In Western societies, adolescence typically spans the period from ____ to ____ years of age

The muscles, blood, and the excretory system develop from which of the following layers of cells present in the embryo?

a. ectoderm b. mesoderm c. endoderm d. zygoderm

Twenty years ago, Frank was diagnosed as suffering from schizophrenia. Today he continues to suffer the symptoms of this disorder. Frank's diagnosis places his family members at higher risk for

a) alcoholism. b) anxiety disorders. c) major depression. d) schizotypal personality disorder.