1. The central idea of the passage is primarily concerned with
A. how to determine if a person is colorblind.
B. research being conducted about colorblindness.
C. how people who are colorblind perceive color.
D. the genetic and physiological causes of colorblindness.
2. Which choice provides the best support for the answer to the previous question?
A. Lines 1-3 ("About eight … condition")
B. Lines 15-18 ("People with … retinas")
C. Lines 24-26 ("The cones … absorb most")
D. Lines 48-50 ("A person … pigment")
3. In paragraph 6, the author includes details about X chromosomes in order to
A. give examples of other traits inherited from mothers.
B. explain why more men than women are colorblind.
C. illustrate how genes affect vision and colorblindness.
D. contrast colorblindness with other genetic disorders.
4. Based on the passage, which choice best describes what causes red and green to be the two colors that a colorblind person often cannot perceive?
A. A colorblind person is missing both red and green cones on the back of the retinas.
B. Because blue wavelengths are brighter, they overpower both red and green wavelengths.
C. Because red and green absorption ranges overlap greatly, the colorblind person's brain has trouble interpreting the difference between those two colors.
D. Red and green are on opposite sides of the color wheel, so their absorption ranges are at the farthest, opposite ends of the visible light spectrum.
5. Which choice would provide the most support for the author's line of reasoning in paragraph 1?
A. Details about other types of colorblindness
B. A more detailed explanation of the light spectrum
C. A list of other genetic disorders that affect men
D. Information about how colorblindness is diagnosed