Heartbeat, digestion, respiration, and elimination of wastes are carried out by organ systems close to the central axis. These functions, close to the center of the body, operate or are ready to operate when the child is born. What principle of development does this represent?

Which of the following factors is not related to a person's weight?

a. Exposure to food advertisements b. Sedentary lifestyle c. Ethnicity d. All of these are related to weight.

In a research study, the consent of a parent or guardian is usually required

a. for adolescents 12 and under. b. for emerging adults who still live with their parents. c. for adolescents 18 and under. d. only if the study is conducted in a public school.