Some species of orchids attract pollinating Hymenoptera (bees and wasps) with flowers that closely mimic the appearance of a female insect. As the male attempts to mate with the flower, he becomes loaded with pollen, helping the plant to reproduce. If one of these orchid plants acquired a loss-of-function mutation in a CYCLOIDEA-like gene, what do you predict might happen?

Question

A.  The mutation would quickly spread through the population.
B.  The mutant plants would have fewer available resources to devote to nectar production.
C.  The mutant plants would attract larger numbers of pollinating male insects.
D.  The mutation would fail to spread in the population.

Clarify Question
What is the key concept addressed by the question?
What type of thinking is required?
What do you already know about insects as pollinators? 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

D.  The mutation would fail to spread in the population.

Clarify Question
What is the key concept addressed by the question?
        · This question is asking about the effects of a loss-of-function mutation in a CYCLOIDEA-like gene.
What type of thinking is required?
        · Apply level:
            o You are being asked to take what you already know and apply it to the effects of a mutation in an insect-pollinated plant. Gather Content
What do you already know about insects as pollinators? What other information is related to the question?
        · Insect-mimicking orchids use bilaterally symmetric flowers to mimic the bilateral symmetry of the female bee or wasp.
        · When the CYCLOIDEA gene mutates, radially symmetrical flowers result.

Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
        · Since the mutant phenotype of CYCLOIDEA is to produce radial flowers, they would no longer resemble the female insect and would fail to be pollinated by the males.
        · Without the spread of pollen, this mutation would not persist.

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?
        · Apply level:
            o Answering this question correctly depended on your ability to use the expression of the CYCLOIDEA gene in a new situation. If you got an incorrect answer, did you remember that a mutation in the CYCLOIDEA gene changes the shape of a flower, or that insect-pollinated orchids attract insects by maintaining a specific flower shape? Did you have trouble extending the importance of flower shape to determine the correct answer?