Question 1

Constitutive defenses differ from inducible defenses in that the:

Accepted Answer

A)  genetic program to produce the former is always on, while the genetic program to produce the latter must be switched on by the sensing of herbivore presence.
B)  latter is more efficient when the target herbivore may be absent for much of the growth of the plant.
C)  former is always less efficient than the latter because inducible defenses are only turned on when needed.
D)  former are more likely to confer broad forms of resistance to multiple herbivores, while the latter are more likely to be specific to particular herbivores.

Question 2

Would a plant that is exposed first to a virus and then to an herbivore be expected to have more than, less than, or the same amount of damage from herbivory as a plant exposed to just the herbivore and why?

Accepted Answer

A)  more, because the threats are sufficiently different that the plant cannot coordinate an optimal defense against each threat at the same time
B)  less, because the systematic required resistance triggered by the virus means the herbivores will encounter plants with heightened general defenses
C)  the same, due to a trade-off between viral and herbivore defenses
D)  the same, because viral defense and herbivore defense are nonoverlapping

Question 3

The high silica content in grasses and the thick enamel layer on horse teeth are examples of:

Accepted Answer

A)  a trade-off between growth and defense.
B)  the "escape and radiate" hypothesis.
C)  symbiotic co-evolution.
D)  an evolutionary arms race. D

Question 4

Which of the following plant responses targets a SPECIFIC organism (i.e., would not be considered a "general" response") ?

Accepted Answer

A)  a basal immune response
B)  R proteins recognizing AVR proteins
C)  a systemic acquired resistance response
D)  siRNA

Question 5

What are possible mechanisms of action for defensive compounds produced by plants?

Accepted Answer

A)  to prevent premature molting in insects
B)  to prevent proteins from being digested
C)  to interfere with cell division
D)  to interfere with an herbivore's nervous system

Question 6

Would you expect a plant growing at high density (with many close neighbors)  to have higher or lower allocation to defense than one growing at low density?

Accepted Answer

A)  Allocation to defense would be similar in both environments because it depends on soil type, not plant density.
B)  Allocation to defense would be higher under high plant densities because losing any leaves to herbivores might lead to overtopping by neighbors.
C)  Allocation to defense would be higher for plants at low density because such plants would not have to allocate resources to growing tall in order to avoid overshading.

Question 7

The presence of thorns is an example of _____ defenses.

Accepted Answer

A)  constitutive
B)  induced
C)  chemical
D)  active

Question 8

Which types of plants would you expect to experience a greater conflict between defense and growth, plants that rely more on inducible defenses or plants that rely more on constitutive defenses?

Accepted Answer

A)  plants that rely more on inducible defenses
B)  plants that rely more on constitutive defenses
C)  None of the answer options is correct. B

Question 9

Bitter cassava is often preferred as a crop over sweet cassava because it produces higher yields (more pounds of cassava per hectare planted)  in the presence of herbivores. Which of the following statements poses a hypothetical link (relationship)  between the ability to make chemical deterrents and higher yields?

Accepted Answer

A)  Plants produce chemicals to deter herbivores. Bitter cassava stores toxic compounds in its tissues. Bitter cassava should incur less damage, and therefore have higher yields.
B)  Plants produce chemicals to deter herbivores. Bitter cassava stores toxic compounds in its roots. Because they are below ground, the roots are not eaten and the presence of toxic compounds does not contribute to higher yields.
C)  Plants produce chemicals to deter herbivores. Bitter cassava expends energy producing toxic compounds. The more toxic compounds a plant produces, the lower its yields.
D)  Plants produce chemicals to deter herbivores. Bitter cassava requires additional nitrogen to make these compounds. The additional nitrogen that is used reduces the amount of nitrogen available for plant growth and decreases yields.

Question 10

Consider this figure from your text.  How do you think the daily increase in leaf area of the clay-origin and sand-origin species, when growing in the unprotected clay and sandy habitats, would change in response to a large increase in far-red light?

