Deck 6: Physiological Analysis-Nerve Cells and Behavior

Question 1

An afferent neuron

A) carries information away from the central nervous system.
B) carries information into the central nervous system.
C) processes information within the central nervous system.
D) serves the same function in vertebrates that an efferent neuron performs in invertebrates.

Answer 1

carries information into the central nervous system.

Question 2

The long cable like neurite that transmits information to other neurons is called a(n)

A) axon.
B) dendrite.
C) glial cell.
D) soma.

Answer 2

axon.

Question 3

The myelin sheath

A) cleans up debris in the neuron.
B) stimulates neurons to fire.
C) allows axons to transmit information faster.
D) retards the rate of neural transmission.

Answer 3

allows axons to transmit information faster.

Question 4

During the resting potential

A) the area just inside the membrane of a neuron is about 60 millivolts more positive than the fluid immediately outside the membrane.
B) the concentration of sodium ions is much greater outside the neuron than within it.
C) the membrane of the neuron would be described as being depolarized.
D) the neuron is relaying a message.

Question 5

A nerve impulse (action potential) is caused initially by the

A) inward movement of potassium ions.
B) inward movement of sodium ions
C) outward movement of potassium ions.
D) outward movement of sodium ions.

Question 6

The refractory period, while brief, is a biologically significant phase of the signal transmission process because

A) during the absolute refractory period, a stronger than normal stimulus will cause the neuron to fire.
B) during the relative refractory period, a weaker than normal stimulus will cause the neuron to fire.
C) it can last for up to 50 milliseconds.
D) it determines the neuron's rate of maximum firing.

Question 7

For many species, neurons fire only if they meet a certain threshold. In other words, these neurons do not emit a partial response. This describes the

A) absolute refractory period.
B) all-or-none phenomenon.
C) resting potential.
D) sodium-potassium pump.

Question 8

The intensity of a stimulus, e.g., the difference between a dim light and a bright light, is coded

A) by the firing rate of the neuron.
B) by the intensity of each neural transmission traveling down the axon.
C) by the number of neurons firing.
D) by the firing rate of the neuron and by the number of neurons firing.

Question 9

Occasionally one sees a fruit fly (Drosophila melanogaster) that shakes its legs, wings, or abdomen under ether anesthesia. This behavior is caused by a mutation that results in

A) a reduced amount of neurotransmitter being released.
B) certain potassium channels not being formed, disrupting the normal flow of potassium across the membrane.
C) highly coordinated muscle contractions due to the unusually synchronized neural firing.
D) the mutant neurons repolarizing more quickly than they should.

Question 10

The area of the nervous system that determines whether the message of one neuron will generate an action potential in the next neuron is the

A) dendrite.
B) neuromodulator.
C) repolarizor.
D) synapse.

Question 11

Although electrical synapses are much less common than chemical synapses, they are known for their speed of transmission and, thus, are most likely part of the neural circuitry that underlies

A) courtship behaviors.
B) escape behaviors.
C) feeding behaviors.
D) learning.

Question 12

Electrical synapses differ from chemical synapses in that electrical synapses

A) are characterized by a space between neurons that is approximately 20-30 nm wide.
B) bridge the space between neurons with tiny tubes, allowing the direct flow of ions.
C) make use of neurotransmitters to communicate with the post-synaptic neuron.
D) result in a somewhat slower rate of transmission than chemical synapses.

Question 13

The small storage sacs containing the neurotransmitter in the presynaptic neuron are called

A) calcium channels.
B) neuromodulators.
C) synaptic vesicles.
D) terminal boutons.

Question 14

When a neurotransmitter binds to the receptor on a postsynaptic neuron it may result in an EPSP which

A) hyperpolarizes the membrane of the postsynaptic neuron.
B) increases the probability that the postsynaptic neuron will fire.
C) results in the exit of positively charged potassium ions or the influx of negatively charged chloride ions in the post synaptic neuron.
D) results in all of the above.

Question 15

Breaking the neurotransmitter down with an enzyme so that its component parts can be absorbed for resynthesis, or molecules of the neurotransmitter being released intact from the postsynaptic cell so that it can absorbed and repackaged are ways to

A) halt the effect of a neurotransmitter.
B) intensify the effect of a neurotransmitter.
C) prolong the effect of a neurotransmitter.
D) accomplish all the above effects.

Question 16

Having received messages from hundreds or thousands of other neurons, a postsynaptic neuron will fire if

A) all of its incoming messages are inhibitory in nature.
B) it is being stimulated by neuromodulators rather than simple neurotransmitters.
C) the combined incoming excitatory and inhibitory signals produce a large enough depolarization.
D) the combined incoming excitatory and inhibitory signals produce a large enough hyperpolarization.

