Which of the following are true of color vision in New World monkeys?
A) Both male and female howler monkeys have trichromatic vision.
B) Many species maintain multiple alleles of the red/green opsin gene in the population.
C) Random X-inactivation would allow a female monkey heterozygous for two opsin alleles with differing spectral sensitivities to distinguish red and green.
D) A shared regulatory region likely ensures that only one opsin gene (red or green) is expressed in each cone cell in howler monkeys.
E) All of the above

Question

Quizplus · Accepted Answer

Interestingly, female New World monkeys can take advantage of distinct alleles of an X-linked opsin gene: since one X is inactivated at random in each cell, each cone cell will express only one of the alleles, allowing trichromatic vision. In howler monkeys, this gene has duplicated, but a locus control region (LCR) likely ensures that only one of the two genes is expressed randomly in each cone cell, permitting trichromatic vision in both males and females.

Which of the Following Are True of Color Vision in New