Answer to Question 1
ANS: This is the universal idea that nuclear members of the family do not have sexual relationships with one another (parent-child and siblings)
Answer to Question 2
ANS: Benefits include the creation of fairly stable relationships between men and women that regulate sexual mating and reproduction, a mechanism for regulating the sexual division of labor, and the creation of a set of family relationships that provide for the material, educational, and emotional needs of children for a long period of time.