Question 1

The following questions refer to the description below.
Plants are not able to move away from predators,so they have evolved chemical methods to protect themselves.Biologists have observed that caterpillars munching on a leaf can be attacked by certain species of wasps.These wasps lay their eggs inside the caterpillar's body,and when the eggs hatch,the larvae feed on its host from the inside.
-How do wasps find plants with caterpillars? You design an experiment in which one group of plants is torn/shredded by human fingers,another group of plants has leaves cut off with plant shears,a third group of plants has leaves stapled,and the fourth group of plants has leaves eaten by caterpillars.After several days of observation,only the plant with caterpillars has attracted wasps.The most likely conclusion is that

Accepted Answer

A)  plants take longer to release specific chemicals to attract wasps if leaves are damaged by means other than herbivory.
B)  plants "recruit" predatory wasps only when they are being eaten by a herbivore.
C)  plants damaged by shredding, cutting, or stapling produce chemical signals that likely repel wasps.
D)  wasps can detect the caterpillars by sight.
E)  wasps find the caterpillars by chance.F) A) and E)
G) B) and E)

Question 2

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)  stress proteins.F) A) and C)
G) A) and D)

Question 3

The houseplants in a windowless room with only fluorescent lights begin to grow tall and leggy.Which of the following treatments would promote more normal growth?

Accepted Answer

A)  Leave the lights on at night as well as during the day.
B)  Add additional fluorescent tubes to increase the light output.
C)  Add some incandescent bulbs to increase the amount of red light.
D)  Set a timer to turn on the lights for 5 minutes during the night.
E)  Turn off the lights for 5 minutes during the day.F) D) and E)
G) A) and B)

Question 4

Plant hormones produce their effects by
I.altering the expression of genes.
II.modifying the permeability of the plasma membrane.
III.modifying the structure of the nuclear envelope membrane.

Accepted Answer

A)  only I
B)  only II
C)  only III
D)  only I and IIE) A) and B)
F) A) and C)

Question 5

Which of the following hormones would never be found in high concentrations in a dormant overwintering flower bud?

Accepted Answer

A)  auxin
B)  cytokinins
C)  abscisic acid
D)  ethylene
E)  gibberellinsF) B) and E)
G) A) and C)

Question 6

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)  days and nights are of equal length.F) A) and D)
G) A) and E)

Question 7

In order for a plant to initiate chemical responses to herbivory

Accepted Answer

A)  the plant must be directly attacked by an herbivore.
B)  volatile "signal" compounds must be perceived.
C)  gene-for-gene recognition must occur.
D)  phytoalexins must be released.
E)  it must be past a certain developmental age.F) All of the above
G) A) and B)

Question 8

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

Accepted Answer

A)  oligosaccharins
B)  abscisic acid
C)  cytokinins
D)  gibberellins
E)  auxinsF) B) and D)
G) C) and D)

Question 9

In lettuce seeds,blue light initiates germination.If you measured hormone levels within the seed,which hormone would be produced upon exposure to blue light?

Accepted Answer

A)  gibberellin
B)  ethylene
C)  abscisic acid
D)  cytokininsE) A) and D)
F) All of the above

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 and reproduce before being eaten
C)  production of chemical compounds for defence or to attract predators
D)  production of physical defences, such as thorns
E)  production of thicker bark and cuticle to make it more difficult to eatF) A) and B)
G) A) and E)

Question 11

We know from the experiments of the past that plants bend toward light because

Accepted Answer

A)  they need sunlight energy for photosynthesis.
B)  the sun stimulates stem growth.
C)  cell expansion is greater on the dark side of the stem.
D)  auxin is inactive on the dark side of the stem.
E)  phytochrome stimulates florigen production.F) None of the above
G) A) and E)

Question 12

A population of plants experiences several years of severe drought.Much of the population dies due to lack of water,but a few individuals survive.You set out to discover the physiological basis for their adaptation to such an extreme environmental change.You hypothesize that the survivors have the ability to synthesize higher levels of ________ than their siblings do.

Accepted Answer

A)  auxin
B)  gibberellin
C)  cytokinin
D)  abscisic acidE) B) and C)
F) None of the above

Question 13

A long-day plant will flower

Accepted Answer

A)  in the late fall.
B)  when the night is shorter than a critical value.
C)  only under artificial light in the summer.
D)  during short days with proper fertilization.
E)  regardless of the photoperiod imposed.F) B) and C)
G) A) and D)

Question 14

Seed packets give a recommended planting depth for the enclosed seeds.The most likely reason some seeds are to be covered with only 1/4 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)  seeds are very sensitive to waterlogging.F) B) and D)
G) B) and C)

Question 15

Auxin triggers the acidification of cell walls,which results in rapid growth,but also stimulates sustained,long-term cell elongation.What best explains how auxin brings about this dual growth response?

Accepted Answer

A)  Auxin binds to different receptors in different cells.
B)  Different concentrations of auxin have different effects.
C)  Auxin causes second messengers to activate both proton pumps on the plasma membrane and certain genes within the same cells.
D)  The dual effects are due to two different types of auxins that are produced by different genes.
E)  Other antagonistic hormones modify auxin's effects.F) All of the above
G) D) and E)

Question 16

Why might animal hormones function differently than plant hormones?

