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1. When trying to see a faint star at night, it is helpful to look slightly away from the spot where the star is to see it.  Can you think of an explanation for this?

2. Why are we not constantly aware of the touch and pressure of our clothing?

3. What function is common to all sense receptors?

4. In what ways are the compound eye and the human eye similar in function?  In what ways are they different?

5. Most of us have sensed at one time or another an oncoming storm by detecting the increase in humidity in the air. What sort of receptors detect humidity? Why do you suppose that hot days seem so much hotter when it is humid?

6. The heat-detecting pit receptor of snakes is a very effective means of “seeing” at night. It is the same sort of sensory system employed by soldiers in “snooperscopes” and in heat-seeking missiles. Why do you suppose other night-active vertebrates, such as bats, have not evolved this sort sensory system?

7. In zero gravity, how would you expect a statocyst to behave? What would you expect the subjective expression of motion to be? Would the semicircular canals detect angular acceleration equally well at zero gravity?

8. Why haven’t owls developed a sonar sensory system like bats?

9. What parts of the nervous system participate in the maintenance of balance and coordinated body movements?

10. Distinguish between cranial nerves and spinal nerves.

11. Distinguish between a nerve and a neuron.

12. Why do most synapses contain gaps across which an electrical impulse cannot pass, when a direct physical connection would enable the uninhibited passage of the impulse.

13. Why do excitable membranes utilize K+ channels? Why aren’t Na+ ions simply pumped out of the neuron to achieve the internal negative charge, and Na+ ion channels opened to depolarize the membrane?

14. Why can a nerve impulse jump from node to node in salutatory conduction, but not across a synaptic cleft?

15. When the brain is starved for oxygen even briefly, it dies. When the body is starved for energy, it begins to metabolize its own tissues, channeling the products preferentially to the brain. This behavior points out the importance to the brain of ongoing oxidative respiratory mechanism. Why is active oxidative respiration so important to the continued well-being of the brain’s nerve cells?

16. You cannot go for very long without sleep. Do you think fish sleep? How about earthworms? Why do you think sleep has evolved? Would we not be better off if we never had to sleep? Discuss.

17. A monkey will pick up a chair and move it under a shelf so that he can climb up and get food stored on the shelf. Is the monkey “thinking”? Do you imagine that dogs think? Sharks? Or has thinking evolved only in humans?

18. If a person is shocked through the foot, simple reflex withdrawal of the foot will occur.  Describe how this reflex might be "conditioned."  What changes in the functioning of the nervous system occur this process?

19. Summarize the various methods of intraspecific communication found among animals.

20. War is so common among human beings that it must be considered a basic behavior of our species. It appears to be absent in all other animal groups (with the exception of some other primates). Do you think this behavior has a genetic basis? If so, why might its evolution have been favored by natural selection?

21. Swallows often hunt in groups, while hawks and other predatory birds are usually solitary hunters. Can you suggest a plausible explanation for this difference?

22. Can you suggest an evolutionary reason why many vertebrate reproductive groups are composed of one male and numerous females, rather than the reverse?