Question 1

Which of the following statements about plant toxins against herbivores is false?

Accepted Answer

A)  The toxin may be kept in a membrane-bound structure to keep it from harming the plant.
B)  The toxin may not be toxic unless it is metabolized in the intestine of a herbivore.
C)  The toxin may have also have a bad taste.
D)  Even a little bit of the toxin will be deadly.
E)  Some toxins can over stimulate particular physiological processes.F) C) and D)
G) All of the above

Question 2

Nonnative plant invaders,such as the alfalfa plant bug,are extremely invasive and hard to control because

Accepted Answer

A)  they arrive in new locations where natural predators are not present.
B)  they tap into the xylem of a plant while seeking carbohydrates.
C)  they cause the plants' axillary buds to grow out.
D)  their populations evolve faster than the plants they attack.
E)  cause the plants' stomates to become unevenly distributed within the epidermis.F) A) and B)
G) A) and C)

Question 3

How does systemin cause the activation of the wound response in tomato plants?

Accepted Answer

A)  It binds directly to jasmonic acid.
B)  It directly signals gene expression.
C)  It induces the production of tannins.
D)  It induces a jasmonic acid signaling pathway in certain cells.
E)  It triggers genes that are able to signal the plant that mechanical injury has occurred.F) None of the above
G) B) and E)

Question 4

How does jasmonic acid contribute to the activation of the wound response in tomato plants?

Accepted Answer

A)  It moves through the phloem of the plant until it reaches the wound site.
B)  It produces a polypeptide that binds with membrane lipids.
C)  It binds to enzymes in the gut of the predator.
D)  It increases the energy available for the plants to fight the predator.
E)  It signals gene expression,leading to the production of a proteinase inhibitor.F) A) and E)
G) A) and B)

Question 5

Viruses travel through animals mainly by lysing cells and then spreading to other cells.Plant cells are not easily lysed.If a pathogen enters a plant cell and does not initiate a hypersensitive response,what is the most likely way the virus would spread to other plant cells?

Accepted Answer

A)  Through the chloroplasts
B)  Directly through the cell wall
C)  Through the central vacuole
D)  Through the plasmodesmata
E)  Through transport vesiclesF) B) and E)
G) A) and B)

Question 6

Which of the following steps is not one of the phases of a fungal invasion of a plant?

Accepted Answer

A)  Windblown fungal spores land on plant leaves.
B)  Hyphae grow through cell walls and press against the cell membrane.
C)  Fungal DNA is replicated by the plant cells.
D)  Hyphae differentiate into specialized structures called haustoria.
E)  A fungal spore germinates and forms an adhesion pad that allows it to stick to a plant's leaf.F) B) and D)
G) B) and E)

Question 7

The steps in the pathogen-specific response do not include

Accepted Answer

A)  responding to the pathogen.
B)  development of antibodies.
C)  recognizing the pathogen.
D)  triggering the hypersensitive response.
E)  the pathogen releases distinctive proteins.F) B) and C)
G) B) and E)

Question 8

Parasitic fungi will usually attack a plant through stomata on the root surface.

Accepted Answer

A) True 
 B)False

Question 9

Systemic response occurs when plants exhibit generalized defense responses in organs distant from the wound.

Accepted Answer

A) True 
 B)False

Question 10

Which of the following is a false statement about plant secondary metabolites?

Accepted Answer

A)  Some can be used to treat human diseases.
B)  Some can be poisonous to humans.
C)  The activity of certain medicines is due to secondary metabolites.
D)  Some of them can cross the placenta during pregnancy.
E)  They are too unpredictable to use in pharmaceutical research.F) A) and D)
G) A) and C)

Question 11

Which of the following methods do fungi use in order to penetrate the initial layer of a plant's defenses?

Accepted Answer

A)  mechanical bridging
B)  sharp mouthparts
C)  entry through stomates
D)  secretion of phospholipids to dissolve the cuticleE) A) and D)
F) B) and C)

Question 12

The activation of proteinase inhibitor genes occurs

Accepted Answer

A)  in the cytoplasm of the affected cells.
B)  on the plasma membrane of the affected cells.
C)  in the nucleus of the affected cells.
D)  before the systemin moves through the phloem of the plant.
E)  in anticipation of a physical wound to the plant.F) B) and C)
G) None of the above

Question 13

Cyanogenic glycosides,which break down into cyanide,are toxic to cells because they inhibit the function of which organelle(s) ?

Accepted Answer

A)  Golgi apparatus
B)  Ribosome
C)  Nucleolus
D)  Mitochondria
E)  Endoplasmic reticulumF) A) and B)
G) C) and D)

Question 14

What is the main difference between plant defense mechanisms that use secondary chemical metabolites versus plant defense mechanisms that use a systemic response?

Accepted Answer

A)  The metabolites are not as lethal as the systemic response.
B)  The metabolites are present at all times,and the systemic response must be induced.
C)  The metabolites can only help in defense against insects,not against other plants.
D)  The metabolites are toxic to the plants that produce them,the systemic response is safer.
E)  The metabolites are a more reliable way to kill the invader.F) B) and D)
G) A) and E)

Question 15

In your garden,you have an Ailanthus altissima,also known as the Tree-of-Heaven.You try adding additional plants to the same garden bed,but notice poor seed germination and seedling growth around the tree.What is the most likely explanation for this?

