Question 1

When plants exhibit generalized defense responses in organs distant from the infection site, this is termed

Accepted Answer

A)   a hyperactive response.
B)   systemic acquired resistance.
C)   pleiotropy.
D)   hyperplasia.E) C) and D)
F) A) and B)

Question 2

The apical bud of a shoot produces ________, resulting in the inhibition of lateral bud growth.

Accepted Answer

A)   abscisic acid
B)   ethylene
C)   cytokinin
D)   auxinE) A) and B)
F) None of the above D

Question 3

A short-day plant will flower only when

Accepted Answer

A)   days are shorter than nights.
B)   days are shorter than a certain critical value.
C)   nights are shorter than a certain critical value.
D)   nights are longer than a certain critical value.E) A) and B)
F) A) and C)

Question 4

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?

Accepted Answer

A)   CO₂
B)   cytokinins
C)   ethylene
D)   auxinE) B) and C)
F) A) and B) C

Question 5

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 is consistent with these results?

Accepted Answer

A)   The critical night length is 14 hours.
B)   The plants are short-day plants.
C)   The critical day length is 10 hours.
D)   The plants flower in the late spring.E) None of the above
F) C) and D)

Question 6

In extremely cold regions, woody species may survive freezing temperatures by

Accepted Answer

A)   emptying water from the vacuoles to prevent freezing.
B)   decreasing the numbers of phospholipids in cell membranes.
C)   decreasing the fluidity of all cellular membranes.
D)   increasing cytoplasmic levels of specific solute concentrations, such as sugars.E) A) and D)
F) B) and D)

Question 7

Plant hormonal regulation differs from animal hormonal regulation in that

Accepted Answer

A)   there are no dedicated hormone-producing organs in plants as there are in animals.
B)   all production of hormones is local in plants with little long-distance transport.
C)   plants do not exhibit feedback mechanisms like animals.
D)   only animal hormone concentrations are developmentally regulated.E) None of the above
F) B) and D)

Question 8

After some time, the tip of a plant that has been forced into a horizontal position grows upward. This phenomenon is related to

Accepted Answer

A)   calcium release from the endoplasmic reticulum of shaded cells.
B)   whether the plant is in the northern or southern hemisphere.
C)   auxin production in cells receiving red light.
D)   auxin movement toward the lower side of the stem.E) None of the above
F) A) and D)

Question 9

Which of the following hormones would be most useful in promoting the rooting of plant cuttings?

Accepted Answer

A)   strigolactones
B)   cytokinins
C)   gibberellins
D)   indolebutyric acidE) A) and C)
F) B) and C)

Question 10

Which of the following is the most likely plant response to an attack by herbivores?

Accepted Answer

A)   leaf abscission to prevent further loss
B)   early flowering to try to reproduce before being eaten
C)   production of chemical compounds for defense or to attract predators
D)   production of physical defenses, such as thornsE) All of the above
F) None of the above

Question 11

Why do coleoptiles grow toward light?

Accepted Answer

A)   Auxin is destroyed by light.
B)   Gibberellins are destroyed by light.
C)   Auxin synthesis is stimulated in the dark.
D)   Auxin moves away from the light to the shady side.E) None of the above
F) B) and D)

Question 12

Which of the following best explains both the growth of a vine up the trunk of a tree and the directional growth of a houseplant toward a window?

Accepted Answer

A)   nastic movement
B)   taxic movement
C)   tropism response
D)   morphological responseE) A) and D)
F) All of the above

Question 13

A short-day plant exposed to nights longer than the minimum for flowering but interrupted by short flashes of light

Accepted Answer

A)   will never flower.
B)   might flower depending upon the duration of the light flash.
C)   will not be affected and will flower.
D)   might flower depending upon the wavelengths of the light flashes.E) A) and D)
F) A) and C)

Question 14

A plant mutant that showed normal gravitropic bending but did not store starch in its plastids would require a reevaluation of the role of ________ in gravitropism.

Accepted Answer

A)   auxin
B)   statoliths
C)   light
D)   differential growthE) A) and D)
F) B) and D) B

Question 15

The rapid leaf movements resulting from a response to touch (thigmotropism)  primarily involve

Accepted Answer

A)   rapid growth response.
B)   potassium channels.
C)   nervous tissue.
D)   aquaporins.E) A) and D)
F) A) and C)

Question 16

Why are axillary buds often inhibited from growing even though a stem may be actively elongating?

