Tier 1, Round 1

1. Tier 1, Round 1 Section 6.5 (pg. 173 – 184)

2. Q1: What does CNS and PNS stand for? Which structures in the body constitute each?

3. Q1: What does CNS and PNS stand for? Which structures in the body constitute each? • A1: • CNS is central nervous system • PNS is peripheral nervous system • CNS is composed of the brain and spinal cord • PNS is composed of the spinal nervesand cranial nerves

4. Q2: Arrange the following in the correct order: sensory receptor, effector cells, motor neurons, sensory neurons, relay neurons. Say which neurons belong to the CNS and which belong to the PNS.

5. Q2: Arrange the following in the correct order: sensory receptor, effector cells, motor neurons, sensory neurons, relay neurons. Say which neurons belong to the CNS and which belong to the PNS. • A2: • sensory receptor > sensory neurons (PNS) > relay neurons (CNS) > motor neurons (PNS) > effector cells

6. Q3: What is the “conductor” of a neuron impulse? What does the myelin sheath do to the action potential?

7. Q3: What is the “conductor” of an action potential? What does the myelin sheath do to the action potential? • A3: • The “conductor” of an action potential is the axon. • The myelin sheath greatly increases the rate at which an action potential passes down an axon.

8. Q4: During the resting potential, most Na+ are ____ transported ___ __ the axon and most K+ are transported ___ the cytoplasm. What other kinds of ions are present, and what do they do?

9. Q4: During the resting potential, most Na+ are ____ transported ___ __ the axon and most K+ are transported ___ the cytoplasm. What other kinds of ions are present, and what do they do? • A4: • Most Na+ are activelytransported out ofthe axon. • Most K+ are transported intothe cytoplasm. • The other ions are negatively charged organic ionsthat create a net positivecharge outside the axon and a net negative charge inside the axon.

10. Q5: In an action potential, Na+ diffuses ___ and then K+ diffuses ___. This process is called _______, which is the ‘impulse.’ Once an impulse begins, it continues to the end of the cell; this is ___-______.

11. Q5: In an action potential, Na+ diffuses ___ and then K+ diffuses ___. This process is called _______, which is the ‘impulse.’ Once an impulse begins, it continues to the end of the cell; this is ___-______. • A5: • In an action potential, Na+ diffuses inand then K+ diffuses out. • This process is called depolarization, which is the ‘impulse.’ • Once an impulse begins, it continues to the end of the cell; this is self-propagation.

12. Q6: Once an action potential is sent, what is the process by which Na+ and K+ are returned to their resting potential places? How is this accomplished?

13. Q6: Once an action potential is sent, what is the process by which Na+ and K+ are returned to their resting potential places? How is this accomplished? • A6: • The process by which Na+ and K+ are returned to their resting potential places is repolarization. • This is accomplished by active transport.

14. Tier 1, Round 2 Section 6.5 (pg. 173 – 184)

15. Q7: What is the chemical communication point between pre- and post- neurons called?

16. Q7: What is the chemical communication point between pre- and post- neurons called? • A7: • The chemical communication point between neurons is the synapse.

17. Q8: What is the process by which physiological variables are kept within certain limits? Name four of the five physiological variables listed in the book.

18. Q8: What is the process by which physiological variables are kept within certain limits? Name four of the five physiological variables listed in the book. • A8: • This process is called homeostasis. • Acceptable variables are blood pH, [CO2], [C6H12O6], body temperature, and water balance.

19. Q9: What are the physiological changes that tell the body to adjust a value back to a certain point called? Homeostatic mechanism are controlled by what?

20. Q9: What are the physiological changes that tell the body to adjust a value back to a certain point called? Homeostatic mechanism are controlled by what? • A9: • These physiological changes are called negative feedback mechanisms. • Homeostatic mechanisms are mostly controlled by the autonomic nervous system.

21. Q10: When body temperature is increasing or decreasing too much, the _______ is warned by ________. What are some warming and cooling mechanisms?

22. Q10: When body temperature is increasing or decreasing too much, the _______ is warned by ________. What are some warming and cooling mechanisms? • A10: • When body temperature is increasing or decreasing too much, the hypothalamus is warned by thermoreceptors. • Cooling mechanisms: sweatingand arteriole dilation. • Warming mechanisms: arteriole constrictionand shivering.

23. Q11: Negative feedback mechanisms also control blood glucose concentration. What do βcells secrete? What do α cells secrete? What do these hormones do?

24. Q11: Negative feedback mechanisms also control blood glucose concentration. What do β cells secrete? What do α cells secrete? What do these hormones do? • A11: • In the pancreas, β cells secrete insulin, and α cells secrete glucagon. • The secretion of insulin causes hepatocytes to take in glucose and convert it to glycogen. • The secretion of glucagon causes hydrolysis of glycogen in hepatocytes to release glucose.

