Bil 265, Physiology, Fall 2007 - Second Examination - Form
1
1. Which of the
following is characteristic of the human retina's blind spot?
1) Many nerve cells
crossing this area of the retina but few or no rod or cone cells.
2) A high density of
rod cells but not of cone cells.
3)
A high density of cone cells but not of rod cells.
4) A high density of both rod and cone
cells.
Correct Answer is: 1
2. How did
the electroplax organ most likely evolve?
1) as a modification of spinal ganglia.
2) as a modification of
the anterior end of the spinal cord.
3)
as modified muscle tissue.
4)
as a modification of touch receptors on the skin.
Correct Answer is:
3
3. One of the required readings correctly
states: "Like acetylcholine, muscarine contains a quaternary nitrogen
important for action at the anionic site of the receptor." What is most likely about the binding
of muscarine or acetylcholine to muscarinic acetylcholine receptors?
1) The binding is
covalent through one of the four bonds to the quaternary nitrogen.
2) The quaternary
nitrogen of muscarine helps to push more acetylcholine onto the receptor.
3) Muscarine is an
antagonist to acetylcholine binding to the receptor.
4) Muscarine attaches
to a negative charge on the muscarinic acetylcholine receptor.
Correct
Answer is: 4
4. What is the flicker fusion frequency
for Octopus vision? As always, choose the best or most accurate answer. (Hertz
is a unit of frequency, the number of flashes per second, in this case.)
1) 5 KHz
2) 12 KHz
3) 90 KHz
4) 12 Hertz
5) 90 Hertz
Correct
Answer is: 5
5. What is the flicker fusion frequency
for human vision? As always, choose the best or most accurate answer. (Hertz is
a unit of frequency, the number of flashes per second, in this case.)
1) 5 KHz
2) 12 KHz
3) 90 KHz
4) 12 Hertz
5) 90 Hertz
Correct
Answer is: 4
6. Which of the following structures
consists of a "9+2" arrangement of 9 pairs of microtubules
surrounding two central microtubules?
1) a hypercilium
2) an occilium
3) a stereocilium
4) a monocilium
5) a kinocilium
Correct
Answer is: 5
7. Which of the follow best
characteristizes the endolymph in the scala media?
1) high Potassium
concentration and high Sodium concentration, as compared to the interior of
hair cells.
2)
high Sodium concentration and low Potassium concentration, as compared to the
interior of hair cells.
3)
high Sodium concentration and high Potassium concentration, as compared to the
interior of hair cells.
4)
high Potassium concentration and low Sodium concentration, as compared to the
interior of hair cells.
Correct Answer is: 4
8. Which is a distinctive feature of outer hair cells of the
cochlea, as compared to inner hair cells of the cochlea?
1) Inner hair cells
have higher internal Calcium concentrations than do outer hair cells.
2) Outer hair cells
detect rotational movement whereas inner hair cells detect translational
movement
3)
Outer hair cells have active movement of cilia, produced by motor proteins,
whereas inner hair cells are passive.
4)
Outer hair cells detect high frequencies of sound whereas inner hair cells
detect low frequencies of sound.
Correct Answer is: 3
9. Cone cells are receptor cells in the human retina. These cells are called "cone
cells" because one end is tapered nearly to a point. Which direction does the tapered end
point towards?
1)
The vitreous body
2)
The pigmented epithelium
Correct Answer is: 2
10. Which of the following is characteristic of the human fovea?
1) Many nerve cells
crossing this area of the retina but few or no rod or cone cells.
2) A high density of
rod cells but not of cone cells.
3)
A high density of cone cells but not of rod cells.
4) A high density of both rod and cone
cells.
Correct Answer is: 3
11. Fill in
the blanks in this quote from the lecture notes: "Frequency of the sound
is encoded as _____ on auditory nerves.
Intensity of sound is encoded as _____."
1) "the number of
nerve fibers that are sending signals to the brain", "frequency of
action potentials"
2)
"frequency of action potentials", "the number of nerve fibers
that are sending signals to the brain"
Correct Answer is: 2
12. The blind spot on the octopus retina is located on the part
of the retina that:
1)
is closest to the side of head.
2)
is closest to the center of the head.
3)
is closest to the top of the head (up).
4)
is closest to the bottom of the head (down).
5) The octopus retina doesn't have a blind
spot.
Correct Answer is: 5
13. In
actual practice, at minimum, how many photons of wavelength 510 nm must be
absorbed by vision-producing pigment in the human retina, in order that a
single visual receptor cell will produce a receptor potential?
1) 1
2) 8
3) 50
Correct
Answer is: 1
14. What distinguishes the Owlfly's vision
from that of many other arthropods we discussed?
1) The Owlfly can see
particularly well in the ultraviolet.
