Answer to Question 1
During early adolescence, parents are often shocked at the extreme changes that occur in their children; children can add 5 or 6 inches in height and gain 10 to 20 pounds in less than a year. Boys may develop a lower voice and a more decidedly adult physique, whereas girls develop breasts and a more female physique. Biological changes take place in virtually every system of the body and include changes in cardiovascular status, energy levels, sexual desire, mood, and personality characteristics (Hamburg, 1986).
Answer to Question 2
Greenwald and Leitenberg (1989) found that among a sample of college students, 17 reported having sibling sexual contact before age 13 . Only a small percentage involved force or threat, and penetration was rare. Research on sexual contact between siblings suggests that it can be psychologically damaging when there is a large difference between the ages of siblings or coercive force is used (Finkelhor, 1980; Rudd & Herzberger, 1999).
Four main models that describe the relationship between ecosystem function and biodiversity.
physical exam
The Number of Children Americans Think Are Ideal
Physical Geography and Environmental Issues