed by the crops used to produce them, creating a carbon-neutral cycle.
Which example below is a concern related to the debate over plant biotechnology? A.increased depletion of soil nutrients B.introduced genes spreading into related wild species and leading to the creation of "superweeds" C.transfer of genes to animal herbivores D.increased reliance on petrochemical fertilizers E.reducing availability of enhanced crops to third-world nations	B.introduced genes spreading into related wild species and leading to the creation of "superweeds"
Biofuels are mainly produced by A.plants that are easy to grow in arid environments. B.the genetic engineering of ethanol-generating genes into plants. C.transgenic crops that have cell walls containing ethylene. D.plants that convert hemicellulose into gasoline. E.the breakdown of cell wall biopolymers into sugars that can be fermented.	E.the breakdown of cell wall biopolymers into sugars that can be fermented.
Which of the following is a scientific concern related to creating genetically modified crops? A.The monetary costs of growing genetically modified plants are significantly greater than traditional breeding techniques. B.Beneficial insects may be harmed by eating pest species. C.Their adaptive advantages would allow them to overpower natural ecosystems. D.Herbicide resistance may spread to weedy species. E.Genetically modified plants are less stable and may revert back to parental genotypes.	D.Herbicide resistance may spread to weedy species.
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.transplant varietal Burgundy plants from France. B.plant seeds obtained from French varietal Burgundy grapes. C.graft varietal Burgundy grape scions onto native (Californian) root stocks. D.cross French Burgundy grapes with native American grapes. E.acquire a tissue culture of varietal Burgundy grapes from France	C.graft varietal Burgundy grape scions onto native (Californian) root stocks.
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 introduction of trangenes into the chloroplast DNA. C.the creation of of transgenic crops that hybridize more easily. D.the creation of crops with flowers that develop normally, but fail to open. E.the creation of transgenic crops with apomictic seeds.	C.the creation of of transgenic crops that hybridize more easily.
The hormone that helps plants respond to drought is ethylene. abscisic acid. gibberellin. auxin. cytokinin.	abscisic acid.
Auxin enhances cell elongation in all of these ways except A.cell wall loosening. B.increased activity of plasma membrane proton pumps. C.acid-induced denaturation of cell wall proteins. D.gene activation. E.increased uptake of solutes.	C.acid-induced denaturation of cell wall proteins.
Charles and Francis Darwin discovered that A.red light is most effective in shoot phototropism. B.auxin is responsible for phototropic curvature. C.auxin can pass through agar. D.light is perceived by the tips of coleoptiles. E.light destroys auxin.	D.light is perceived by the tips of coleoptiles.
How may a plant respond to severe heat stress? A.by creating air tubes for ventilation B.by producing heat-shock proteins, which may protect the plant’s proteins from denaturing C.by reorienting leaves to increase evaporative cooling D.by increasing the proportion of unsaturated fatty acids in cell membranes, reducing their fluidity E.by initiating a systemic acquired resistance response	B.by producing heat-shock proteins, which may protect the plant’s proteins from denaturing
The signaling molecule for flowering might be released earlier than usual in a long-day plant exposed to flashes of A.red light during the day. B.red light during the night. C.red light followed by far-red light during the night. D.far-red light during the day. E.far-red light during the night.	B.red light during the night.
If a long-day plant has a critical night length of 9 hours, which 24-hour cycle would prevent flowering? A.15.5 hours light/8.5 hours dark B.8 hours light/8 hours dark/light flash/8 hours dark C.14 hours light/10 hours dark D.4 hours light/8 hours dark/4 hours light/8 hours dark E.16 hours light/8 hours dark	C.14 hours light/10 hours dark
A plant mutant that shows normal gravitropic bending but does not store starch in its plastids would require a reevaluation of the role of ____________ in gravitropism. light auxin statoliths differential growth calcium	statoliths
Which type of mutant would be most likely to produce a bushier phenotype? A.auxin overproducer B.gibberellin overproducer C.strigolactone overproducer D.cytokinin underproducer E.strigolactone underproducer	E.strigolactone underproducer
When a plant is attacked by a pathogen, it may respond by carrying out a defense that causes cell and tissue death near the infection site, restricting the spread of the pathogen. What is the name of this defense? A.The hypersensitive response B.Physical defense C.Systemic acquired resistance	A.The hypersensitive response
How do plant and animal hormones differ? Select all that apply. A.Unlike animal hormones, plant hormones act only locally. B.Unlike animals hormones, plant hormones do not bind to a specific receptor and trigger responses in target cells and tissues. C.In plants more so than in animals, it is the balance between existing hormones, rather than hormones acting in isolation, that controls growth and development.	C.In plants more so than in animals, it is the balance between existing hormones, rather than hormones acting in isolation, that controls growth and development.