2)
The Owlfly has a low flicker fusion frequency, as compared to that of humans.
3) The Owlfly has color
vision that senses green, red, and infrared light.
4) The Owlfly has receptor cells that
connect to neurons by electrical synapses, giving the Owlfly a particularly
fast response to changing light conditions.
Correct Answer is: 1
15. Where would you find the "Organ of Corti"?
1) In a mammalian ear
2) In the mammalian
brain
3) In
the mammalian spinal cord
4)
In the human eye
5)
In an invertebrate compound eye
Correct Answer is: 1
16. Peripheral vision in humans is most sensitive to which color
of light?
1)
red light.
2)
yellow-green light.
3)
violet or blue light.
4)
ultraviolet light.
Correct Answer is: 2
17. We discussed an experiment in which the ability of frogs to
see light flashes of very low intensity was tested. Which of the following is most accurate concerning the
relative ability of cooled frogs to see low light as compared to warmer frogs?
1) The cooler frogs are
most sensitive to low light levels.
2)
The warmer frogs are most sensitive to low light levels.
3) Temperature of the
frogs wasn't related to how sensitive the frogs were to low light.
Correct
Answer is: 1 (Not covered in class)
18. In
actual practice, at minimum, how many photons of wavelength 510 nm must be
absorbed by vision-producing pigment in the human retina, in order that the
person would actually see the flash?
1)
1
2) 8
3) 50
Correct
Answer is: 2
19. Which of the following most likely
describes the potassium Nerst potential across the membranes of cilia of hair
cells?
1)
The potassium Nernst potential across the membranes of the cilia is zero.
2) The potassium Nernst
potential across the membranes of the cilia is positive inside the cell.
3) The potassium Nernst
potential across the membranes of the cilia is negative inside the cell.
Correct
Answer is: 2
20. Curare is most likely to interfere
with:
1)
beating of the heart.
2)
control of autonomic stimulation by the brain stem.
3) contraction of voluntary skeletal
muscles.
4)
hearing, by paralysis of cilia on hair cells.
Correct Answer is: 3
21. LSD is most likely to affect synapses that use which of the
following as neurotransmitters?
1)
glycine.
2)
acetylcholine.
3)
ATP.
4)
serotonin.
5)
glutamate.
Correct Answer is: 4
22. How did
Hecht et. al. measure the attenuation of light as it passes through the human
cornea, lens, and vitreous and the light that fails to be absorbed by pigment
in receptor cells?
1)
They calculated light attenuation from known optical properties of proteins in
the eye.
2)
By fitting data to a mathematical model.
3)
By inserting a tiny fiber-optics probe into the retina.
4) By measuring the
light entering the eye and the light reflected from the retina.
Correct
Answer is: 2
23. Which of the following is an agonist of
the Nicotinic Acetylcholine receptor?
1)
Nicotine.
2)
Curare.
3)
Muscarine.
4)
Atropine.
5)
LSD.
Correct Answer is: 1
24. A
receptive field of the human retina is best defined as?
1) A group of receptor
cells that work together as a unit.
2)
The receptive field is another name for all of the retinal surface except the
blind spot.
3)
The receptive field is another name for the region of the retina called the
fovea.
4) The
area on the retina covered by whatever sized image spot we choose to show a
subject.
Correct Answer is: 1
25. TRUE OR
FALSE: For hearing in the human
ear, mechanical vibrations bend the kinoocilia. The kinocilia are connected to the shorter stereocilia,
which bend in response, thus opening mechanically gated ion channels on cell
membranes.
1)
TRUE
2) FALSE
Correct Answer is: 1 (Considerable evidence exists that the kinocilia
on human hair cells degenerate, leaving only stereocilia. Thus this question is misleading -
Everyone was given credit on the examination.)
26. What is the function of the sacculus?
1) part of the
posterior end of the lateral line. Used by fish to detect sound.
2) detection of
rotational acceleration
3)
primarily gathers sensory information about linear movement in the vertical
plane
4)
used for communication in weakly electric fish.
Correct Answer is: 3
27. The flavor enhancer MSG is most likely to affect synapses
that use which of the following as neurotransmitters?
1) glycine.
2) acetylcholine.
3) ATP.
4) serotonin.
5) glutamate.
Correct
Answer is: 5
28. Alpha-bungarotoxin is made by one or
more species of the following:
1)
snake.
2)
jellyfish.
3)
mushroom.
4)
a flowering plant.
5)
frog.
Correct Answer is: 1
29. A
spingid moth, "Deilephila elpenor", has three different types of
photoreceptors, each of which is sensitive to one range of colors. Which of the following best describes
the three ranges of color that the photoreceptors are sensitive to?
1) red, green, violet.