Accepted Answer

A)   The cells of axillary buds respond differently to auxin than stem cells.
B)   Axillary buds are high in abscisic acid that prevents elongation.
C)   Axillary buds are low in gibberellins.
D)   Stem cells lack receptors for auxin.E) A) and B)
F) A) and C)

Question 17

A plant will recognize a pathogenic invader

Accepted Answer

A)   if it has many specific plant disease resistance (R)  genes.
B)   when the pathogen has an R gene complementary to the plant's antivirulence (Avr)  gene.
C)   only if the pathogen and the plant have the same R genes.
D)   if it has the specific R gene that corresponds to the pathogen molecule encoded by an Avr gene.E) None of the above
F) All of the above

Question 18

Charles and Francis Darwin discovered that

Accepted Answer

A)   red light is most effective in shoot phototropism.
B)   auxin can pass through agar.
C)   light destroys auxin.
D)   light is perceived by the tips of coleoptiles.E) A) and C)
F) B) and C)

Question 19

Which of the following plant responses is primarily due to the action of gibberellins?

Accepted Answer

A)   cell division
B)   sex determination
C)   inhibits growth
D)   promotes ripening of many types of fruitE) All of the above
F) A) and D)

Question 20

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

Accepted Answer

A)   seedlings do not produce a hypocotyl.
B)   seedlings do not have an etiolation response.
C)   seeds require light to germinate.
D)   seeds require a higher temperature to germinate.E) A) and D)
F) B) and D)

Exam 31: Plant Responses to Internal and External Signals

When plants exhibit generalized defense responses in organs distant from the infection site, this is termed

Correct Answer
verified

The apical bud of a shoot produces ________, resulting in the inhibition of lateral bud growth.

Correct Answer
verified
D

A short-day plant will flower only when

Correct Answer
verified

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?

Correct Answer
verified
C

Correct Answer
verified

In extremely cold regions, woody species may survive freezing temperatures by

Correct Answer
verified

Plant hormonal regulation differs from animal hormonal regulation in that

Correct Answer
verified

After some time, the tip of a plant that has been forced into a horizontal position grows upward. This phenomenon is related to

Correct Answer
verified

Which of the following hormones would be most useful in promoting the rooting of plant cuttings?

Correct Answer
verified

Which of the following is the most likely plant response to an attack by herbivores?

Correct Answer
verified

Why do coleoptiles grow toward light?

Correct Answer
verified

Which of the following best explains both the growth of a vine up the trunk of a tree and the directional growth of a houseplant toward a window?

Correct Answer
verified

A short-day plant exposed to nights longer than the minimum for flowering but interrupted by short flashes of light

Correct Answer
verified

A plant mutant that showed normal gravitropic bending but did not store starch in its plastids would require a reevaluation of the role of ________ in gravitropism.

Correct Answer
verified
B

The rapid leaf movements resulting from a response to touch (thigmotropism) primarily involve

Correct Answer
verified

Why are axillary buds often inhibited from growing even though a stem may be actively elongating?

Correct Answer
verified

A plant will recognize a pathogenic invader

Correct Answer
verified

Charles and Francis Darwin discovered that

Correct Answer
verified

Which of the following plant responses is primarily due to the action of gibberellins?

Correct Answer
verified

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

Correct Answer
verified

Exam 31: Plant Responses to Internal and External Signals

When plants exhibit generalized defense responses in organs distant from the infection site, this is termed

Correct AnswerverifiedShow Answer

The apical bud of a shoot produces ________, resulting in the inhibition of lateral bud growth.

Correct AnswerverifiedD

A short-day plant will flower only when

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedC

Correct AnswerverifiedShow Answer

In extremely cold regions, woody species may survive freezing temperatures by

Correct AnswerverifiedShow Answer

Plant hormonal regulation differs from animal hormonal regulation in that

Correct AnswerverifiedShow Answer

After some time, the tip of a plant that has been forced into a horizontal position grows upward. This phenomenon is related to

Correct AnswerverifiedShow Answer

Which of the following hormones would be most useful in promoting the rooting of plant cuttings?

Correct AnswerverifiedShow Answer

Which of the following is the most likely plant response to an attack by herbivores?

Correct AnswerverifiedShow Answer

Why do coleoptiles grow toward light?

Correct AnswerverifiedShow Answer

Which of the following best explains both the growth of a vine up the trunk of a tree and the directional growth of a houseplant toward a window?

Correct AnswerverifiedShow Answer

A short-day plant exposed to nights longer than the minimum for flowering but interrupted by short flashes of light

Correct AnswerverifiedShow Answer

A plant mutant that showed normal gravitropic bending but did not store starch in its plastids would require a reevaluation of the role of ________ in gravitropism.

Correct AnswerverifiedB

The rapid leaf movements resulting from a response to touch (thigmotropism) primarily involve

Correct AnswerverifiedShow Answer

Why are axillary buds often inhibited from growing even though a stem may be actively elongating?

Correct AnswerverifiedShow Answer

A plant will recognize a pathogenic invader

Correct AnswerverifiedShow Answer

Charles and Francis Darwin discovered that

Correct AnswerverifiedShow Answer

Which of the following plant responses is primarily due to the action of gibberellins?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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D

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C

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B

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