Some plants respond to herbivore damage by releasing volatile compounds. Identify the correct effect(s) of volatiles. Select all that apply. A.Volatiles may poison the attacking herbivore. B.Volatiles may warn nearby plants of the same species, so that they can mount a biochemical defense. C.Volatiles may attract parasitoid wasps to attack an insect herbivore.	B.Volatiles may warn nearby plants of the same species, so that they can mount a biochemical defense. C.Volatiles may attract parasitoid wasps to attack an insect herbivore.
Both plants and animals respond to environmental stimuli. Identify the correct statement(s) about this response. Select all that apply. A.The molecular processes determining how plants and animals perceive environmental changes are equally complex. B.The molecular processes determining how plants and animals perceive environmental changes are often homologous. C,Both plants and animals have physiological cycles called circadian rhythms.	A.The molecular processes determining how plants and animals perceive environmental changes are equally complex. B.The molecular processes determining how plants and animals perceive environmental changes are often homologous. C,Both plants and animals have physiological cycles called circadian rhythms.
Though they are not mobile, plants have effective defenses against biological attack. Identify the correct statement(s) about these defenses. Select all that apply. A.Plants may defend against herbivores by producing compounds that reduce protein function in the herbivore. B.Plants have R proteins that recognize pathogen-derived molecules. C.A plant’s triple response protects it against viral attack.	A.Plants may defend against herbivores by producing compounds that reduce protein function in the herbivore. B.Plants have R proteins that recognize pathogen-derived molecules.
You are an orange farmer in Florida and your trees suffer from citrus greening. What can you do to save them? A.Introduce aphids. B.Nothing – there is currently no cure. C.Cover them in large tents for at least 11 days. D.Spray them with antibiotics.	B.Nothing – there is currently no cure.
You are an entomologist with the USDA. Which of the following insects should you be trying to control in order to slow the spread of citrus greening? dobsonfly mayfly fruit fly psyllid fly	psyllid fly
Walking through a friend’s citrus grove, you see early signs of citrus greening. What do you observe? peeling bark yellowing leaves protruding roots wilting flowers	yellowing leaves
You are a grapefruit farmer. Though you do not live in Florida, your trees have citrus greening. Where do you live? Texas Mississippi New Mexico Louisiana	Texas
You raise baby citrus trees to replace trees affected by citrus greening. Where do you raise them? Outside in sterile soil. Inside greenhouses. In hydroponic gardens. Alongside marigolds.	Inside greenhouses.
What two aspects of climate change appear to be having the most impact on forests? A.Decreasing temperature and more water availability. B.Increasing temperature and less water availability. C.Decreasing temperature and less water availability. D.Increasing temperature and more water availability.	B.Increasing temperature and less water availability.
You are a plant physiologist specializing in how humidity affects water transport in white pines. Which of the following do you study? chloroplasts phloem stolons xylem	xylem
The trees in a forest all have closed stomata. Which of the following is the most likely cause of this? strong winds heavy rains cold temperatures drought	drought
What would happen to a tree in an environment devoid of carbon dioxide? It would die of thirst. Nothing. It would starve. It would grow quite quickly.	It would starve.
For the last few decades, how have most farmers responded to the increasing weed problem? A.By planting different crops. B.By accepting their loss. C.By using different herbicides. D.By switching to mechanical methods of managing weeds.	C.By using different herbicides.
You are a botanist specializing in agricultural weeds. You and your research team find a new weed that looks nearly identical to soybeans. What is this called? crop parasitizing crop mimicry crop predation crop herbivory	crop mimicry
Why have increasing amounts of glyphosate been used since the 1980s? A.Because weeds have not developed a resistance to it. B.Because it is the only chemical that still works on most weeds. C.Because some crops have been genetically modified to be resistant to it. D.Because it is safe to use, even for organic farmers.	C.Because some crops have been genetically modified to be resistant to it.
Which of the following is true? A.The use of herbicides puts a stop to natural selection. B.As the use of herbicides increases, the rate of natural selection in plants declines. C.As the use of herbicides increases, the rate of natural selection in plants also increases. D.There is no correlation between herbicide use and the rate of natural selection in plants.	C.As the use of herbicides increases, the rate of natural selection in plants also increases.