Question 17

Neuromodulators are chemicals that alter neuronal activity. Their effects are generally

A) faster than both neurotransmitters and hormones.
B) faster than neurotransmitters but slower than hormones.
C) slower than both neurotransmitters and hormones.
D) slower than neurotransmitters but faster than hormones.

Question 18

Chemicals whose effects are mediated by substances within a postsynaptic neuron called second messengers, such as calcium or cAMP, are known as

A) hormones.
B) neuromodulators.
C) neurotransmitters.
D) all of the above.

Question 19

When the neuromodulator protolin is administered to a male blue crab (Callinectes sapidus) at the same time that interneurons that trigger leg waving are being stimulated, the motor output assumes

A) the rhythmic leg waving characteristic of courtship displays.
B) the rhythmic leg waving characteristic of backwards swimming.
C) the posture associated with sideways walking.
D) the posture associated with spread of the front claws.

Question 20

It is the job of an animal's sensory system to

A) be especially sensitive at the low end of a stimulus range.
B) be selective and transmit only biologically relevant stimuli.
C) store presently irrelevant stimuli for later processing.
D) transmit all available information.

Question 21

Cockroaches run when exposed to a gust of wind from a predator, yet they ignore the wind that they create themselves when they walk. Plummer and Camhi (1981) were able to demonstrate that this happens because

A) cockroaches generate a wind speed of only 12 mm per second when they walk, but a predator produces a wind speed of 100 mm per second when it strikes.
B) it is not actually the wind generated by the predator that is the critical stimulus, but a visual stimulus, such as a looming shadow, that generates the escape response.
C) the absolute velocity, rather than the relative velocity, of the wind is the critical factor in inducing running behavior.
D) when presented with winds of the same peak velocity, cockroaches ran more frequently when exposed to winds of higher acceleration.

Question 22

Binaural comparison contributes to locating the source of a sound by allowing an organism to compare differences in

A) sound intensity.
B) the onset and offset of a sound.
C) phase differences in a sound.
D) each of the above variables.

Question 23

When the wavelength of a sound equals the head width of an animal, the sound is

A) artificially increased in pitch, making the sound easier to localize.
B) degraded by bone and soft tissue, making the sound more difficult to localize.
C) difficult to localize, because the phase of the sound wave is the same in each ear.
D) easy to localize, because the phase of the sound wave is the same in each ear.

Question 24

Roeder (1967) determined that the noctuid moth has two auditory receptors, A1 and A2, for each of its two ears. Which of the following statements about the receptors is TRUE?

A) The A1 receptors are approximately 10 times more sensitive than the A2 receptors and begin to respond when a predatory bat is still some distance away.
B) The A1 receptors are on the left side and the A2 receptors are on the right side of the moth's body, making determination of a predatory bat's direction possible.
C) The A1 receptors are responsible for coding differences in a predatory bat's distance from the moth; the A2 receptors are responsible for coding differences in direction.
D) The A1 receptors serve as a general early warning system; the A2 receptors are primarily responsible for directing fine control of directional movement for effective evasive maneuvers.

Question 25

What behavior is a noctuid moth most likely to display when its A1 auditory receptor cell is stimulated?

A) fly upward
B) freeze in place
C) perform a series of lops, rolls, and dives
D) turn and fly directly away

Question 26

A barn owl (Tyto alba) can locate the source of the sounds of its prey within 1º or 2º in both the horizontal and vertical planes. This is largely due to

A) time differences in the arrival of sound to each ear.
B) differences in a sound's intensity between the two ears.
C) the fact that the owl's ear canals are placed asymmetrically on either side of its head.
D) all of the above.

Question 27

The anatomical feature of the barn owl (Tyto alba) that has been demonstrated both to amplify sound and make the ear more sensitive to sound from certain directions is its

A) A2 cells.
B) facial ruff.
C) highly mobile head.
D) mobility of the ears.

Question 28

Which of the following statements regarding auditory and visual input in the barn owl is TRUE?

A) Internal auditory maps can be formed without visual input, but the precision of the map is increased by visual experience.
B) Owls' eyes are fixed in their heads, thus they are essentially blind and rely almost entirely on their hearing to hunt.
C) When information from the auditory map conflicts with visual input, owls trust their auditory system.
D) While both hearing and sight are very keen, the barn owl relies most heavily on its sense of smell.

