AP BIOLOGY STUDY GUIDE
SENSE ORGANS, NERVOUS SYSTEM, AND BEHAVIOR
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?