You are part of a team of scientists working for the federal agency responsible for testing the environmental impacts of new genetically modified crops. Who do you work for? A.Food and Drug Administration B.Environmental Protection Agency C.Department of Health and Human Services D.Department of Agriculture	D.Department of Agriculture
Plant hormones act by directly affecting the activities of _____. genes and enzymes membranes genes signal transduction pathways enzymes	signal transduction pathways
The detector of light during de-etiolation (greening) of a tomato plant is (are) auxin. phytochrome. xanthophylls. carotenoids. chlorophyll.	phytochrome.
All of the following can function in signal transduction in plants except receptor proteins. secondary messengers. phytochrome. calcium ions. nonrandom mutations.	nonrandom mutations.
Evergreen trees lose their leaves _____. steadily all year in the summer in the spring every winter every fall	steadily all year
The breakdown of chlorophyll reveals the _____ pigments of a leaf. phycoerythrin xanthophylls anthocyanin carotenoid melanin	carotenoid
The formation of the abscission layer cuts off transport of substances to and from the leaf. As the concentration of sugar trapped within a leaf increases, _____ pigments are produced. carotenoid anthocyanin melanin xanthophyll phycoerythrin	anthocyanin
The protective layer that forms between the abscission layer and the stem consists of _____. A.a layer of green palisade cells B.densely colored cells filled with a waxy layer C.weak, colorless, thin-walled cells D.mycorrhizae E.irregularly shaped cells with very thick, lignified secondary walls	B.densely colored cells filled with a waxy layer
After leaf abscission, growth will resume from the _____. petiole axillary bud abscission layer palisade layer protective layer	axillary bud
_____ trees lose their leaves in preparation for winter. Conifer Fir Deciduous Spruce Pine	Deciduous
Which of the following seedlings will probably bend toward light? A.one whose tip is cut off and topped by a gelatin block containing no plant substances B.one whose tip is cut off C.one whose tip is separated from its base by a gelatin block D.one whose tip is covered with a black plastic cap E.one whose tip is separated from its base by aluminum foil	C.one whose tip is separated from its base by a gelatin block
Which of these plant hormones is not typically considered a growth-promoting substance? abscisic acid cytokinin gibberellin auxin brassinosteroids	abscisic acid
Charles and Francis Darwin concluded from their experiments on phototropism by grass seedlings that the part of the seedling that detects the direction of light is the A.part of the coleoptile that bends during the response. B.base of the coleoptile. C.cotyledon. D.tip of the coleoptile. E.phytochrome in the leaves.	D.tip of the coleoptile.
Which of the following conclusions is supported by the research of both Went and Charles and Francis Darwin on shoot responses to light? A.Agar contains a chemical substance that mimics a plant hormone. B.A chemical substance involved in shoot bending is produced in shoot tips. C.Once shoot tips have been cut, normal growth cannot be induced. D.Light stimulates the synthesis of a plant hormone that responds to light. E.When shoots are exposed to light, a chemical substance migrates toward the light.	B.A chemical substance involved in shoot bending is produced in shoot tips.
A plant seedling bends toward sunlight because A.auxin is found in greatest abundance on the dark side of the stem. B.there is more auxin on the light side of the stem. C.gibberellins produced at the stem tip cause phototropism. D.auxin is destroyed more quickly on the dark side of the stem. E.auxin migrates to the lower part of the stem due to gravity.	A.auxin is found in greatest abundance on the dark side of the stem.
The apical bud of a shoot produces ________, resulting in the inhibition of lateral bud growth. gibberellin cytokinin ethylene auxin abscisic acid	auxin
After some time, the tip of a plant that has been forced into a horizontal position grows upward. This phenomenon is related to A.gibberellin production by stems. B.auxin movement toward the lower side of the stem. C.whether the plant is in the northern or southern hemisphere. D.auxin production in cells receiving red light. E.calcium release from the endoplasmic reticulum of shaded cells.	B.auxin movement toward the lower side of the stem.
The ripening of fruit and the dropping of leaves and fruit are principally controlled by ethylene. carbon dioxide concentration (in air). auxins. cytokinins. indole acetic acid.	ethylene.
The plant hormone involved in aging and ripening of fruit is abscisic acid. auxin. florigen. gibberellin. ethylene.	ethylene.
When growing plants in culture, IAA is used to stimulate cell enlargement. Which plant growth regulator has to now be added to stimulate cell division? cytokinin gibberellin ethylene abscisic acid indoleacetic acid	cytokinin
Why do coleoptiles grow toward light? A.Auxin moves away from the light to the shady side. B.Gibberellins are destroyed by light. C.Auxin is destroyed by light. D.Gibberellins move away from the light to the shady side. E.Auxin synthesis is stimulated in the dark.	A.Auxin moves away from the light to the shady side.
