If genetically engineered bees could express a receptor for TNT in their olfactory neurons, how would the bees respond to the presence of TNT?

Question

A.  It would ignore the stimulus.
B.  It would be attracted.
C.  It would be repelled.
D.  It would depend on which olfactory neuron expresses the transgene.

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 olfaction? 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.  It would depend on which olfactory neuron expresses the transgene.

Clarify Question
What is the key concept addressed by the question?
        · How would the transgenic bees respond to TDT?
What type of thinking is required?
            o This is an analyze question because you have to break sensory (olfaction) signaling into different stages and understand what activates the receptors involved and how this effects behavior.

Gather Content
What do you already know about olfaction? What other information is related to the question?
        · You already know that olfaction detects odorants when odorants bind to specific olfactory receptors and opening up ion channels, producing receptor potentials. What would happen if you express a novel olfactory receptor for TDT on honeybee antennae? The honeybee would be able to sense or smell the TDT since TDT, which is a chemical, binds to the receptor on an olfactory neuron. How the bee responds to this stimulus would depend upon which olfactory neuron the receptors are on. If the receptor is co-expressed with other receptors that bind to floral chemicals signaling flowers and a source of pollen, then TDT would attract the bees. If the TDT receptor is co-expressed with other receptors that bind to putrid chemicals or chemicals signaling enemies, then TDT would repel the bees.

Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
        · Since the TDT receptor that you have genetically engineered in the honeybee antennae is an olfactory receptor, and TDT is a chemical that binds to and activates the receptor, it will depend upon which type of olfactory neuron the receptors are expressed. If they are expressed on olfactory neurons that usually attract bees when activated, then TDT would attract them. If they are expressed on olfactory neurons that usually repel bees when activated, then TDT would also repel them.

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?
        o Answering this question correctly depended not only on understanding the steps of the sensory pathway of olfaction, but on your ability to understand how the change in this system by genetic engineering can provide an additional olfactory receptor for the honeybee and determining the behavior effect of activating these receptors. If you got an incorrect answer, did you realize that these novel receptors would be expressed on olfactory neurons that expressed receptors for other odors? Did you think that because TDT does not normally have an olfactory receptor in honeybees that binding this receptor would elicit no behaviors?