An entomologist observed a locust sitting on a branch pumping its abdomen like an accordion. What is the insect most likely doing?

Question

A.  Speeding the flow of blood through its veins and arteries
B.  Assisting gas exchange in the tracheal system
C.  Clearing its spinnerets
D.  Stretching out its pedipalps

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 insect respiration?

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

B.  Assisting gas exchange in the tracheal system

Clarify Question
· What is the key concept addressed by the question?
        o This question addresses insect respiration.
· What type of thinking is required?
        o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer.

Gather Content
· What do you already know about insect respiration?
        o The insect respiratory system consists of small, branched ducts called tracheae.
        o Very small tracheoles allow oxygen and carbon dioxide to diffuse directly into individual cells.
        o Since insects depend on the respiratory system (not the circulatory system) to carry oxygen to their tissues, all parts of the body must be near a respiratory passage, limiting their maximum size.
        o Air passes into the tracheae through openings in the exoskeleton called spiracles along the thorax and abdomen.

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
        o Could the locust be speeding the flow of blood through its veins and arteries? No, because insects do not have veins and arteries – they have an open circulatory system.
        o Could the locust be clearing its spinnerets? No, because spiders have spinnerets, but locusts don’t.
        o Could the locust be stretching out its pedipalps? No, pedipalps are mouthparts on the head, not the abdomen.
        o Could the locust be assisting gas exchange in the tracheal system? Yes. Spiracles are openings to the trachea along the abdomen, and movement of the abdomen can help pump air in and out of the spiracles.

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 The question required you to analyze the information given, using logic, to dissect the problem and determine the answer.
        o Did you recognize that insects have respiratory openings along their abdomen?