Which one of the following insect organ systems has placed the greatest limitation on their body size?

Question

A.  nervous system
B.  digestive system
C.  respiratory system
D.  reproductive system
E.  excretory system

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 insects?

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

C.  respiratory system

Clarify Question
· What is the key concept addressed by the question?
        o This question addresses insects.
· What type of thinking is required?
        o This question is asking you to weigh and judge evidence, or evaluate, to choose the best of the possible answers.

Gather Content
· What do you already know about insects?
        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 spiracles which are openings in the exoskeleton 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 The respiratory system of insects does not allow them to grow too big, because oxygen must be able to diffuse to each cell.
        o Larger insects could survive in the past when oxygen levels were higher.

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 weigh and judge evidence, or evaluate, to choose the best of the possible answers.
        o Did you recognize that the insect respiratory system places an upper limit on body size, since oxygen must diffuse from the trachea to each cell?