Critical Thinking Questions
29. How does diffusion limit the size of an organism? How is this counteracted?
30. What is the relationship between BMR and body size? Why?
31. Explain how using an open circulatory system constrains the size of animals.
32. Describe one key environmental constraint for ectotherms and one for endotherms. Why are they limited by different factors?
33. How can squamous epithelia both facilitate diffusion and prevent damage from abrasion?
34. What are the similarities between cartilage and bone?
35. Multiple sclerosis is a debilitating autoimmune disease that results in the loss of the insulation around neuron axons. What cell type is the immune system attacking, and how does this disrupt the transfer of messages by the nervous system?
36. When a person leads a sedentary life his skeletal muscles atrophy, but his smooth muscles do not. Why?
37. Why are negative feedback loops used to control body homeostasis?
38. Why is a fever a “good thing” during a bacterial infection?
39. How is a condition such as diabetes a good example of the failure of a set point in humans?
40. On a molecular level, how can endotherms produce their own heat by adjusting processes associated with cellular respiration? If needed, review Ch. 7 for details on respiration.