1. Using the various respiratory systems we have covered, discuss how each fulfills the three basic requirements of an exchange system we have discussed (think DAnG).

2. Compare the way a hissing cockroach breathes to the way a blue crab breathes in terms of respiratory surfaces and ventilation mechanisms. Why would the mechanism used by the cockroach not work in an aquatic environment. Are there any crustaceans found in terrestrial environments? If so, what sorts of climates and microclimates do you find them in?

3. Following up on the last question, in what ways is respiration in a crab more similar to yours than it is to a cockroach? In what ways is it different? What, if any, is the role of respiratory pigments in each system? Would the roaches system work for a crayfish? Why or why not?

4. Draw a diagram of the flow of air and blood through the lung of a bird. What is the term used for this special type of lung? Now, diagram the relative concentrations of oxygen in the blood and air of this lung as each passes through during gas exchange. Do the same for carbon dioxide. What animal is this similar to? What familiar type of animal is it quite different from?

5. What is special about the way mammals ventilate their lungs relative to other tetrapods? What muscle(s) are primarily responsible? Contrast the way air is actually moved to what you find in a frog.

6. Carbon monoxide (CO) is a deadly poison for us. At which point in respiration does this compound specifically interfere with function and how does it act? What basic physical limitation on the transport of oxygen in fluids does this effect of carbon monoxide illustrate? Assume that oxygen requirements could still be satisfied in the presence of CO. Would transport of CO2 be greatly affected? Why or why not?

7. On another tack with respect to CO, would you expect this gas to be deadly to a cockroach in the same way it is for us? Why or why not?

8. Imagine this experiment. Two people are breathing from a controlled air source. The air to one person has the CO2 removed before it reaches them (this can be done with a "CO2 scrubber" such as is used in submarines). Which of these two people would you expect to increase breathing rate sooner if at all? Why? Answer with reference to breathing control mechanisms. How specifically does this relate to the primary way or form in which CO2 actually moves in the body?

9. Imagine you saturate hemoglobin with oxygen at the lungs and then it travels to the tissues. Now imagine that you are doing pull ups. Your hemoglobin molecules have traveled to both your bicep muscle and your quadruceps muscles in your legs. In which of these two muscles will hemoglobin release more of the bound oxygen? Think of at least two differences that will cause this difference in oxygen release between your bicep and quadrucep muscles.

10. Related to this question, imagine that you take hemoglobin molecules from both a sheep fetus (a proto-lamb?) and its mother. You mix these two in a solution with oxygen, but not enough oxygen to saturate all the hemoglobin sites on the molecules you have added. Given what you know about these two types of hemoglobin, where would you expect to find most of this oxygen bound later? How much would just be dissolved in your solution and not bound to hemoglobin (made up of mostly water)? Why?
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