Which of the following statements applies to plant growth regulators? A.They directly control plant protein synthesis and assembly. B.They often have a multiplicity of effects. C.They function independently of other hormones. D.They only act by altering gene expression. E.They affect the division and elongation, but not the differentiation, of cells.	B.They often have a multiplicity of effects.
Plant hormones produce their effects by A.altering the expression of genes. B.altering the expression of genes and modifying the permeability of the plasma membrane. C.modifying the structure of the nuclear envelope membrane. D.modifying the permeability of the plasma membrane. E.modifying the permeability of the plasma membrane and modifying the structure of the nuclear envelope membrane.	B.altering the expression of genes and modifying the permeability of the plasma membrane.
Plant hormones can have different effects at different concentrations. This explains how A.some plants are long-day plants and others are short-day plants. B.auxin can stimulate cell elongation in apical meristems, yet will inhibit the growth of axillary buds. C.genes recognize pathogen genes. D.gibberellin concentration can both induce and break dormancy. E.signal transduction pathways in plants are different from those in animals.	B.auxin can stimulate cell elongation in apical meristems, yet will inhibit the growth of axillary buds.
How does indoleacetic acid affect fruit development? A.by promoting rapid growth of the ovary B.by inhibiting formation of the ovule C.by inducing the formation of brassinosteroids D.by promoting gene expression in cambial tissue E.by preventing pollination	A.by promoting rapid growth of the ovary
Which of the following statements best summarizes the acid growth hypothesis in an actively growing shoot? A.Auxin-activated proton pumps lower the pH of the cell wall, which breaks bonds and makes the walls more flexible B.Auxins activate aquaporins that increase turgor pressure in the cells. C.Auxin stimulates proton pumps in the plasma membrane and tonoplast. D.Auxins and gibberellins are transported to the vacuoles to build up turgor pressure. E.Auxins and gibberellins together act as a lubricant to help stretch cellulose microfibrils	A.Auxin-activated proton pumps lower the pH of the cell wall, which breaks bonds and makes the walls more flexible
According to the acid growth hypothesis, auxin works by A.dissolving sieve plates, permitting more rapid transport of nutrients. B.greatly increasing the rate of deposition of cell wall material. C.dissolving the cell membranes temporarily, permitting cells that were on the verge of dividing to divide more rapidly. D.changing the pH within the cell, which would permit the electron transport chain to operate more efficiently. E.increasing wall plasticity and allowing the affected cell walls to elongate.	E.increasing wall plasticity and allowing the affected cell walls to elongate.
If you were shipping green bananas to a supermarket thousands of miles away, which of the following chemicals would you want to eliminate from the plants’ environment? ethylene cytokinins auxin gibberellic acids CO2	ethylene
Experiments on the positive phototropic response of plants indicate that A.auxin is synthesized in the area where the stem bends. B.auxin is only of secondary importance in the process. C.light destroys auxin. D.auxin can move to the shady side of the stem. E.auxin moves down the plant apoplastically.	D.auxin can move to the shady side of the stem.
Auxins (IAA) in plants are known to affect all of the following processes except inhibition of lateral buds. maintenance of seed dormancy. phototropism of shoots. geotropism of shoots. fruit development.	maintenance of seed dormancy.
If a farmer wanted more loosely packed clusters of grapes, he would most likely spray the immature bunches with gibberellins. auxin. ethylene. abscisic acid. cytokinins.	gibberellins.
Which of the following hormones would be most useful in promoting the rooting of plant cuttings? cytokinins strigolactones indolebutyric acid gibberellins abscisic acid	indolebutyric acid
The aleurone layer is stimulated to release ________ as a result of gibberellin release from the embryo. amylase RNAase carbohydrates cytokinins amino acids	amylase
Which of the following plant growth responses is primarily due to the action of auxins? A.the detection of photoperiod B.the triple response of shoots C.cell elongation D.cell division E.leaf abscission	C.cell elongation
Why are axillary buds often inhibited from growing even though a stem may be actively elongating? A.Axillary buds are high in abscisic acid that prevents elongation. B.Stem cells lack receptors for auxin. C.The cells of axillary buds respond differently to auxin than stem cells. D.Axillary buds are low in gibberellins. E.Stem cells can overcome auxin inhibition with high levels of gibberellins.	C.The cells of axillary buds respond differently to auxin than stem cells.
