Deck 39: Plant Nutrition and Soils

Question 1

Certain plants have been genetically modified to secrete citrate,which helps

A)make the phosphate in soils more soluble.
B)plants make necessary micronutrients.
C)reveal mineral deficiencies in a plant.
D)make hydroponic growth possible.
E)plants add metals to the soil in which they are growing.

Answer 1

A

Question 2

The ongoing growth of a plant does not require

A)light input.
B)nutrient input.
C)oxygen for photosynthesis.
D)CO₂.
E)water absorption.

Answer 2

C

Question 3

The Nod factor is an important component of

A)the formation of the digestive enzymes of carnivorous plants.
B)legume-bacterial interactions.
C)inorganic fertilizers.
D)the Calvin Cycle.
E)photorespiration.

Answer 3

B

Question 4

Plants can remove harmful chemicals from the soil by the process of

A)glandular secretion by leaves.
B)CO₂ activation.
C)phytoremediation.
D)fertilization.
E)root nodule formation.

Question 5

Plants need ammonia (NH₃)to

A)build amino acids.
B)build fatty acids.
C)build micronutrients.
D)fix nitrogen.
E)deter herbivores.

Question 6

In topsoil,which of these components usually represents the greatest volume?

A)mineral particles of varying size
B)living organisms
C)humus
D)roots
E)air and water

Question 7

Which of the following is not a natural process of plants that can be used by humans to remove toxins from soils?

A)secretion of a substance from the roots that breaks down the toxic chemical
B)"storage" of a toxic chemical in plant tissues,which are then removed from the site
C)root pressure pushes toxins from deep in the soil towards the surface
D)physiological breakdown of the chemical into harmless products
E)transport of toxins absorbed by the roots into the shoots,where they can be collected more easily

Question 8

A primary advantage of using organic fertilizers compared to inorganic chemical fertilizers is that

A)less organic fertilizer is needed than chemical fertilizers.
B)only organic fertilizers contain micronutrients.
C)organic fertilizers release nutrients more slowly.
D)chemical fertilizers are not soluble in water.
E)chemical fertilizers break down very slowly.

Question 9

Heavy metals in contaminated soils can be taken up by hyper-accumulating plants.Lead and cadmium taken up this way are often accumulated in the plants'

A)rhizomes.
B)trichomes.
C)stomates.
D)sclerenchyma.
E)root nodules.

Question 10

A deficiency in a plant micronutrient

A)is less serious than a deficiency in a macronutrient.
B)makes that plant susceptible to herbivores.
C)can have a severe effect on plant growth.
D)results in no visible symptoms.
E)has no impact on the agriculture of a region.

Question 11

Trichlorotheylene (TCE)is toxic to humans because it

A)depletes nitrogen from soils.
B)is carcinogenic.
C)contains heavy metals.
D)prevents CO2 production by plants.
E)causes a decrease in the yield of crop plants.

Question 12

Inserting a cloned gene for a certain plasma membrane transporter into crop plants could lead to

A)the ability of a plant to produce its own micronutrients.
B)extra uptake of minerals that would fortify the crop for human consumption.
C)the evolution of nodule-formation on the crop plant.
D)elevated CO₂ levels in the atmosphere.
E)plants taking up enough minerals that they no longer need to photosynthesizE.

Question 13

Which of these is not a characteristic of soil?

A)It is made up of one or more kinds of minerals.
B)It is the product of weathering of rocks.
C)The mineral and organic soil particles have mostly negatively-charged surfaces.
D)Negatively charged ions predominate in the soil solution.
E)Positive ions are readily available to plants.

Question 14

Although symbiotic relationships between nitrogen-fixing bacteria and plants are rare,many plants have symbiotic relationships with

A)other plants.
B)nematode worms in the soil.
C)filamentous algae.
D)mycorrhizal fungi in the soil.
E)soil insects.

Question 15

Carnivorous plants evolved because which of the following nutrients is often extremely limited in their habitats?

A)carbon
B)CO₂
C)O₂
D)nitrogen
E)iron

Question 16

Which of the following statements about plant macronutrients is not true?

A)They approach or exceed 1% of a healthy plant's dry weight.
B)They reduce the need for CO₂ during photosynthesis.
C)A deficiency in any one can have severe effects on a plant's growth.
D)They can have important implications for human nutrition.
E)The ability of the plants to uptake minerals is affected by soil pH.

