How Do Organisms Reproduce

SEXUAL CYCLE IN FEMALES: MENSTRUATION

• Ovulation: The release of an ovum (or egg) from an ovary is called ovulation.

In human females (or girls females (or girls), the ovaries start releasing ovum or egg i.e. the female gamete once every 28 day from the age of puberty.

• Menstrual flow or menstruation: Menstruation is the breakdown and removal of the inner, the thick and soft lining of the uterus along with its blood vessels in the form of vaginal bleeding. Menstruation occurs if an ovum (or egg) released by the ovary of a woman does not get fertilized due to non-availability of sperm at the time of ovulation.

MENARCHE AND MENOPAUSE

Menarche: The first occurrence of menstruation (or periods) at puberty

Menopause: Menopause is the permanent stoppage of menstruation (or periods) in a woman is called menopause. Menopause occurs in women at the age of about 45 to 50 years.

Parthenogenesis is the process of development of an organism from an unfertilized egg, e.g., drones (male honey bees).