module 6.1

Question 1

The blind spot in each eye is blind because:

everyone has nerve damage.
the fluid in the eye becomes crystallized there.
amacrine cells are tangled there.
there are no receptors there.

Answer 1

there are no receptors there.

Question 2

The most common form of color vision deficiency is due to:

poor eyesight.
malformation of area V4 in the brain.
complete absence of one of the types of cones.
long- and medium-wavelength cones making the same photopigment.

Answer 2

long- and medium-wavelength cones making the same photopigment.

Question 3

In the human retina, messages go from receptors at the back of the eye to ____.

retina cells
bipolar cells
ganglion cells
spiny cells

Answer 3

bipolar cells

Question 4

More than a century ago, researchers had evidence that the human retina contained three kinds of color-sensitive receptors. What was the basis of their evidence?

observations of negative after-images
studies of how people adapt to various degrees of light or darkness
chemical measurements on the receptors themselves
experiments on mixing colors of light together

Answer 4

experiments on mixing colors of light together

Question 5

Color constancy is the ability to:

perceive all wavelengths as the same color.
see color, even in very faint light.
differentiate among many colors and hues.
recognize the color of an object despite changes in lighting.

Answer 5

recognize the color of an object despite changes in lighting.

Question 6

According to the trichromatic theory of color vision:

there are only three rods and three cones in each eye.
there are only three colors of light in the worl
rods are important for perception of light colors.
our perception of color depends on the relative activity of three types of cones.

Answer 6

our perception of color depends on the relative activity of three types of cones.

Question 7

Light enters the eye through an opening in the center of the iris called the:

retina
cornea
pupil.
macula

Answer 7

pupil.

Question 8

The optic nerve is composed of axons from which kind of cell?

rods and cones
bipolar cells
horizontal cells
ganglion cells

Answer 8

ganglion cells

Question 9

Ganglion cells near the fovea in humans and other primates are called ____ ganglion cells.

midget
giant
reticulated
cone-shaped

Answer 9

midget

Question 10

Light energy converts 11-cis-retinal to:

opsins.
unstable proteins.
all-trans-retinal.
sodium.

Answer 10

all-trans-retinal.

Question 11

Color and brightness constancy are best explained by the ____ theory of color vision.

trichromatic
opponent-process
retinex
constancy

Answer 11

retinex

Question 12

Light from the right half of the world strikes what part of the retina?

the left half
the right half
the whole retina equally
It depends of the wavelength.

Answer 12

the left half

Question 13

In comparison to cones, rods:

are more sensitive to detail.
are more sensitive to dim light.
reach their peak firing levels slowly.

Answer 13

are more sensitive to dim light.

Question 14

If you want to see something in fine detail, you should focus the light on which part of your retina?

the optic nerve
the fovea
an area containing mostly rods
the cornea

Answer 14

the fovea

Question 15

Various types of ____ cells refine the input to ganglion cells, enabling them to respond specifically to shapes, movement, or other visual features.

receptors
geniculate cells
amacrine cells
optic nerves

Answer 15

amacrine cells

Question 16

In what order does visual information pass through the retina?

receptor cells, ganglion cells, bipolar cells
ganglion cells, bipolar cells, receptor cells
receptor cells, bipolar cells, ganglion cells
bipolar cells, receptor cells, ganglion cells

Answer 16

receptor cells, bipolar cells, ganglion cells

Question 17

Night-active species are more likely than day-active species to have:

better peripheral vision.
larger blind spots.
a greater rod to cone ratio.
a greater cone to rod ratio.

Answer 17

a greater rod to cone ratio.

Question 18

At the level of rods and cones, the ____ theory seems to fit best, while at the level of the bipolar cells, the ____ theory seems to fit best.

opponent process; volley
volley; trichromatic
opponent process; trichromatic
trichromatic; opponent process

Answer 18

trichromatic; opponent process

Question 19

Because blood vessels and ganglion cell axons are almost absent near the ____, it has nearly unimpeded vision.

optic nerve
fovea
area containing mostly rods
cornea

Answer 19

fovea

Question 20

If you wanted to see a faint star at night, you should:

stare straight at it.
look slightly to one side.
look at a mirror’s reflection of it.
wait until daytime.

Answer 20

look slightly to one side.

Question 21

Rods are to ____ as cones are to ____.

the periphery; the fovea
red; blue
vertebrates; invertebrates
reading text; reading road signs

Answer 21

the periphery; the fovea

Question 22

According to the law of specific nerve energies, the brain tells the difference between one sensory modality and another by:

which neurotransmitter is release
which neurons are active.
the velocity of the action potentials.
the amplitude of the action potentials

Answer 22

which neurons are active.

Question 23

____ are chemicals that release energy when struck by light.

Phototransmitters
Photosins
Photopigments
Photoions

Answer 23

Photopigments

Question 24

What is perceived when all types of cones are simultaneously and equally active?

red
green
white
yellow

Answer 24

white

Question 25

According to the retinex theory, we perceive color by:

the relative activity of three kinds of cones.
contrasting the activity in one area of the visual field with that of the others.
a red vs. green system and a yellow vs. blue system.
detecting the velocity of action potentials from the eye.

Answer 25

contrasting the activity in one area of the visual field with that of the others.

Question 26

Light is focused as it enters through which of the following structures?

lens only
cornea only
lens and cornea
pupil

Answer 26

lens and cornea

Question 27

Which receptors are responsible for the perception of color?

cones
rods
both rods and cones
horizontal and amacrine cells

Answer 27

cones

Question 28

Why does the fovea provide the clearest, most detailed visual information?

It is closest to the pupil.
It surrounds the optic nerve.
Receptors are tightly packed there.
There are many blood vessels for supplying energy.

Answer 28

Receptors are tightly packed there.

Question 29

After you stare at a bright green object for a minute and look away, you see red. Which theory attempts to explain this finding?

Young-Helmholtz theory
trichromatic theory
opponent-process theory
color-constancy theory

Answer 29

opponent-process theory

Question 30

The bipolar cells send their messages to ____, located closer to the center of the eye.

spiny cells
cornea cells
bipolar cells
ganglion cells

Answer 30

ganglion cells

Question 31

Difficulty distinguishing between ____ and ____ is the most common form of color vision deficiency.

blue; yellow
green; blue
red; green
red; blue

Answer 31

red; green

Question 32

What are the two kinds of receptors in the retina?

bipolar and ganglion cells
ganglion and rods
rods and cones
amacrine and horizontal

Answer 32

rods and cones

Question 33

Why are men more likely to experience color vision deficiency than women?

Women have a greater number of cones.
Men don’t have as much experience matching colors.
It is a sex-linked genetic disorder.
Testosterone in males affects the activity of the cones.

Answer 33

It is a sex-linked genetic disorder.

Question 34

Light from above our head strikes the:

left side of the retina
right side of the retina
top half of the retina
bottom half of the retina

Answer 34

bottom half of the retina

Question 35

Based on the relative distribution of the three kinds of cones in the retina, which color of road sign would be most difficult to see from a distance?

blue
red
yellow
white

Answer 35

blue