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. D

Question 2

Which of the following statements about the pathogen-specific response is true?

Accepted Answer

A)  The pathways involved always trigger the hypersensitive response.
B)  The pathogen is recognized by its avr gene product.
C)  There is never a gene-for-gene response.
D)  If the R gene product is not triggered, no disease will occur. B

Question 3

A plant has a mutation in the gene that codes for systemin.What is the likely consequence of this mutation?

Accepted Answer

A)  The plant will have a stronger than normal wound response.
B)  The mutated form of systemin would be recognized as a pathogen and a hypersensitive response will be initiated.
C)  The levels of jasmonic acid will build inside the cell creating a toxic environment.
D)  Systemin receptors will not be activated and proteinase inhibitor will not be transcribed. D

Question 4

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.

Question 5

The series of metabolic events that occurs within tomato plants in response to wounding is

Accepted Answer

A)  a systemic response.
B)  a waterfall effect.
C)  the hypersensitive response.
D)  a pathogen-specific response.

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.

Question 7

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

Question 8

If a bacterium containing a mutation in the avirulence gene lands on a plant that has the corresponding R gene, the bacterium may not initiate rapid cell death in the plant.

Accepted Answer

A) True 
 B)False

Question 9

A patient who requires repeated dosing with strong analgesics over a period of more than a few days might be prescribed which of the following secondary plant metabolites?

Accepted Answer

A)  Genistein
B)  Morphine
C)  Quinine
D)  Taxol

Question 10

Plants such as peppermint and sage contain oils.What is the function of these oils?

Accepted Answer

A)  They help keep the plant from drying out.
B)  They help repel insects.
C)  They keep other plants from germinating nearby.
D)  They prevent fungal infection.

Question 11

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.

Question 12

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.

Question 13

Which of the following plant secondary metabolites is used as an antimalarial drug?

Accepted Answer

A)  morphine
B)  taxol
C)  genistein
D)  quinine

Question 14

____________ occurs when a chemical signal secreted by the roots of one plant blocks the germination of nearby seeds or inhibits the growth of a neighboring plant.

Accepted Answer

A)  Nodulation
B)  Etiolation
C)  Reduction
D)  Allelopathy

Question 15

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.

Question 16

The plant alkaloid ricin is nontoxic inside castor beans, but becomes active when digested by an animal.The toxic form of ricin kills by

Accepted Answer

A)  inactivating the animal's immune system.
B)  over stimulating the animal's heart rate.
C)  inactivating ribosomes needed for translation.
D)  binding to RNA polymerase.

Question 17

Treating a plant with a fungicide could interfere with the plant's uptake of nitrogen.

Accepted Answer

A) True 
 B)False

Question 18

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.

Question 19

A nematode that has parasitized a plant has breached the cutin layer of the epidermis.

Accepted Answer

A) True 
 B)False

Question 20

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.

Exam 39: Plant Defense Responses

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

Which of the following statements about the pathogen-specific response is true?

A plant has a mutation in the gene that codes for systemin.What is the likely consequence of this mutation?

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

The series of metabolic events that occurs within tomato plants in response to wounding is

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

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.

If a bacterium containing a mutation in the avirulence gene lands on a plant that has the corresponding R gene, the bacterium may not initiate rapid cell death in the plant.

A patient who requires repeated dosing with strong analgesics over a period of more than a few days might be prescribed which of the following secondary plant metabolites?

Plants such as peppermint and sage contain oils.What is the function of these oils?

The activation of proteinase inhibitor genes occurs

The steps in the pathogen-specific response do not include

Which of the following plant secondary metabolites is used as an antimalarial drug?

____________ occurs when a chemical signal secreted by the roots of one plant blocks the germination of nearby seeds or inhibits the growth of a neighboring plant.

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

The plant alkaloid ricin is nontoxic inside castor beans, but becomes active when digested by an animal.The toxic form of ricin kills by

Treating a plant with a fungicide could interfere with the plant's uptake of nitrogen.

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?

A nematode that has parasitized a plant has breached the cutin layer of the epidermis.

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