The application of which of the following hormones would be a logical first choice in an attempt to produce normal growth in mutant dwarf plants? indoleacetic acid cytokinin ethylene gibberellin abscisic acid	gibberellin
For a short-day plant, the _____ is critical in determining if flowering will occur. A.None of these is correct, since short-day plants are also known as day-neutral plants. B.minimum number of hours of darkness C.minimum number of hour of light D.maximum number of hours of light E.maximum number of hours of darkness	B.minimum number of hours of darkness
For a long-day plant, the _____ is critical in determining if flowering will occur. A.None of these is correct, since short-day plants are also known as day-neutral plants. B.maximum number of hours of darkness C.maximum number of hours of light D.minimum number of hours of light E.minimum number of hours of darkness	B.maximum number of hours of darkness
Day-neutral plants flower regardless of _____. A.day length, night length, or photoperiod B.night length C.day length or night length D.day length E.photoperiod	A.day length, night length, or photoperiod
Which of these would inhibit flowering in a short-day plant with a critical night length of 12 hours? A.12 hours of light, 6 hours of dark, a flash of red light, a flash of far-red light, a flash of red light, a flash of far-red light, 6 hours of dark B.12 hours of light, 6 hours of dark, a flash of red light, 6 hours of dark C.All of these regimens would inhibit flowering in a short-day plant with a critical night length of 12 hours. D.12 hours of light followed by 12 hours of dark E.12 hours of light, 6 hours of dark, a flash of red light, a flash of far-red light, 6 hours of dark	B.12 hours of light, 6 hours of dark, a flash of red light, 6 hours of dark
Which of these would stimulate flowering in a long-day plant with a critical night length of 12 hours? A.8 hours of light and 16 hours of dark B.12 hours of light, 6 hours of dark, a flash of red light, a flash of far-red light, a flash of red light, a flash of far-red light, 6 hours of dark C.12 hours of light followed by 12 hours of dark D.12 hours of light, 6 hours of dark, a flash of red light, a flash of far-red light, 6 hours of dark E.12 hours of light, 6 hours of dark, a flash of red light, 6 hours of dark	E.12 hours of light, 6 hours of dark, a flash of red light, 6 hours of dark
The Pr form of the phytochrome pigment has maximum absorption in the _____ part of the spectrum. blue yellow far-red red ultraviolet	red
A biological cycle with a period of about 24 hours is called _____. a biological clock thigmotropism photoperiodism abscission a circadian rhythm	a circadian rhythm
Most plants flower when _____. A.they deplete soil nutrients B.the soil reaches a certain temperature C.the nights are the right length D.a certain number of days have passed since they last flowered E.the days are the right length	C.the nights are the right length
The molecule most involved in the flowering process is _____. FT protein beta-carotene abscisic acid auxin ethylene	FT protein
Seed packets give a recommended planting depth for the enclosed seeds. The most likely reason some seeds are to be covered with only ¼ inch of soil is that the A.seedlings do not have an etiolation response. B.seeds require light to germinate. C.seeds are very sensitive to waterlogging. D.seedlings do not produce a hypocotyl. E.seeds require a higher temperature to germinate	B.seeds require light to germinate.
A short-day plant will flower only when A.nights are longer than a certain critical value. B.days are shorter than nights. C.days and nights are of equal length. D.nights are shorter than a certain critical value. E.days are shorter than a certain critical value.	A.nights are longer than a certain critical value.
A flash of red light followed by a flash of far-red light given during the middle of the night to a short-day plant will likely A.convert florigen to the active form. B.have no effect upon flowering. C.stimulate flowering. D.inhibit flowering. E.cause increased flower production.	B.have no effect upon flowering.
Many plants flower in response to day-length cues. Which of the following statements best summarizes this phenomenon? A.Flowering in day-neutral plants is only influenced by day length if there is an exceptionally warm spring. B.As a rule, short-day plants flower in the summer. C.As a rule, long-day plants flower in the spring or fall. D.Flowering in short-day and long-day plants is controlled by phytochrome. E.Long-day plants flower in response to long days, not short nights	D.Flowering in short-day and long-day plants is controlled by phytochrome.
Which of the following treatments would enhance the level of the Pfr form of phytochrome? A.synthesis of phosphorylating enzymes B.exposure to far-red light C.exposure to red light D.long dark period E.inhibition of protein synthesis	C.exposure to red light
In legumes, it has been shown that "sleep" (nastic) movements are correlated with A.senescence (the aging process in plants). B.ABA-stimulated closing of guard cells caused by loss of K+. C.positive thigmotropisms. D.flowering and fruit development. E.rhythmic opening and closing of K+ channels in motor cell membranes	E.rhythmic opening and closing of K+ channels in motor cell membranes
Which of the following statements is correct with regards to a "circadian rhythm" in plants? A.Once set, it cannot be changed. B.It may have the same signal transduction pathway in all organisms. C.Once set, it is independent of external signals. D.It works independently of photoperiodic responses. E.It can be changed to a longer or shorter period by altering the light quality.	B.It may have the same signal transduction pathway in all organisms.
