<prompt> First sign of puberty in boys isTestes enlargementBreast enlargementPenis enlargementScrotum enlargement  <response>: Testes enlargement 68-G 498-Ghai 7thFirst sign of sexual maturation is enlargement of breast in female and testes in boy 68-G Pubertal onset before he age of 8 years in girl and 9.5 years in boys is suggestive of precocious pubertyAdolescentWHOUN definitionsStages of adolescence Adolescent 10-19 years Youth 15-24 years Young people 10-24 years Early adolescence 9-13 years Mid adolescence 14-15 years Late adolescence 16-19 years Menarche usually occurs at breast and pubic hairs stage 4 