Accepted Answer

A)  The daily increase in leaf area would be lower for the clay species in both habitats, but the increase in far-red light would have no effect on the sandy-origin species in either habitat.
B)  The daily increase in leaf area would be higher for both species in the clay habitat, but lower for both in the unprotected habitat.
C)  The daily increase in leaf area would be lower for both species in both habitats.
D)  The increase in far-red light would have no effect in the clay habitat, but the clay-origin species would have even greater losses of leaf area in the sandy habitat

Question 11

Which of the following statements is TRUE regarding the systemic acquired resistance (SAR)  response in plants?

Accepted Answer

A)  It is pathogen-specific.
B)  It relies on salicylic acid.
C)  It is only effective against biotrophic pathogens.
D)  Strong SAR responses are associated with tissue necrosis.

Question 12

You are studying inducible defenses against herbivory in a plant by pretreating some of the plants with a small amount of simulated herbivory damage before exposing them to herbivores. You notice that in one of your experimental lineages the mature leaves, but not the developing leaves or meristematic tissues, receive just as much damage from insects whether they receive the pretreatment or not. You hypothesize that, in this lineage, _____ has been down-regulated.

Accepted Answer

A)  the production of jasmonic acid
B)  constitutive defense
C)  the ability to respond to jasmonic acid
D)  methylation of jasmonic acid

Question 13

Which of the following is TRUE of protein-based plant chemical defenses?

Accepted Answer

A)  Plants and animals use the same 20 amino acids to construct proteins, but some plants have additional amino acids.
B)  Plants use the additional amino acids in their proteins, but animals that ingest them cannot.
C)  Insect herbivores that consume nonprotein amino acids grow more quickly and live longer.
D)  Plants can produce protease inhibitors, which bind to the active site of enzymes that break down proteins and enhance their activity.
E)  Insects that feed on plants with protease inhibitors have increased growth rates.

Question 14

Some herbivores are known as _____, feeding on a wide variety of plant species.

Accepted Answer

A)  specialists
B)  omnivores
C)  generalists
D)  autotrophs
E)  carnivores

Question 15

A farmer has adopted a new program of integrative pest management. What will this program entail for the farmer and his crops?

Accepted Answer

A)  The farmer will assess which pests are consuming his crops.
B)  The farmer will use industrial pesticides as a first line of defense.
C)  The farmer will introduce natural predators for the pests.
D)  The farmer will use industrial pesticides as a last line of defense.

Question 16

The genes encoding the Bt toxins that protect some crops from herbivory originally evolved in:

Accepted Answer

A)  the wild relatives of maize.
B)  fungal symbionts of plants.
C)  bacterial symbionts of plants.
D)  soil-dwelling bacteria. D

Question 17

The first line of plant defense against pathogen infection is/are the:

Accepted Answer

A)  cuticle.
B)  plasmodesmata.
C)  stomata.
D)  pathogens.
E)  cell walls.

Question 18

_____ pathogens obtain resources from living cells, whereas _____ pathogens kill cells before colonizing them.

Accepted Answer

A)  Biotrophic; necrotrophic
B)  Necrotrophic; biotrophic
C)  All bacterial; all fungi
D)  All fungi; all bacterial

Question 19

Over 380,000 species of angiosperms exist on Earth. Which of the following factors contributed to this diversity of flowering plants?

Accepted Answer

A)  pollination by different insects
B)  infections by different bacteria
C)  predation by different herbivores
D)  infections by different fungi

Question 20

Which of the following does NOT occur as a result of infection by Rhizobium radiobacter?

Accepted Answer

A)  Other tumors will form farther away from the original gall if the tumor metastasizes and moves through the phloem.
B)  DNA isolated from the tumor will be from both the plant and Rhizobium.
C)  Carbon compounds that are not synthesized elsewhere in the plant will be synthesized in the tumor.
D)  The cells of the crown gall are all descended from the original infected cells.

Exam 32: Plant Defense: Keeping the World Green

Constitutive defenses differ from inducible defenses in that the:

Correct Answer
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Would a plant that is exposed first to a virus and then to an herbivore be expected to have more than, less than, or the same amount of damage from herbivory as a plant exposed to just the herbivore and why?

Correct Answer
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The high silica content in grasses and the thick enamel layer on horse teeth are examples of:

Correct Answer
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D

Which of the following plant responses targets a SPECIFIC organism (i.e., would not be considered a "general" response") ?

Correct Answer
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What are possible mechanisms of action for defensive compounds produced by plants?

