Biology Forums - Study Force

There are two types of photoreceptors in the retina; they are the _____ and _____.
Answer: Rods; Cones

The _____ are responsible for seeing black and white during relatively low-light conditions.
Answer: Rods

The _____ are responsible for seeing colors.
Answer: Cones

The three types of cones are termed the _____, because of the length of wavelengths of light they can absorb.
Answer: S (short), M (medium) and L (long)

Blue light is absorbed by the _____ cones and green light is absorbed by the _____ cones; red light is absorbed by the _____ cones.
Answer: S;M;L

The most common reason for color blindness is improper development of one of the _____, however, there are other reasons.
Answer: Cones

The genes that produce the red and green photopigments are located on the _____ and are _____.
Answer: X chromosome; recessive

The most common type of color blindness is red-green color blindness. This condition is generally caused by a genetic defect in the photopigments of red or green cones. It is a recessive disorder involving the X chromosome. It is most commonly seen in __________, because they have __________ chromosome(s).
Answer: males; only one X

Blue color blindness also exits, but the gene is not on the X chromosome. It is located on one of the autosomes; autosomes are all the chromosomes except the X and Y chromosomes. This condition is __________ .
Answer: equally seen in both male and female

The common test for color blindness uses the _____.
Answer: Ishihara chart