Question 17

The effects of elevated atmospheric CO₂ concentrations

A)have the potential to alter the nutritional status of plants.
B)have the potential to allow herbivores to eat less plant matter.
C)have no effect on nutrient levels found in plant leaves.
D)allow the plant to use O₂ more efficiently in photosynthesis.
E)cause an increase in Rubisco production.

Question 18

Which of the following statements about plants grown in hydroponic culture is true?

A)They no longer need to transport water through their xylem.
B)They cannot be used for commercial purposes.
C)They rarely get enough micronutrients.
D)They are unable to photosynthesize.
E)They are suspended with their roots in a nutrient solution.

Question 19

Natural communities recycle nutrients,but cultivated communities often require an input of mineral nutrients due to losses through

A)erosion.
B)humus.
C)nitrogen fixation.
D)crop rotation.
E)iron accumulation.

Question 20

Which of the following combinations of plant nutrients make up about 94% of a plant's dry weight?

A)nitrogen,phosphorus,and potassium
B)carbon,iron,and phosphorus
C)calcium,chlorine,and manganese
D)zinc,oxygen,and boron
E)carbon,oxygen,and hydrogen

Question 21

Which of the following is not a plant micronutrient?

A)iron
B)phosphorus
C)chlorine
D)copper
E)manganese

Question 22

Why is it beneficial to plants that soil particles have negatively-charged surfaces?

A)It helps maintain the water potential of the soil.
B)They attract positively-charged ions and prevent them from being washed deep into the soil.
C)Negatively-charged ions are pushed towards the roots.
D)Toxic metals are trapped and kept away from the plants.
E)They capture negatively-charged ions.

Question 23

Insectivorous plants such as the Venus flytrap,pitcher plant,and bladderworts often grow in

A)loams.
B)sandy soil.
C)clay soil.
D)marshes.
E)acidic soils.

Question 24

During the initiation of nitrogen-fixation nodules,the Rhizobium bacteria release what type of molecules to signal the host plant?

A)sugars
B)proteins
C)transcription factors
D)flavonoids
E)Nod factors

Question 25

Splitting the triple bonds of a N₂ molecule with the nitrogenase enzyme requires ______ ATPs.

A)2
B)4
C)8
D)16
E)32

Question 26

Which of the following does not increase the level of nutrients available to crop plants?

A)adding humus to the soil
B)crop rotation
C)plowing crop residues under
D)applying herbicides
E)applying chemical fertilizers

Question 27

During the initiation of nitrogen-fixation nodules,the host plant releases what type of molecules that signal the Rhizobium bacteria?

A)sugars
B)proteins
C)transcription factors
D)flavonoids
E)Nod factors

Question 28

Which of the following is not a plant macronutrient?

A)boron
B)potassium
C)phosphorus
D)nitrogen
E)sulfur

Question 29

If increased CO₂ concentrations result in plant tissue that is less nutritious,which of these is not a potential consequence for insect herbivores?

A)They must eat more tissue.
B)Their development may be slowed.
C)They grow fatter because their diet has more carbohydrates.
D)They use up more energy trying to eat for fooD.
E)Their reproductive cycles may be disrupted because their rate of growth changes.

Question 30

Humus often enhances the water and nutrient-retaining properties of topsoil.Which of the following might increase the humus content of a soil the most?

A)nitrogen fertilizers
B)organic fertilizers
C)phosphorous fertilizers
D)potassium fertilizers
E)inorganic fertilizers

Question 31

When legumes with nitrogen-fixation nodules are given chemical fertilizers with high nitrogen concentrations,they abandon support of the nodules and end the symbiosis.Why?

A)The mineral nutrients inhibit nitrogenase activity.
B)Nitrogen gas is no longer available in the soil.
C)The nitrogen-fixation process is very expensive for the plant.
D)The dissolved chemical nutrients are toxic to Rhizobium bacteria.
E)Dissolved nitrogen uncurls the root hairs,releasing the nodulE.

Question 32

The habitats most favorable for the growth of legumes in symbiosis with nitrogen-fixing bacteria are

A)bogs.
B)prairies.
C)hilly slopes.
D)grasslands.
E)nitrogen-poor soils.

Question 33

Which of the following is most limiting for plant growth,especially in relation to the plant's carbon uptake?

A)phosphorous
B)potassium
C)nitrogen
D)calcium
E)magnesium

Question 34

Mycorrhizae are especially effective in helping plant roots uptake

A)nitrogen.
B)phosphorus.
C)potassium.
D)iron.
E)magnesium.

Question 35

What makes a mineral element essential for plant growth?