Correct Answer
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Would you expect a plant growing at high density (with many close neighbors) to have higher or lower allocation to defense than one growing at low density?

Correct Answer
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The presence of thorns is an example of _____ defenses.

Correct Answer
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Which types of plants would you expect to experience a greater conflict between defense and growth, plants that rely more on inducible defenses or plants that rely more on constitutive defenses?

Correct Answer
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B

Correct Answer
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Consider this figure from your text. How do you think the daily increase in leaf area of the clay-origin and sand-origin species, when growing in the unprotected clay and sandy habitats, would change in response to a large increase in far-red light?

Correct Answer
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Which of the following statements is TRUE regarding the systemic acquired resistance (SAR) response in plants?

Correct Answer
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Correct Answer
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Which of the following is TRUE of protein-based plant chemical defenses?

Correct Answer
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Some herbivores are known as _____, feeding on a wide variety of plant species.

Correct Answer
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A farmer has adopted a new program of integrative pest management. What will this program entail for the farmer and his crops?

Correct Answer
verified

The genes encoding the Bt toxins that protect some crops from herbivory originally evolved in:

Correct Answer
verified
D

The first line of plant defense against pathogen infection is/are the:

Correct Answer
verified

_ pathogens obtain resources from living cells, whereas _ pathogens kill cells before colonizing them.

Correct Answer
verified

Over 380,000 species of angiosperms exist on Earth. Which of the following factors contributed to this diversity of flowering plants?

Correct Answer
verified

Which of the following does NOT occur as a result of infection by Rhizobium radiobacter?

Correct Answer
verified

Exam 32: Plant Defense: Keeping the World Green

Constitutive defenses differ from inducible defenses in that the:

Correct AnswerverifiedShow Answer

Would a plant that is exposed first to a virus and then to an herbivore be expected to have more than, less than, or the same amount of damage from herbivory as a plant exposed to just the herbivore and why?

Correct AnswerverifiedShow Answer

The high silica content in grasses and the thick enamel layer on horse teeth are examples of:

Correct AnswerverifiedD

Which of the following plant responses targets a SPECIFIC organism (i.e., would not be considered a "general" response") ?

Correct AnswerverifiedShow Answer

What are possible mechanisms of action for defensive compounds produced by plants?

Correct AnswerverifiedShow Answer

Would you expect a plant growing at high density (with many close neighbors) to have higher or lower allocation to defense than one growing at low density?

Correct AnswerverifiedShow Answer

The presence of thorns is an example of _____ defenses.

Correct AnswerverifiedShow Answer

Which types of plants would you expect to experience a greater conflict between defense and growth, plants that rely more on inducible defenses or plants that rely more on constitutive defenses?

Correct AnswerverifiedB

Correct AnswerverifiedShow Answer

Consider this figure from your text. How do you think the daily increase in leaf area of the clay-origin and sand-origin species, when growing in the unprotected clay and sandy habitats, would change in response to a large increase in far-red light?

Correct AnswerverifiedShow Answer

Which of the following statements is TRUE regarding the systemic acquired resistance (SAR) response in plants?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which of the following is TRUE of protein-based plant chemical defenses?

Correct AnswerverifiedShow Answer

Some herbivores are known as _____, feeding on a wide variety of plant species.

Correct AnswerverifiedShow Answer

A farmer has adopted a new program of integrative pest management. What will this program entail for the farmer and his crops?

Correct AnswerverifiedShow Answer

The genes encoding the Bt toxins that protect some crops from herbivory originally evolved in:

Correct AnswerverifiedD

The first line of plant defense against pathogen infection is/are the:

Correct AnswerverifiedShow Answer

_____ pathogens obtain resources from living cells, whereas _____ pathogens kill cells before colonizing them.

Correct AnswerverifiedShow Answer

Over 380,000 species of angiosperms exist on Earth. Which of the following factors contributed to this diversity of flowering plants?

Correct AnswerverifiedShow Answer

Which of the following does NOT occur as a result of infection by Rhizobium radiobacter?

Correct AnswerverifiedShow Answer

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D

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B

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D

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_ pathogens obtain resources from living cells, whereas _ pathogens kill cells before colonizing them.

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