The biological clock controlling circadian rhythms must ultimately A.depend on environmental cues. B.stabilize on a 24-hour cycle. C.affect gene transcription. D.speed up or slow down with increasing or decreasing temperature. E.do all of the above.	C.affect gene transcription.
Plants often use changes in day length (photoperiod) to trigger events such as dormancy and flowering. It is logical that plants have evolved this mechanism because photoperiod changes A.alter the amount of energy available to the plant. B.are more predictable than air temperature changes. C.are correlated with moisture availability. D.can reset the biological clock. E.are modified by soil temperature changes.	B.are more predictable than air temperature changes.
If the range of a species of plants expands to a higher latitude, which of the following processes is the most likely to be modified by natural selection? circadian rhythm photoperiodic response thigmomorphogenesis phototropic response biological clock	photoperiodic response
What does a short-day plant require in order to flower? A.a day that is longer than a certain length B.a higher ratio of Pr to Pfr C.a burst of red light in the middle of the night D.a night that is longer than a certain length E.a burst of far-red light in the middle of the night	D.a night that is longer than a certain length
If a short-day plant has a critical night length of 15 hours, then which of the following 24-hour cycles will prevent flowering? A.4 hours light/20 hours dark B.2 hours light/20 hours dark/2 hours light C.6 hours light/2 hours dark/light flash/16 hours dark D.8 hours light/8 hours dark/light flash/8 hours dark E.8 hours light/16 hours dark	D.8 hours light/8 hours dark/light flash/8 hours dark
A long-day plant will flower if A.the duration of continuous light is less than a critical length. B.the duration of continuous darkness is less than a critical length. C.the duration of continuous light exceeds a critical length. D.it is kept in continuous far-red light. E.the duration of continuous darkness exceeds a critical length.	B.the duration of continuous darkness is less than a critical length.
Plants that have their flowering inhibited by being exposed to bright lights at night are long-day plants. devoid of phytochrome. short-night plants. day-neutral plants. short-day plants.	short-day plants.
Classic experiments suggested that a floral stimulus, florigen, could move across a graft from an induced plant to a noninduced plant and trigger flowering. Recent evidence using Arabidopsis has recently shown that florigen is probably A.a transcription factor that controls the activation of florigen-specific genes. B.a second messenger that induces Ca++ ions to change membrane potential. C.a membrane signal that travels through the symplast from leaves to buds. D.a protein that is synthesized in leaves, travels to the shoot apical meristems, and initiates flowering. E.a phytochrome molecule that is activated by red light.	D.a protein that is synthesized in leaves, travels to the shoot apical meristems, and initiates flowering.
A short-day plant exposed to nights longer than the minimum for flowering but interrupted by short flashes of light A.might flower depending upon the wavelengths of the light flashes. B.will not be affected and will flower. C.might flower depending upon the duration of the light flash. D.never flower. E.will still flower if ethylene is administered.	A.might flower depending upon the wavelengths of the light flashes.
A long-day plant will flower A.during short days with proper fertilization. B.only under artificial light in the summer. C.regardless of the photoperiod imposed. D.when the night is shorter than a critical value. E.in the late fall.	D.when the night is shorter than a critical value.
In nature, poinsettias bloom in early March. Research has shown that the flowering process is triggered three months before blooming occurs. In order to make poinsettias bloom in December, florists change the length of the light-dark cycle in September. Given the information and clues above, which of the following is a correct statement about poinsettias? A.They require a shorter dark period than is available in September. B.They require a light period longer than some set minimum. C.The dark period can be interrupted without affecting flowering. D.They will flower even if there are brief periods of far-red illumination during the nighttime. E.They are short-day plants.	E.They are short-day plants.
A botanist exposed two groups of the same plant species to two photoperiods-one with 14 hours of light and 10 hours of dark and the other with 10 hours of light and 14 hours of dark. Under the first set of conditions, the plants flowered, but they failed to flower under the second set of conditions. Which of the following conclusions would be consistent with these results? A.The critical day length is 10 hours. B.The critical night length is 14 hours. C.The plants are short-day plants. D.The plants flower in the late spring. E.The plants can convert phytochrome to florigen.	D.The plants flower in the late spring.
What is the physical basis of the phototropic response? Cell transport. Cell elongation. Photosynthesis. Cell shortening.	Cell elongation.
True or false? Auxin is asymmetrically distributed in shoots because the auxin on the side of the plant facing the source of light is destroyed. True False	False
Where does the majority of stem growth in a plant occur? A.Axillary buds. B.Both the apical meristem and lateral branches. C.Apical meristem. D.Lateral branches	C.Apical meristem.
