43.  Primary sexual characteristics refers to reproductive organs of males and females, such as, the ovaries and uterus in females, and the testes in males.  Secondary sexual characteristics refers to physical signs of sexual development.  For example, in females, the development of breasts, hips, and menarche, and in males, the development of facial hair, a deepened voice, and spermarche.  All these changes normally happen during puberty.