Approximately what percent of adolescents are liaisons?

Defective color vision is more common among males than females because

a. males have fewer cones than females. b. genes for photopigments are carried on the Y chromosome. c. as a result of higher estrogen levels, females produce more rhodopsin than males. d. genes for photopigments are carried on the X chromosome. e. as a result of lower estrogen levels, males produce more rhodopsin than females.

Research on toddler day care has found that __________________

a. all toddler day care is beneficial to children's development b. parental leave policies and day care are unrelated c. all toddler day care is harmful to children's development d. day care should be staffed by people with credentials who care about young children