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

Question

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.
E.  R genes will fail to match up with avr genes.

Clarify Question
· What is the key concept addressed by the question?
· What type of thinking is required?
does the question contain and what do they mean?

Gather Content
· What do you already know about about the function of systemin? How does it relate to the question?

Consider Possibilities
· What other information is related to the question? Which information is most useful?

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?

Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

Answer 1

D.  Systemin receptors will not be activated and proteinase inhibitor will not be transcribed.

Clarify Question
· What is the key concept addressed by the question?
        o The question is asking what will occur if systemin is absent.
· What type of thinking is required?
        o This question is asking you to evaluate the function of systemin. · What key words does the question contain and what do they mean?
        o Mutation, which is a mistake or a misreading of the genetic code.
        o Systemin, which is a protein in plants.

Gather Content
· What do you already know about about the function of systemin? How does it relate to the question?
        o Mutations can cause proteins to be nonfunctional.
        o Systemin is a protein involved in defense response in plants.
        o When systemin is present, it triggers the production of jasmonic acid.
        o Jasmonic acid facilitates the defense response.
        o Proteinase inhibitor is a protein used in the defense response.

Consider Possibilities
· What other information is related to the question? Which information is most useful?
        o A mutation would likely cause systemin to go unrecognized.
        o Without systemin, jasmonic acid would not be produced.
        o R genes and avr genes are involved in pathogen recognition and response.

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
        o Removing systemin, as would happen with a mutation, would stop the defense response pathway. If this pathway is inhibited, proteinase inhibitor would not be produced.

Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
· Evaluate level:
This question asked you to evaluate the effect of the loss of systemin. Answering this question correctly depended on your ability to evaluate what would occur if systemin is removed from the plant. If you got the correct answer, well done! If you got an incorrect answer, where did the process break down? Did you remember that systemin is necessary for the defense response, or the that production of proteinase inhibitor is an end result of the defense pathway? Did you have trouble weighing the merits of the presence of systemin in the defense pathway to determine the correct answer?