Question 29

Habituation of the gill-withdrawal reflex in Aplysia has been shown to be the result of

A) a decrease in the strength of response from the motor neuron.
B) less neurotransmitter being released into the synapse.
C) muscle fatigue.
D) the sensory neuron producing weaker action potentials to repeated stimulation.

Question 30

Sensitization of the gill-withdrawal reflex in Aplysia, in contrast to habituation, has been shown to require

A) facilitating interneurons, which release serotonin onto the axon terminal of the sensory neuron.
B) motor neurons, which generate stronger than normal action potentials.
C) sensory neurons, which allow less Ca++ into the cell.
D) synaptic vesicles, which compensate for repeated stimulation by hyperpolarizing the sensory neuron.

Question 31

A process that results in the elevation of response of a postsynaptic neuron for minutes or hours is called

A) long-term depression (LTD).
B) long-term potentiation (LTP).
C) neurogenesis.
D) synaptic remodeling.

Question 32

A process that results in structural changes in synapses, such as changes in the size, shape, and number of dendritic spines and in glial cells, which produce growth factors is called

A) long-term depression (LTD).
B) long-term potentiation (LTP).
C) neurogenesis.
D) synaptic remodeling.

Question 33

Nottebohm (1965), in his study of the neurology of birdsong, made use of the fact that new neurons will incorporate chemical markers when they make DNA in preparation for cell division, but that old neurons do not, because they do not synthesize DNA. This information allowed him to demonstrate that

A) the increase in RA volume was due to changes in neuron size, but that changes in the HVC was due to appearance of new neurons.
B) the two song centers, the HVC and the RA, were interconnected, but only during initial song learning.
C) the volume of two song centers in the brains of male zebra finches, the HVC and the RA, increase and decrease seasonally.
D) there is actually little relationship between the addition of new neurons and song learning in male zebra finches.

Question 34

There is a correlation between the timing of the addition of new neurons to the affected song center and the song learning sequence in male zebra finches. This leads us to conclude that

A) both of these events must be caused by some outside variable.
B) song learning causes the addition of new neurons.
C) the nature of the relationship needs to be tested experimentally.
D) the new neurons cause song learning to take place.

Question 35

Dupret and colleagues (2007), studying rats in a water maze test that makes use of a hidden platform, have found that spatial learning depends on

A) the production of new neurons in the hippocampus.
B) the selective death of some new neurons in the hippocampus.
C) the selective survival of new neurons in the hippocampus.
D) all of the above.

Question 36

While Newman (1999) originally suggested that mammalian social behaviors, such as aggression, sexual behavior, social recognition, and response to stress, is controlled by six regions, or nodes, of the brain, Goodson (2005) proposed that this social network can be found in the brain of all vertebrates. Which of the following statements regarding the social network is TRUE?

A) A particular observed social behavior depends on the pattern of response across all six regions.
B) Areas 1, 3, and 4 are most active in males; areas 2, 5, and 6 are most active in females.
C) Each of the six brain regions is associated with a specific set of social behaviors.
D) The regions can interact to form a network because the information flow among them is unidirectional.

Question 37

Goodson and colleagues (2005) hypothesized that the pattern of activity across the brain regions forming the social behavior network would vary in species of birds that differ in the typical size of their social group. When two species of waxbills were exposed to a same-sex conspecific, activity in the brain regions involved in social stress and dominance related behaviors

A) failed to support Goodson's hypothesis.
B) was higher in the territorial waxbill species than in the more gregarious waxbill species.
C) was lower in the territorial waxbill species than in the more gregarious waxbill species.
D) was surprisingly unaffected by the social interaction.

Question 38

Muscles are often described as biological transducers. This means that they

A) are concerned with input to the central nervous system.
B) are controlled primarily by afferent neurons.
C) convert environmental energy into the electrochemical signals of the nervous system.
D) convert the signals of the nervous system into body movements.

Question 39

A particular motor movement, or behavior, might ultimately be controlled and coordinated by

A) motor commands.
B) sensory reflexes.
C) the central pattern generator.
D) any one of the above.

Question 40

There are two general hypotheses for the neural basis of rhythmic behavior such as locust flight, the peripheral-control hypothesis and the central pattern generator hypothesis. The removal of sensory input from mechanoreceptors on the wings of locusts to their central nervous system resulted in

A) support for the central pattern generator hypothesis.
B) support for the peripheral-control hypothesis.
C) the species typical flight pattern, but with a significantly increased frequency of wing beats.
D) the species typical flight pattern, as long as their wing and thoracic muscles remained intact.