MC. Which of the following is not a trait used to distinguish the order primates from other mammals?

A. Grasping hands and feet

B. Ability to walk upright

C. Fingernails and sensitive fingertips

D. Eyes are used together stereoscopically

MC. Gorillas live in male-dominated groups, with a single adult male and several females. Adult male gorillas compete to control these groups. Chimpanzees live in large, mixed social groups. Adaptively speaking, we might expect _____ to have larger genitals, because _____.

A. chimpanzees; they have access to more sexual partners

B. gorillas; they have access to more sexual partners

C. chimpanzees; they are more likely to use their genitals as part of sexual competition

D. gorillas; they are more likely to use their genitals as part of sexual competition