Tier 1, Round 1
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Transcript of Tier 1, Round 1
Tier 1, Round 1
Section 6.5 (pg. 173 – 184)
Q1: What does CNS and PNS stand for? Which structures in the body constitute
each?
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
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.
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
Q3: What is the “conductor” of a neuron impulse? What does the myelin sheath
do to the action potential?
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.
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?
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.
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 ___-______.
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.
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?
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.
Tier 1, Round 2
Section 6.5 (pg. 173 – 184)
Q7: What is the chemical communication point between pre- and
post- neurons called?
Q7: What is the chemical communication point between pre- and post- neurons called?
• A7:• The chemical communication point between
neurons is the synapse.
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.
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.
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?
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.
Q10: When body temperature is increasing or decreasing too much, the _______ is warned by ________. What are some warming and cooling
mechanisms?
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.
Q11: Negative feedback mechanisms also control blood glucose concentration. What do βcells
secrete? What do α cells secrete? What do these hormones do?
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.
Q12: What is type I diabetes? What is type II diabetes? Which is more
common?
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.
Tier 1, Round 3
Section E.1 (pg. 461 – 464)
Q13: Define the terms stimulus, reflex and response.
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.
Q14: Draw a (rudimentary) picture of the spinal cord and the components of
a reflex arc. Label it, too.
Q14: Draw a (rudimentary) picture of the spinal cord and
the components of a reflex arc. Label it, too.
• A14:
Q15: How are natural selection and the responses of animals to their
environment related?
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.
Q16: Explain the advantageous behavior exhibited by a segment of the population of European blackcaps in terms of migration.
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.
Q17: Explain the advantageous behavior exhibited by two segments of the population
of Sockeye salmon in terms of habitat.
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.
Q18: Jellyfish belong to which phylum?
Q18: Jellyfish belong to which phylum?
• A18:• cnidaria
Tier 1, Round 4
Section E.4 (pg. 481 – 489)
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?
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.
Q20: What happens when the action potential reaches the axon bulb?
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.
Q21: What do excitatory neurotransmitters do, and how do they
work?
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.
Q22: What do inhibitory neurotransmitters do, and how do they
work?
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.
Q23: What is acetylcholine, and with what types of synapses is it used? How
does acetylcholine work?
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.
Q24: What is noradrenaline, and with what types of synapses is it used? How
does acetylcholine work?
Q24: What is noradrenaline, and with what types of
synapses is it used? How does noradrenaline work?
• A24:• Noradrenaline is a neurotransmitter that
works with adrenergic synapses.• Noradrenalinealsodepolarizes the
postsynaptic membrane, causing the creation of another action potential.• Noradrenaline is involved with the
sympathetic nervous system, meaning it spazzes you out.
Tier 1, Round 5
Section E.4 (pg. 481 – 489)
Q25: Name some of the ways in which drugs affect the brain.
Q25: Name some of the ways in which drugs affect
the brain.
• A25:• block a receptor for a neurotransmitter• block release of a neurotransmitter• enhance release of a neurotransmitter• mimic a neurotransmitter• block removal of a neurotransmitter
Q26: How do excitatory drugs behave?
Q26: How do excitatory drugs behave?
• A26:• Nicotine mimics acetylcholine, but it cannot
be broken down by acetylcholinesterase, so the effect lingers.• Nicotine causes dopamine to be released.• Cocaine and amphetamine stimulate
transmission at adrenergic synapses and so makes you alert and euphoric.• Cocaine blocks dopamine removal from the
synapse, and amphetamine stops it from being broken down.
Q27: How do inhibitory drugs behave?
Q27: How do inhibitory drugs behave?
• A27:• Benzodiazepine and alcohol increase the binding
of GABA, the main inhibitory neurotransmitter, to the postsynaptic neuron.
• Both drugs cause the postsynaptic neuron to become hyperpolarized, inhibiting further action potentials.
• These drugs produce a feeling of sedation, and somehow alcohol also increases dopamine concentration.
• Tetrahydrocannabinol binds to the same receptors as anandamide and cause hyperpolarization.
Q28: How do THC and cocaine affect mood, synapse and behavior?
Q28: How do THC and cocaine affect mood,
synapse and behavior?
• A28:• THC affects learning, coordination, problem
solving and short-term memory negatively.• Cocaine makes you gabby, alert and
euphoric, and you stop feeling the need to eat and drink. Essentially, it makes you spazzy, so large amounts of it make you behave “erratically” and “violently.”
Q29: Explain the three main factors in addiction: genetic predisposition, social
factors and dopamine secretion.
Q29: Explain the three main factors in addiction: genetic
predisposition, social factors and dopamine secretion.
• A29:• Using twin experiments, scientists have discovered that
if one identical male twin has an addiction, the other twin is 50% more likely to have an addiction as well.
• A deficiency in dopamine receptors also causes an increased susceptibility to addiction.
• If a child is surrounded by drug addicts, he or she is more likely to become a drug addict him or herself.
• Constant stimulation of dopamine receptors causes them to become progressively less responsive to dopamine; in order to get the same sensation desired from a drug, greater and greater quantities must be taken.
Q30: What type of inheritance accounts for wide variation in traits such as eye
and skin color?
Q30: What type of inheritance accounts for wide variation
in traits such as eye and skin color?
• A30:• polygenic inheritance
Tier 2
Lightning Round!
QL1: List the nine steps involved in the mechanism of synaptic transmission.
QL1: List the nine steps involved in the mechanism
of synaptic transmission.
• AL1:1. Calcium ions diffuse into the terminal buttons.2. Vesicles containing neurotransmitter fuse with the plasma membrane and release
the neurotransmitters.3. Neurotransmitter diffuses across the synaptic gap from the presynaptic neuron to
the postsynaptic neuron.4. Neurotransmitter binds with a receptor protein on the postsynaptic neuron
membrane.5. This binding results in an ion channel opening and sodium ions diffusing in through
this channel.6. This initiates the action potential to begin moving down the postsynaptic neuron
because it is depolarized.7. Neurotransmitter is degraded by specific enzymes and is released from the receptor
protein.8. The ion channel closes to sodium ions.9. Neurotransmitter fragments diffuse back across the synaptic gap to be reassembled
in the terminal buttons of the presynaptic neuron.