You are studying a mutant gene in the fruit fly Drosophila, and you suspect it may be important for eye development. What evidence would support such a claim? (Check all that apply)

Question

_____  Gene expression in the eye primordia 
_____  Gene expression throughout the head 
_____  Misexpression of wildtype gene results in ectopic eyes 
_____  Misexpression of wildtype gene results in missing or malformed eyes 
_____  Mutant with nonfunctional gene has ectopic eyes 
_____  Mutant with nonfunctional gene has malformed eyes


Clarify Question
What is the key concept addressed by the question?

What type of thinking is required?


Gather Content
What do you already know about the development of structures in an individual? What other information is related to the question?


Choose Answer
Given what you now know, what information 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

__X__  Gene expression in the eye primordia 
_____  Gene expression throughout the head 
__X__  Misexpression of wildtype gene results in ectopic eyes 
_____  Misexpression of wildtype gene results in missing or malformed eyes 
_____  Mutant with nonfunctional gene has ectopic eyes 
__X__  Mutant with nonfunctional gene has malformed eyes

Clarify Question
What is the key concept addressed by the question?
   · The concept addressed here is the identification of the underlying factors that are used to identify gene function.

What type of thinking is required?
   · Evaluate level:
    o This question is asking you to weigh and judge, or evaluate, the evidence that can support the identification of the function of a gene.


Gather Content
What do you already know about the development of structures in an individual? What other information is related to the question?
   · In general, structures arise from foundational tissues that are known as primordia.
   · Whether a gene contributes to the formation of a structure can be assessed by looking at the structure when the gene is expressed normally, but also when the gene is expressed abnormally.
   · If a gene regulates the development of a structure, it would be expressed in the primordia.
   · If the gene is mutated, such that it was nonfunctional, or if the gene is misexpressed, the structure would not be expected to develop normally.


Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
   · If the gene is expressed throughout the head, it could be ruled out as specific to eye development.
   · Misexpression of the gene would not result in missing eyes if the gene does in fact regulate eye development.
   · To demonstrate that the gene is involved in eye development, the gene would need to be present in the eye primordia.
   · The development of ectopic eyes would be an expected result if a gene involved in eye development was misexpressed.
   · Malformed eyes would be an expected result if a gene involved in eye development was mutated such that it was nonfunctional.


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:
    o Answering this question correctly depended on your ability to weight and judge, or evaluate, eye development and gene expression. If you got an incorrect answer, did you remember that a mutated gene that results in a nonfunctional gene product would result in abnormal eye structure, or that to contribute to the development of a structure like the eye, the gene would be expressed in the primordial tissue of the eye? Did you have trouble weighing the merits of eye development relative to gene expression to determine the correct answer?