2) red, violet,
ultraviolet.
3)
infrared, red, green.
4)
green, violet, ultraviolet.
Correct Answer is: 4
30. Regular sunglasses reduce the intensity of light passing
through them by a constant fraction.
Typical sunglasses might reduce the intensity of light by 90%, letting
only 10% pass through. Suppose that you have been given a pair of regular
sunglasses. How would these glasses help or hurt contrast discrimination, the
ability to distinguish different intensities of light in the environment?
1) You would be able to
better distinguish various shades of gray from each other in very bright light,
compared with using no glasses at all.
2)
The glasses would not improve or reduce your ability to distinguish shades of
gray from each other, compared with using no glasses at all.
3) You would be able to
better distinguish various shades of gray from each other in very dim light,
compared with using no glasses at all.
Correct Answer is: 1
31. Regular sunglasses reduce the intensity of light passing
through them by a constant fraction.
Typical sunglasses might reduce the intensity of light by 90%, letting
only 10% pass through. Suppose that you have been given a pair of a new type of
sunglasses, which amplify light by five times. Thus the intensity of light reaching your eyes would be five
times the intensity in the environment.
How would these glasses help or hurt contrast discrimination, the
ability to distinguish different intensities of light in the environment?
1) You would be able to
better distinguish various shades of gray from each other in very bright light,
compared with using no glasses at all.
2)
The glasses would not improve or reduce your ability to distinguish shades of
gray from each other, compared with using no glasses at all.
3) You would be able to
better distinguish various shades of gray from each other in very dim light,
compared with using no glasses at all.
Correct Answer is: 3
32. TRUE OR FALSE:
The Weber-Fechner law applies to vision at the very lowest light levels,
just above the threshold for human vision in low light.
1) TRUE
2) FALSE
Correct
Answer is: 2
33. Why has evolution favored insect vision
that is sensitive to ultraviolet light?
1) Ultraviolet light has less energy than
light visible to humans. The lower energy ultraviolet light does less damage to
the smaller number of receptor pigment molecules in insects.
2) The
"light-piping" in insect ommatidia gives the highest resolution of
objects is the wavelength of light is low.
3)
Optical diffraction is less with ultraviolet light.
4) Snell's law refraction causes less
spreading of light at short wavelengths of light.
5) Only a few invertebrates, such as squid
and octopus, can detect ultraviolet light with their eyes. No insect has eyes
that can detect ultraviolet light.
Correct Answer is: 3
34. Why did Hecht and coworkers fixate the subject's eyes on a
light of deep red color (approximately 700 nm)?
1) Optical diffraction
will be minimized with dark red light.
2)
Psychologists have shown that deep red light relaxes human subjects.
3) The wavelength of
deep red light is very far from the peak of the rod cell's absorption spectrum.
4) Red light has low
energy and won't damage the cone cells of the eye.
5) Rod cells absorb deep red light better
than any other wavelength.
Correct Answer is: 3
35. Rectifying properties of synapses are most closely
associated with:
1)
Slow chemical synapses.
2)
Fast chemical synapses.
3)
Electrical synapses
Correct Answer is: 3
36. In actual practice, at minimum, how many photons of
wavelength 510 nm must enter the cornea of a single human eye, in order that
the person would actually see the flash?
1) 1
2)
8
3) 50
Correct
Answer is: 3
37. Gap junctions would be expected to be
most closely associated with:
1)
postsynaptic membranes of slow chemical synapses
2) postsynaptic membranes of fast chemical
synapses
3)
sodium channels on a nerve axon.
4)
electrical synapses
Correct Answer is: 4
38. A Martian lands in Coconut Grove on a Thursday night. Anxious to follow up your studies in
physiology, you repeat the test for the position of the blind spot as we did in
class. The distance between the
"+" symbol that one stares at and the black dot that will disappear
when it is imaged onto the blind spot is 5.0 cm., just as on the yellow sheets
given out in class. You note that
the Martian has to bring the sheet of paper very close to her eye in order to
get the black dot to disappear.
The dot disappears when the sheet of paper is exactly 5.0 cm. from the
center of the lens in the Martian's eye.
At what angle from the fovea is the Martian's blind spot?
1) 15 degrees
2) 20 degrees
3) 30 degrees
4) 45 degrees
5) 60 degrees
Correct
Answer is: 4
39. TRUE OR FALSE: Retinal (retinaldehyde) changes from
the trans to the cis configuration when a photon of light is absorbed.
1) TRUE
2) FALSE
Correct
Answer is: 2
40. Where would you most likely find the
stapes?
1)
in the electroplax organ
2)
as organelles in retinular cells.
3)
inside a human cochlea
4)
in the lateral line of a frog
5)
attached to the oval window
Correct Answer is: 5