Which of the following statements about hormones is true? A.Hormones are small inorganic molecules. B.Hormones are produced at the sites where they are needed. C.Hormones are produced only in plants. D.Hormones can function at very low concentrations.	D.Hormones can function at very low concentrations.
Which term describes the direction of auxin transport in a plant? Circular. Polar. Bidirectional. Multidirectional.	Polar.
How does auxin produce gravitropism in a plant that is placed on its side? A.Auxin accumulates on the lower surface of the root and stimulates elongation of cells in that region. B.Auxin accumulates on the side of the leaf opposite the sunlight and stimulates elongation of cells in that region. C.Auxin accumulates on the side of the leaf opposite the sunlight and inhibits elongation of cells in that region. D.Auxin accumulates on the lower surface of the root and inhibits elongation of cells in that region.	D.Auxin accumulates on the lower surface of the root and inhibits elongation of cells in that region.
How does auxin produce phototropism? A.Auxin accumulates in cells on the side of the plant opposite the source of light and stimulates their elongation. B.Auxin accumulates in cells on the side of the plant facing the source of light and causes them to shorten. C.Auxin accumulates in cells on the side of the plant opposite the source of light and causes them to shorten. D.Auxin accumulates in cells on the side of the plant facing the source of light and stimulates their elongation.	A.Auxin accumulates in cells on the side of the plant opposite the source of light and stimulates their elongation.
Thigmotropism is a movement in response to _____. light chemicals temperature touch gravity	touch
Which one of the following is a response in plants to a water deficit? A.inhibiting root growth B.increasing the synthesis and release of auxin C.reduction in the rate of transpiration D.inhibiting the abscission of older leaves E.guttation	C.reduction in the rate of transpiration
What do the results of research on gravitropic responses of roots and stems show? A.Light is required for the gravitropic response. B.The effect of a plant hormone can depend on the tissue. C.Different tissues have the same response to auxin. Some responses of plants require no hormones at all. D.Cytokinin can only function in the presence of auxin.	B.The effect of a plant hormone can depend on the tissue.
Vines in tropical rain forests must grow toward large trees before being able to grow toward the sun. To reach a large tree, the most useful kind of growth movement for a tropical vine presumably would be the opposite of positive phototropism. positive thigmotropism. positive gravitropism. circadian rhythms. sleep movements.	positive phototropism.
A botanist discovers a plant that lacks the ability to form starch grains in root cells, yet the roots still grow downward. This evidence refutes the long-standing hypothesis that A.starch accumulation triggers the negative phototropic response of roots. B.starch and downward movement are necessary for thigmotropism. C.starch is converted to auxin, which causes the downward bending in roots. D.starch grains block the acid growth response in roots. E.falling statoliths trigger gravitropism.	E.falling statoliths trigger gravitropism.
You are part of a desert plant research team trying to discover crops that will be productive in arid climates. You discover a plant that produces a hormone under water-deficit conditions that triggers a suite of drought responses. Most likely the hormone is GA. IAA. ABA. 2, 4-D. salicylic acid.	ABA.
Most scientists agree that global warming is underway; thus, it is important to know how plants respond to heat stress. Which of the following would be a useful line of inquiry to try and improve plant response and survival to heat stress? A.increased production of heat-shock proteins B.the opening of stomata to increase evaporational heat loss C.the production of heat-stable carbohydrates D.protoplast fusion experiments with xerophytic plants E.all of the above	A.increased production of heat-shock proteins
In extremely cold regions, woody species may survive freezing temperatures by A.decreasing the numbers of phospholipids in cell membranes. B.emptying water from the vacuoles to prevent freezing. C.producing canavanine as a natural antifreeze. D.decreasing the fluidity of all cellular membranes. E.increasing cytoplasmic levels of specific solute concentrations, such as sugars.	E.increasing cytoplasmic levels of specific solute concentrations, such as sugars.
The initial response of the root cells of a tomato plant watered with seawater would be to A.rapidly expand until the cells burst. B.begin to plasmolyze as water is lost. C.actively absorb salts from the seawater. D.rapidly produce organic solutes in the cytoplasm. E.actively transport water from the cytoplasm into the vacuole.	B.begin to plasmolyze as water is lost.
Which of the following best explains both the growth of a vine up the trunk of a tree as well as the directional growth of a houseplant toward a window? tropism response acclimation morphological response taxic movement nastic movement	tropism response
The rapid leaf movements resulting from a response to touch (thigmotropism) primarily involve rapid growth response. aquaporins. nervous tissue. potassium channels. stress proteins.	potassium channels.