Accepted Answer

A)  The tree is blocking most of the available sunlight which is limiting germination and growth.
B)  The tree is utilizing most of the available miconutrients in the soil.
C)  The roots of the tree have a stronger water potential than the seedlings which is causing the seedlings to dehydrate.
D)  The tree has a mutalistic relationship with animals that are removing plants that are in competition for resources with the tree.
E)  The tree is releasing chemicals into the soil that are inhibiting germination and growth of other plants.F) C) and E)
G) A) and D)

Question 16

Tannins are chemicals that help plants repel invaders by

Accepted Answer

A)  over-stimulating the predator.
B)  sedating the predator.
C)  binding to proteins and thereby disrupting the predator's digestion.
D)  injuring the external covering of the predator's body.
E)  causing the predator to grow so rapidly that it dies.F) A) and E)
G) C) and D)

Question 17

Why don't ants that protect the Acacia tree scare off bees trying to pollinate the tree's flowers?

Accepted Answer

A)  They can't climb to the tops of the tree.
B)  The bees are too big.
C)  The bees fly in and out quickly.
D)  The open flowers contain a chemical that is an ant deterrent.
E)  Parasitoid wasps protect the bees from attack.F) B) and E)
G) A) and E)

Question 18

Which of the following chemicals is a signal that induces systemic acquired resistance?

Accepted Answer

A)  salicylic acid
B)  brassinosteroids
C)  systemin
D)  avr
E)  nitric acidF) A) and E)
G) All of the above

Question 19

Parasitoid wasps are sometimes involved in a plant's defensive response.In what way are the wasps helpful to the plant?

Accepted Answer

A)  The wasps respond to a chemical the plant gives off when wounded,and the wasps lay their eggs on the caterpillar that wounded the plant.
B)  The wasps live in hollow thorns of the plants,and attack the plants' predators.
C)  The wasps stimulate the production of alkaloids the plants use for defense.
D)  The wasps enhance the plants' hypersensitive response.
E)  The wasps trigger leaf abscission so that herbivores do not have anything to eat.F) B) and D)
G) C) and E)

Question 20

Using biotechnology,plant breeders attempt to find and incorporate specific resistance genes into plants that lack them.Once a plant has been given a resistance gene,it will have indefinite protection from the associated pathogen.

Accepted Answer

A) True 
 B)False

Exam 38: Plant Defense Responses

Nonnative plant invaders,such as the alfalfa plant bug,are extremely invasive and hard to control because

Correct AnswerverifiedShow Answer

Parasitic fungi will usually attack a plant through stomata on the root surface.

Correct AnswerverifiedShow Answer

The steps in the pathogen-specific response do not include

Correct AnswerverifiedShow Answer

Systemic response occurs when plants exhibit generalized defense responses in organs distant from the wound.

Correct AnswerverifiedShow Answer

The activation of proteinase inhibitor genes occurs

Correct AnswerverifiedShow Answer

How does systemin cause the activation of the wound response in tomato plants?

Correct AnswerverifiedShow Answer

Which of the following is a false statement about plant secondary metabolites?

Correct AnswerverifiedShow Answer

Which of the following chemicals is a signal that induces systemic acquired resistance?

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What is the main difference between plant defense mechanisms that use secondary chemical metabolites versus plant defense mechanisms that use a systemic response?

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How does jasmonic acid contribute to the activation of the wound response in tomato plants?

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Viruses travel through animals mainly by lysing cells and then spreading to other cells.Plant cells are not easily lysed.If a pathogen enters a plant cell and does not initiate a hypersensitive response,what is the most likely way the virus would spread to other plant cells?

Correct AnswerverifiedShow Answer

Why don't ants that protect the Acacia tree scare off bees trying to pollinate the tree's flowers?

Correct AnswerverifiedShow Answer

Tannins are chemicals that help plants repel invaders by

Correct AnswerverifiedShow Answer

In your garden,you have an Ailanthus altissima,also known as the Tree-of-Heaven.You try adding additional plants to the same garden bed,but notice poor seed germination and seedling growth around the tree.What is the most likely explanation for this?

Correct AnswerverifiedShow Answer

Which of the following steps is not one of the phases of a fungal invasion of a plant?

Correct AnswerverifiedShow Answer

Which of the following methods do fungi use in order to penetrate the initial layer of a plant's defenses?

Correct AnswerverifiedShow Answer

Cyanogenic glycosides,which break down into cyanide,are toxic to cells because they inhibit the function of which organelle(s) ?

Correct AnswerverifiedShow Answer

Parasitoid wasps are sometimes involved in a plant's defensive response.In what way are the wasps helpful to the plant?

Correct AnswerverifiedShow Answer

Using biotechnology,plant breeders attempt to find and incorporate specific resistance genes into plants that lack them.Once a plant has been given a resistance gene,it will have indefinite protection from the associated pathogen.

Correct AnswerverifiedShow Answer

Which of the following statements about plant toxins against herbivores is false?

Correct AnswerverifiedShow Answer

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