25. Q12: What is type I diabetes? What is type II diabetes? Which is more common?

26. Q12: What is type I diabetes? What is type II diabetes? Which is more common? • A12: • Type I diabetes is the form of the disease in which the immune system destroys its own β cells. • Type II diabetes is the form of the disease in which the body no longer responds to insulin as it should—this is called insulin resistance, and this is the more common form of the disease by far.

27. Tier 1, Round 3 Section E.1 (pg. 461 – 464)

28. Q13: Define the terms stimulus, reflex and response.

29. Q13: Define the terms stimulus, reflex and response. • A13: • A stimulus is a change in the environment that is detected by a receptor and elicits a response. • A reflex is a rapid, unconscious response. • A response is a reaction to a stimulus.

30. Q14: Draw a (rudimentary) picture of the spinal cord and the components of a reflex arc. Label it, too.

31. Q14: Draw a (rudimentary) picture of the spinal cord and the components of a reflex arc. Label it, too. • A14:

32. Q15: How are natural selection and the responses of animals to their environment related?

33. Q15: How are natural selection and the responses of animals to their environment related? • A15: • An animal’s response to its environment can be considered a series of reflexes. • Some responses allow an animal respond to its environment more advantageously than another animal with different responses. • Animals with advantageous variations in their responses survive to reproduce more frequently than those with detrimental variations. Thus, the genetic programming for a particular behavior pattern propagates throughout the population.

34. Q16: Explain the advantageous behavior exhibited by a segment of the population of European blackcaps in terms of migration.

35. Q16: Explain the advantageous behavior exhibited by a segment of the population of European blackcaps in terms of migration. • A16: • European blackcaps generally migrate from Germany in the summer to Spain in the winter. Some European blackcaps started migrating to the UK instead. These blackcaps left the UK 10 days earlier than the Spanish wintering birds, and so received the choices places to lay eggs. More eggs were laid by UK birds than Spanish birds.

36. Q17: Explain the advantageous behavior exhibited by two segments of the population of Sockeye salmon in terms of habitat.

37. Q17: Explain the advantageous behavior exhibited by two segments of the population of Sockeye salmon in terms of habitat. • A17: • There are two types of habitat: slow, deep Lake Washington and fast, shallow Cedar River. They’re connected to each other. • There are two types of males: lake males who are fat and river males who are thin and narrow. • These two segments stopped interbreeding, because it does no good to have a fat fish in a river. • Voilà. Now there are two different populations because each was selected by it’s environment.

38. Q18: Jellyfish belong to which phylum?

39. Q18: Jellyfish belong to which phylum? • A18: • cnidaria

40. Tier 1, Round 4 Section E.4 (pg. 481 – 489)

41. Q19: What are the molecules that move across the synaptic cleft? What receives these molecules? What are the two types of molecules that move across the synaptic cleft?

42. Q19: What are the molecules that move across the synaptic cleft? What receives these molecules? What are the two types of molecules that move across the synaptic cleft? • A19: • The molecules that move across the synaptic cleft are called neurotransmitters. • These molecules are received by receptor molecules. • The two types of neurotransmitters are excitatoryand inhibitory.

43. Q20: What happens when the action potential reaches the axon bulb?

44. Q20: What happens when the action potential reaches the axon bulb? • A20: • Ca2+ rush into the end of the neuron, causing vesicles containing neurotransmitters to fuse with the presynaptic membrane (i.e. the neurotransmitters are dumped into the synaptic cleft). • The neurotransmitters then bind to specific receptors on the postsynaptic membrane.

45. Q21: What do excitatory neurotransmitters do, and how do they work?

46. Q21: What do excitatory neurotransmitters do, and how do they work? • A21: • Excitatory neurotransmitters generate an action potential. • Excitatory neurotransmitters make the postsynaptic membrane especially permeable to positive ions (such as Na+). Positive ions rush in, making the inside of the neuron positive. This launches a depolarization of that particular part of the neuron. • Depolarization self-propagates as per usual, with Na+ diffusing in and K+ diffusing out.

47. Q22: What do inhibitory neurotransmitters do, and how do they work?

48. Q22: What do inhibitory neurotransmitters do, and how do they work? • A22: • Inhibitory neurotransmitters stop an action potential from continuing to the postsynaptic neuron. • Inhibitory neurotransmitters bind to a specific receptor and causes hyperpolarization. • Hyperpolarization makes the inside of the neuron more negative than it was to begin with by moving Cl- in and/or K+ out.

49. Q23: What is acetylcholine, and with what types of synapses is it used? How does acetylcholine work?

50. Q23: What is acetylcholine, and with what types of synapses is it used? How does acetylcholine work? • A23: • Acetylcholine is a neurotransmitter that works with cholinergic synapses. • Ach depolarizes the postsynaptic membrane, causing the creation of another action potential. • Acetylcholinesterase breaks down Ach so it doesn’t go on depolarizing. • Ach is involved with the parasympathetic nervous system, meaning it relaxes.