Question

(a) What changes are seen in girls at the time of puberty?
(b) Name the organs which produce ova (or egg cells) in human females.
(c) Draw a labelled diagram of the human female reproductive system. With the help of this diagram, explain the working of human female reproductive system.
(d) Describe the process of fertilisation in humans and development of embryo briefly.

Answer 1

(a) Girls at puberty develop hair in their armpits and around the pubic region. The mammary glands develop and become large. The hips get broadened and extra fat gets deposited on various parts of the body. The ovaries start releasing eggs; the vagina enlarges and menstruation starts.

(b) Ovaries in humans produce ova, which are also known as egg cells.

(c) Ovaries are the primary reproductive organs in females, which produce ovum or egg. Above the ovary lies the oviducts, or fallopian tubes, which are connected to the uterus. The eggs move into the oviduct from the ovaries, where it gets fertilised by a sperm. The fertilised ovum develops into a baby in the uterus. The uterus is connected to the vagina by the cervix. The vagina opens outside the body and receives sperms.



(d) In humans, fertilisation is internal. Sperms are introduced in the vagina by the penis during copulation. The sperms move up through the cervix, enter the uterus and pass into the oviducts. In the oviducts, the egg gets fertilised by one of the sperms. Zygote is formed by the fusion of a sperm and an egg. This zygote divides multiple times to form a hollow ball of the cells called embryo.