Question 1

The ciliary muscles change the shape of the _____, providing about 20% of the eye's focusing power.

Accepted Answer

The ciliary muscles change the shape of the lens, which provides about 20% of the eye's focusing power. The iris controls the size of the pupil, and the cornea is the clear outer layer that covers the front of the eye.

Question 2

The isomerization of a single pigment molecule triggers what is best described as a _____.

Accepted Answer

The isomerization of a single pigment molecule can trigger a chain reaction that involves the activation of multiple pigment molecules in a series, leading to the generation of a nerve impulse. This is a well-known process in vision, where the absorption of light by a single pigment molecule in the retina triggers a chain reaction that leads to the transduction of this information into an electrical signal that is sent to the brain for further processing. Ballistic expansion, hyperactive potential, and hypopolarization wave are not accurate descriptions of this process.

Question 3

Individuals with myopia may have difficulty seeing _____ objects clearly. Often times, they are also referred to as being _____.

Accepted Answer

Myopia is a condition where individuals have difficulty in seeing distant objects clearly. Therefore, the best choice is D, which states that individuals with myopia have difficulty seeing distant objects clearly. They are commonly referred to as nearsighted, which means that they can see objects clearly that are nearby, but objects at a distance appear blurred.

Question 4

The visual pigment molecules are contained in the _____.

Accepted Answer

The outer segments of the visual receptors contain the visual pigment molecules necessary for vision. The inner segments contain the metabolic machinery needed to support the visual pigment molecules. The axons of the rods and cones transmit information from the photoreceptors to the bipolar cells in the retina.

Question 5

Lorelei's mother is 60 years old, and, because of the condition called _____, she has a difficult time bringing near objects into focus.

Accepted Answer

Presbyopia is a condition that occurs with aging, where the eye's lens becomes less flexible, and it becomes more difficult to focus on close objects. Cataracts involve clouding of the eye's lens, diplopia is double vision, and retinitis pigmentosa is a genetic condition that affects the retina.

Question 6

The structure of the eye that provides about 80% of the eye's focusing power is the _____.

Accepted Answer

The cornea is the eye's outermost layer and is the primary structure responsible for focusing most of the light that enters the eye. It provides about 80% of the eye's focusing power, with the lens inside the eye adjusting to fine-tune vision.

Question 7

A retinal condition that destroys the cones in the fovea is _____.

Accepted Answer

Macular degeneration is a retinal condition that causes the progressive death of photoreceptor cells in the macula, a region responsible for central vision. This condition can destroy the cones in the fovea, leading to loss of detail and color vision. Retinitis pigmentosa is a genetic disorder that affects the rods and cones in the retina, causing night blindness and peripheral vision loss. Presbyopia is an age-related condition that affects the ability to focus on close objects. Retinal hypopolarization is not a recognized medical condition.

Question 8

Visible light is between _____ and _____ nm within the electromagnetic spectrum.

Accepted Answer

Visible light ranges from approximately 400 to 700 nanometers (nm) within the electromagnetic spectrum. Option A has too short of a range, Option C has too long of a range, and Option D includes infrared radiation, which is not part of visible light.

Question 9

Our perception of the environment begins with _____.

Accepted Answer

Our perception of the environment begins with the distal stimulus, which refers to any physical object or event in the external world that reflects light, emits sound, or produces other forms of energy that our sensory systems can detect.

Question 10

The episode of "Mythbusters" cited in the textbook demonstrated that dark adaptation was the reason why _____.

Accepted Answer

The "Mythbusters" episode showed that pirates wore eyepatches to maintain their vision in one eye, which would already be adapted to the darkness below deck, when they needed to suddenly go above deck into bright sunlight.

Question 11

A wavelength of 10,000 meters would fall in the _____ range of the electromagnetic spectrum.

Accepted Answer

A wavelength of 10,000 meters would fall in the radio wave range of the electromagnetic spectrum. Radio waves have the longest wavelengths and lowest frequencies, ranging from about 1 millimeter to more than 100 kilometers in length.

Question 12

In the early stages of _____, peripheral rod receptors are destroyed leading to poorer peripheral vision.

Accepted Answer

Retinitis pigmentosa is a genetic disorder that leads to the destruction of peripheral rod receptors in the retina, resulting in poorer peripheral vision. Macular degeneration affects the central vision, while presbyopia is the age-related difficulty in focusing on nearby objects. Retinal hypopolarization is not a recognized medical condition.

Question 13

Nina does a demonstration of "seeing" the blind spot, in which a grid pattern surrounds the black dot that disappears when it falls on the blind spot. What does Nina most likely see in the area where the dot disappears

Accepted Answer

Nina would most likely see a continuation of the grid pattern due to the brain's ability to fill in missing information in the visual field, especially when the surrounding area has a consistent pattern. This phenomenon helps maintain a continuous perception of the environment even when parts of the visual field fall on the blind spot.

Question 14

In _____, the eyeball is too long, resulting in difficulty seeing far objects.

Accepted Answer

Axial myopia occurs when the eyeball is too long, causing light to focus in front of the retina and resulting in difficulty seeing far objects. Refractive myopia, on the other hand, occurs when the cornea or lens is too curved or powerful, causing light to focus in front of the retina. Axial hyperopia occurs when the eyeball is too short, resulting in difficulty seeing close objects. Refractive hyperopia occurs when the cornea or lens is too flat or weak, causing light to focus behind the retina.

Question 15

Which of the following is true about the difference between the rods and the cones

Accepted Answer

There are about 120 million rods in the human eye and about 6 million cones. This is the main difference between the two types of cells. Rods are more sensitive to light and are used for night vision, while cones are responsible for color vision and require higher light levels to function well. Option A is incorrect as it is the opposite of what is true, Option B is incorrect because the fovea has a higher concentration of cones rather than rods, and Option D is incorrect since there are significant differences in function between the two types of cells.

Question 16

The electromagnetic spectrum is a continuum of electromagnetic energy that is produced by _____ and is radiated as _____.

Accepted Answer

The electromagnetic spectrum is produced by electric charges and is radiated as waves.

Question 17

Vera has hyperopia, and tends to get headaches when she reads. This might be because _____.

Accepted Answer

Hyperopia, or farsightedness, often requires the eyes to accommodate to see objects up close clearly. Presbyopia is a related condition that affects the ability to focus on close objects, often due to aging. If Vera has both conditions, she would need to constantly accommodate, which could lead to headaches.

Question 18

The blind spot is located _____.

Accepted Answer

The blind spot is located where the optic nerve leaves the eye. This is because there are no light receptors located at this point, as the nerve fibers take up space instead.

Question 19

_______ reacts to light to start the process of transduction.

Accepted Answer

Retinal is the chromophore found in photoreceptor cells of the eye that reacts to light and leads to the process of transduction. It is a component of visual pigments such as rhodopsin and iodopsin, and changes its conformation upon absorption of light to activate downstream signaling pathways.

Question 20

Jan tries to focus on the tip of her pencil as she brings it closer to her. She feels the strain on her eye as she does this. What she is feeling in her eye is due to the process called _____.

Accepted Answer

Accommodation is the process by which the lens in the eye changes its shape to focus on objects at different distances. As Jan brings her pencil closer to her eye, her lens adjusts to focus on the tip of the pencil, causing muscle strain in her eye.

Quiz 2: The Beginning of the Perceptual Process