[Solved] Ionizing radiation both causes cancer and can be used to treat cancer. Precocious Puberty: The onset of puberty occurring at an unusually early age, often defined as before 8 in girls and before 9 in boys. Sexual Activity: Behaviors associated with the expression of sexuality and erotic desire, including intercourse and other forms of physical intimacy between individuals. Adolescence: The transitional stage of physical and psychological development that generally occurs during the period from puberty to legal adulthood. Homosexual Orientation: A sexual orientation characterized by a romantic or sexual attraction to individuals of the same sex.