1. Of all the developments that take place during the second decade of life, the only one that is truly inevitable is: A. physical maturation. B. an identity crisis. C. rebellion against one's parents. D. the first experience of romantic love. 2. The average girl in the United States reaches _________, the time of her first menstrual period, sometime between the ages of 12 and 13. A. spermarche B. menarche C. puberty D. adrenarche 3. The physical transformation from child to adult is called: A. puberty. B. early adolescence. C. middle adolescence. D. late adolescence. 4. The term puberty refers to the period during which: A. an individual is between the ages of 12 and 15. B. an individual's endocrine system creates new hormones. C. an individual becomes capable of sexual reproduction. D. an individual stops growing. 5. According to the textbook, puberty involves all of the following except A. development of the primary sex characteristics. B. changes in distribution of fat and muscle in the body. C. development of secondary sex characteristics. D. increases in intellectual functioning 6. Professor Radon is studying the _________ system, which produces, circulates, and regulates levels of hormones in the body. A. adrenal B. circulatory C. respiratory D. endocrine