Deck 38: Plant Nutrition and Soils

Question 1

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

Answer 1

C

Question 2

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

A)carbon
B)CO₂
C)O₂
D)nitrogen

Answer 2

D

Question 3

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.

Answer 3

A

Question 4

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

Question 5

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.

Question 6

A primary advantage of using integrated nutrient management 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.

Question 7

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.

Question 8

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.

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.

Question 10

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)using proton pumps
D)through a membrane tube called an infection thread

Question 11

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.

Question 12

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.

Question 13

The Nod factor is an important component of

A)the formation of the digestive enzymes of carnivorous plants.
B)legume-bacterial interactions.
C)mycorrhizal-terrestrial plant interactions.
D)the Calvin Cycle.

Question 14

Inserting a cloned gene for a 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.

Question 15

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

A)glandular secretion by leaves.
B)CO₂ activation.
C)phytoremediation.
D)fertilization.

Question 16

Which of the following is required by plants in the smallest quantity?

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

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.

Question 18

During the initiation of nitrogen-fixation nodules, a host plant with genetic mutations releases altered forms of flavonoids.What is the likely consequence of this?

A)Infection threads will grow in the wrong direction.
B)More nodules will form than necessary.
C)The bacteria will not produce any Nod factors.
D)Nodules will be misshapen.

Question 19

Trichloroethylene (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.

Question 20

A deficiency of ammonia would inhibit the production of which of the following molecules?

A)proline and alanine
B)starch
C)short chain fatty acids
D)glucose and fructose

Question 21

A soil sample with a OH^- concentration of 10^-9 M may also have high levels of aluminum.

Question 22

A magnesium deficiency would impact the light-independent reactions but not the light-dependent reaction of photosynthesis.

Question 23

Which of these is considered a potentially dangerous heavy metal contaminant in soil?

A)cadmium
B)iron
C)copper
D)molybdenum

Question 24

In magnesium-deficient plants the older leaves show more severe symptoms of chlorosis which is a yellowing of the leaves 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.

Question 25

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

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

Question 26

Plants that sequester heavy metals utilize pressure-flow where they move toxins from the source (soil) to a sink (such as the leaves).

Question 27

A parasitic plant without chlorophyll is likely to lack leaves.

Question 28

Blocking the proton pumps in a root would result in a more negative membrane potential and an increase in K⁺ uptake.

Question 29

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.

Question 30

A plant with 80 available ATP could produce 10 molecules of NH₃.

Question 31

A plant cell with 64 available ATP molecules could split how many N₂ molecules with the assistance of nitrogenase?

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

Question 32

When plants are grown in hydroponic culture, their roots are suspended in an aerated solution.Why is the solution aerated? Check all that apply._____ Both the light-dependent and the light-independent reactions of photosynthesis require oxygen.__X__ Oxygen is necessary for the root cells to produce ATP.__X__ Without oxygen, membrane transport in the roots would be impaired._____ A lack of oxygen would cause the water potential within the roots to decrease.__X__ Without oxygen, the xylem would stop flowing.

Question 33

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.

Question 34

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.

Question 35

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 plant can conserve valuable energy sources by terminating the symbiotic relationship.
D)The dissolved chemical nutrients are toxic to Rhizobium bacteria.

Question 36

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.

Question 37

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.

Question 38

As global temperatures increase, evidence suggests that ribulose 1, 5-biphosphate carboxylase/oxygenase (rubisco) is likely to denature and photosynthesis rates will decrease.

Question 39

Mycorrhizae are especially effective in helping plant roots uptake

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

Question 40

Saline soils have a higher water potential than plant roots.

Question 41

In lab, you are studying the long term effects of elevated carbon dioxide levels on photosynthesis in C3 and C4 plants.The C3 and C4 plants are growing in separate closed chambers.Both chambers are constantly given elevated but equal amounts of carbon dioixde.Which of the following are likely results of this experiment? Check all that apply._____ There would be a decrease in O₂ levels in both chambers.__X__ There would be an increase in O₂ levels in both containers._____ Both the C3 and the C4 plants would show equal gains in biomass._____ The C4 plants would gain more biomass relative to the C3 plants.__X__ The C3 plants would gain more biomass relative to the C4 plants.

Question 42

Most parasitic plants like other land plants have mycorrhizal symbionts.