3) IT INFLUENCES THE DEVELOPMENT OF ADULT SEX CHARACTERISTICS.
Estrogen is the primary female sex hormone. They promote the development of primary and secondary sex characteristics in females. These characteristics include breasts, uterus and vagina at puberty.
They are also involved in regulation of the menstrual cycle. Estrogen causes ovum (egg) maturation and follicle development, development of endometrium (lining of a uterus) during the proliferation phase of the uterine cycle.