Accepted Answer

A)  Animal receptors are very different than plant receptors.
B)  Plant cells have a cell wall that blocks passage of many hormones.
C)  Plants must have more precise timing of their reproductive activities.
D)  Plants are much more variable in their morphology and development than animals.
E)  Animal receptors are more hydrophobic than plant receptors.F) A) and E)
G) C) and E)

Question 17

Which plant hormones would likely be found in high amounts in a sprouting vegetative stem?

Accepted Answer

A)  auxins, gibberellins, cytokinins
B)  gibberellins, brassinosteroids, cytokinins
C)  auxins, abscisic acid, ethylene
D)  auxins, phytochrome, brassinosteroids
E)  gibberellins, cytokinins, abscisic acidF) A) and D)
G) A) and E)

Question 18

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)  when the pathogen secretes Avr protein.F) B) and C)
G) A) and E)

Question 19

Generalized defense responses in organs distant from the infection site are called

Accepted Answer

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

Question 20

Evidence for phototropism due to the asymmetric distribution of auxin moving down the stem

Accepted Answer

A)  was first demonstrated in the coleoptiles of monocots.
B)  has been found in all monocots and most eudicots.
C)  has been shown to involve only IAA stimulation of cell elongation on the dark side of the stem.
D)  can be demonstrated with unilateral red light, but not blue light.
E)  is now thought by most plant scientists not to involve the shoot tip.F) C) and D)
G) D) and E)

Exam 39: Plant Responses to Internal and External Signals

A long-day plant will flower

Correct Answer
verified

Auxin triggers the acidification of cell walls,which results in rapid growth,but also stimulates sustained,long-term cell elongation.What best explains how auxin brings about this dual growth response?

Correct Answer
verified

Why might animal hormones function differently than plant hormones?

Correct Answer
verified

Correct Answer
verified

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

Correct Answer
verified

In lettuce seeds,blue light initiates germination.If you measured hormone levels within the seed,which hormone would be produced upon exposure to blue light?

Correct Answer
verified

Evidence for phototropism due to the asymmetric distribution of auxin moving down the stem

Correct Answer
verified

The houseplants in a windowless room with only fluorescent lights begin to grow tall and leggy.Which of the following treatments would promote more normal growth?

Correct Answer
verified

Which of the following hormones would never be found in high concentrations in a dormant overwintering flower bud?

Correct Answer
verified

Plant hormones produce their effects by I.altering the expression of genes. II.modifying the permeability of the plasma membrane. III.modifying the structure of the nuclear envelope membrane.

Correct Answer
verified

We know from the experiments of the past that plants bend toward light because

Correct Answer
verified

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

Correct Answer
verified

In order for a plant to initiate chemical responses to herbivory

Correct Answer
verified

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 1/4 inch of soil is that the

Correct Answer
verified

A short-day plant will flower only when

Correct Answer
verified

Which plant hormones would likely be found in high amounts in a sprouting vegetative stem?

Correct Answer
verified

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

Correct Answer
verified

Generalized defense responses in organs distant from the infection site are called

Correct Answer
verified

A plant will recognize a pathogenic invader

Correct Answer
verified

Exam 39: Plant Responses to Internal and External Signals

A long-day plant will flower

Correct AnswerverifiedShow Answer

Auxin triggers the acidification of cell walls,which results in rapid growth,but also stimulates sustained,long-term cell elongation.What best explains how auxin brings about this dual growth response?

Correct AnswerverifiedShow Answer

Why might animal hormones function differently than plant hormones?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

In lettuce seeds,blue light initiates germination.If you measured hormone levels within the seed,which hormone would be produced upon exposure to blue light?

Correct AnswerverifiedShow Answer

Evidence for phototropism due to the asymmetric distribution of auxin moving down the stem

Correct AnswerverifiedShow Answer

The houseplants in a windowless room with only fluorescent lights begin to grow tall and leggy.Which of the following treatments would promote more normal growth?

Correct AnswerverifiedShow Answer

Which of the following hormones would never be found in high concentrations in a dormant overwintering flower bud?

Correct AnswerverifiedShow Answer

Plant hormones produce their effects by I.altering the expression of genes. II.modifying the permeability of the plasma membrane. III.modifying the structure of the nuclear envelope membrane.

Correct AnswerverifiedShow Answer

We know from the experiments of the past that plants bend toward light because

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

In order for a plant to initiate chemical responses to herbivory

Correct AnswerverifiedShow Answer

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 1/4 inch of soil is that the

Correct AnswerverifiedShow Answer

A short-day plant will flower only when

Correct AnswerverifiedShow Answer

Which plant hormones would likely be found in high amounts in a sprouting vegetative stem?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Generalized defense responses in organs distant from the infection site are called

Correct AnswerverifiedShow Answer

A plant will recognize a pathogenic invader

Correct AnswerverifiedShow Answer

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