Rank the sensory receptors in order, from the ability to detect the widest variety of molecules, to the least variety of molecules (or none).

Question

__   photoreceptors
__   TRP channel temperature receptors
__   gustatory receptors
__   olfactory receptors

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 sensory receptors? 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

4   photoreceptors
3   TRP channel temperature receptors
2   gustatory receptors
1   olfactory receptors

Clarify Question
What is the key concept addressed by the question?
        · How do sensory receptors rank in terms of variety of molecules that can stimulate them?
What type of thinking is required?
            o This is an analyze question because you have to break sensory receptors into different types and understand the variability of stimuli that can activate each type of receptor.
 
Gather Content
What do you already know about sensory receptors? What other information is related to the question?
        · You already know that each sensory receptor is responsible for a different sense. Olfactory receptors are used in olfaction, or smell. TRP channel receptors detect temperature. Photoreceptors are located in the retina to detect light for vision. Gustatory receptors are used in gustation, or taste. Of these receptor types, TRP channel thermoreceptors and photoreceptors are not normally activated by molecules (heat or cold activate thermoreceptors and photons of light activate photoreceptors), although some molecules, like capsaicin and menthol, can activate hot and cold thermoreceptors, respectively. Olfactory receptors are the most diverse type of receptors that can recognize thousands of different odors. Gustatory receptors detect five taste categories (sweet, sour, salty, bitter and umami) and so must have about five different types of gustatory receptors.
 
Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
        · Olfactory receptors are the most diverse type of sensory receptor, with their numbers in the thousands, so these must be able to detect the widest variety of molecules. Gustatory receptors have at least five types, so it must be the second most diverse in terms of molecules that activate them.TRP channels are activated by hot or cold, but are also activated by a few molecules, like capsaicin, menthol, and vanillin, so it would be the third most diverse. Lastly, photoreceptors are not activated by any molecules, but by light, and so represent the least most diverse.
 
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 distinguishing between the four sensory receptor types, but on your ability to analyze the variety of molecules that can activate each type. If you got an incorrect answer, did you remember that photoreceptors are activated by light and not molecules? Did you remember that TRP channels, although primarily used to detect temperature, can also be activated by a few molecules like capsaicin, menthol, or vanillin?