A)It is part of typical chemical fertilizers.
B)It can only be found in organic fertilizers.
C)If it is missing,the plant cannot grow or reproduce normally.
D)As its concentration increases,the plant grows more.
E)It contributes to the solute potential of the plant.

Question 36

During the initiation of nitrogen-fixation nodules,how do the Rhizobium bacteria enter into the cortex of the root?

A)through the plasmadesmata of the root hairs
B)via the apoplastic pathway
C)proton pumps
D)a membrane tube called an infection thread
E)by repeated cell divisions

Question 37

The most important mineral nutrients added to soils in fertilizers are

A)nitrogen,phosphorous,and potassium.
B)calcium and nitrogen.
C)magnesium,phosphorus,and iron.
D)sulfur.
E)calcium carbonatE.

Question 38

Which of these insectivorous plants does not use an active trapping mechanism?

A)pitcher plants
B)Venus flytraps
C)sundews
D)the aquatic waterwheel
E)bladderworts

Question 39

If the parasitic dodder plant (Cuscuta spp. )lacks chlorophyll,what types of nutrients is it most likely extracting from its host?

A)proteins
B)mineral nutrients
C)lipids
D)carbohydrates
E)nucleic acids

Question 40

Why do nitrogen-fixation nodules contain large amounts of leghemoglobin?

A)It helps transport oxygen to the bacteriA.
B)The nitrogenase enzyme interacts with the iron in the leghemoglobin.
C)The leghemoglobin helps break the triple bond of N₂.
D)It stimulates the Nod factors.
E)It prevents oxygen from inhibiting the nitrogenase enzymE.

Question 41

In several studies of plant responses to elevated CO₂ concentrations in the atmosphere,scientists often found that the stimulation of growth gradually diminished because

A)more photorespiration occurred.
B)C₃ plants were replaced with C₄ plants.
C)the soil did not contain sufficient nitrogen and other nutrients to support the enhanced growth.
D)the plants could not store the extra biomass.
E)weedy plants took over the experimental plots.

Question 42

Choose the letter of the best match from the following:
A.nitrogen
B.calcium
C.potassium
D.phosphorus
E.magnesium
Contained in amino acids,proteins,nucleic acids,chlorophyll.

Question 43

Choose the letter of the best match from the following:
A.nitrogen
B.calcium
C.potassium
D.phosphorus
E.magnesium
Component of ADP,ATP,nucleic acids,and several coenzymes.

Question 44

Choose the letter of the best match from the following:
A.nitrogen
B.calcium
C.potassium
D.phosphorus
E.magnesium
Required for protein synthesis and operation of stomata.

Question 45

Choose the letter of the best match from the following:
A.nitrogen
B.calcium
C.potassium
D.phosphorus
E.magnesium
Component of chlorophyll,activates many enzymes,divalent cation.

Question 46

In acidic soils or in habitats subjected to prolonged acid rain,what element is often released from rocks that is toxic to many plants?

A)iron
B)chlorine
C)molybdenum
D)selenium
E)aluminum

Question 47

Which of these is not affected strongly by elevated growth temperatures in plants?

A)photosynthesis
B)respiration
C)photorespiration
D)transpiration
E)carbon : nitrogen ratios in the plant tissues

Question 48

Choose the letter of the best match from the following:
A.nitrogen
B.calcium
C.potassium
D.phosphorus
E.magnesium
Component of cell walls,involved in maintenance of membrane structure.

Question 49

A typical root pumps out H⁺ to maintain a strong membrane potential of about

A)-12 V.
B)120 V.
C)60 Hz.
D)-160 mV.
E)pH 5.0.

Question 50

In magnesium-deficient plants the older leaves show more severe symptoms of chlorosis than younger leaves.What is the best explanation?

A)There is more time for the symptoms to develop in older leaves.
B)Chlorophyll is transported from the older leaves to the younger leaves.
C)Magnesium is more soluble in younger leaves.
D)Scarce magnesium is removed from older leaves and translocated to support younger,more active leaves.
E)Older leaves need less chlorophyll.

Question 51

Inside nitrogen-fixing nodules,one N₂ molecule is converted into two

A)N.
B)NO.
C)NO₂.
D)NO₃.
E)NH₃.

Question 52

Which of the following is not part of a nitrogen-fixing nodule?

A)root hairs
B)cortex cells
C)bacteroids
D)vascular tissue
E)lateral meristem

Question 53

Which of these is not considered a potentially dangerous heavy metal contaminant in soil?

A)cadmium
B)iron
C)arsenic
D)lead
E)zinc