Which organism does not cause disease in plants? Virus. Bacteria. Herbivore. Fungus.	Herbivore.
Which structure does not protect stems and leaves from damage by herbivores? Spines. Trichomes. Thorns. Stomata.	Stomata.
True or false? Plants do not produce many defenses against pathogens unless they are threatened because defensive structures and compounds require much energy and materials to produce and maintain. True False	True
What is the initial localized response of a resistant plant to pathogen invasion? Plant death. Hypersensitive response. Systemic acquired resistance. Systemin production.	Hypersensitive response.
Which compound is not used in the localized response to pathogen invasion? Phytoalexins. Salicylic acid. Proteinase inhibitors. Nitric oxide.	Salicylic acid.
Which of the following statements about systemic acquired resistance (SAR) in plants is false? A.Salicylic acid is the only compound involved in SAR signaling. B.Hormones produced by an attacked leaf carry a signal to the rest of the plant. C.A suite of genes called the pathogenesis-related loci is expressed in response to a signal from an attacked leaf. D.SAR results in the production of protective compounds distant from the site of initial infection.	A.Salicylic acid is the only compound involved in SAR signaling.
How does a plant defend against herbivores? A.The plant produces molecules that stimulate the herbivore’s digestive enzymes. B.The hormone systemin is produced at the site of injury and signals the plant to produce proteinase inhibitors. C.Plant cells produce salicylic acid to warn the rest of the plant about the attack. D.Plant cells at the site of attack are killed to starve the herbivore of nutrients.	B.The hormone systemin is produced at the site of injury and signals the plant to produce proteinase inhibitors.
Strains of pathogens that mildly harm, but do not kill, the host plant are termed _____. salicylic virulent avirulent jasmonic herbivores	avirulent
In order for a plant to initiate chemical responses to herbivory, A.the plant must be directly attacked by an herbivore. B.gene-for-gene recognition must occur. C.volatile "signal" compounds must be perceived. D.phytoalexins must be released. E.it must be past a certain developmental age.	C.volatile "signal" compounds must be perceived.
The transduction pathway that activates systemic acquired resistance in plants is initially signaled by Pfr phytochrome. salicylic acid. abscisic acid. red, but not far-red, light. antisense RNA.	salicylic acid.
Which of the following would only be activated or upregulated after a plant has already been infected by a pathogen? salicylic acid brassinosteroids molecular chaperones phytochrome stress proteins	salicylic acid
A plant will recognize a pathogenic invader A.when the pathogen has an R gene complementary to the plant’s antivirulence (Avr) gene. B.only if the pathogen and the plant have the same R genes. C.if it has many specific plant disease resistance (R) genes. D.when the pathogen secretes Avr protein. E.if it has the specific R gene that corresponds to the pathogen molecule encoded by an Avr gene.	E.if it has the specific R gene that corresponds to the pathogen molecule encoded by an Avr gene.
What is the probable role of salicylic acid in the defense responses of plants? A.to close stomata, thus preventing the entry of pathogens B.to sacrifice infected tissues by hydrolyzing cells C.to destroy pathogens directly D.to activate systemic acquired resistance of plants E.to activate heat-shock proteins	D.to activate systemic acquired resistance of plants
When an arborist prunes a limb off a valuable tree, he or she usually paints the cut surface. The primary purpose of the paint is to A.minimize water loss by evaporation from the cut surface. B.induce the production of phytoalexins. C.improve the appearance of the cut surface. D.stimulate growth of the cork cambium to "heal" the wound. E.block entry of pathogens through the wound.	E.block entry of pathogens through the wound.
In cases where plants exhibit generalized defense responses in organs distant from the infection site, this is termed A.systemic acquired resistance. B.hyperactive responses. C.pleiotropy. D.hyperplasia. E.general systemic response.	A.systemic acquired resistance.
Which of the following is the most likely plant response to an attack by herbivores? A.leaf abscission to prevent further loss B.production of chemical compounds for defense or to attract predators C.production of physical defenses, such as thorns D.production of thicker bark and cuticle to make it more difficult to eat E.early flowering to try and reproduce before being eaten	B.production of chemical compounds for defense or to attract predators
Plant hormonal regulation differs from animal hormonal regulation in that A.plants do not exhibit feedback mechanisms like animals. B.there are no dedicated hormone-producing organs in plants as there are in animals. C.all production of hormones is local in plants with little long-distance transport. D.only animal hormone concentrations are developmentally regulated. E.only animal hormones may have either external or internal receptors.	B.there are no dedicated hormone-producing organs in plants as there are in animals.

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