(a) List three different categories of contraception methods. (b) Why has Government of India prohibited prenatal sex determination by law? State its benefits in the long run. (c) Unsafe sexual act can lead to various infections. Name two bacterial and two viral infections caused due to unsafe sex.

Q: (a) List three different categories of contraception methods. (b) Why has Government of India prohibited prenatal sex determination by law? State its benefits in the long run. (c) Unsafe sexual act can lead to various infections. Name two bacterial and two viral infections caused due to unsafe sex.

(a) **Functions of Female Reproductive Organs**: * **(i) Ovary**: It produces the female germ-cells (eggs or ova) and secretes female sex hormones such as estrogen and progesterone. * **(ii) Oviduct (Fallopian Tube)**: It carries the egg from the ovary to the uterus and serves as the site where fertilization (fusion of sperm and egg) takes place. (b) **Changes in the Uterus**: * **(i) When it has to receive a zygote**: The uterus prepares itself every month. Its inner lining (endometrium) becomes thick, spongy, and richly supplied with blood vessels to nourish and support the developing embryo after implantation. * **(ii) When no fertilization takes place**: The thick, spongy inner lining of the uterus is no longer needed. It slowly breaks down and is expelled through the vagina along with blood and mucous. This monthly cycle is known as menstruation, which lasts for about 2 to 8 days. (c) **Function of the Placenta**: * The placenta is a specialized disc-like tissue embedded in the uterine wall that connects the embryo to the mother's blood system. * It provides a large surface area for the transfer of glucose and oxygen from the mother to the developing embryo. * It also facilitates the removal of metabolic waste products generated by the embryo by transferring them into the mother's blood.

How do Organisms Reproduce?

Human Female Reproductive System

Official Answer

(a) Functions of Female Reproductive Organs:

(i) Ovary: It produces the female germ-cells (eggs or ova) and secretes female sex hormones such as estrogen and progesterone.
(ii) Oviduct (Fallopian Tube): It carries the egg from the ovary to the uterus and serves as the site where fertilization (fusion of sperm and egg) takes place.

(b) Changes in the Uterus:

(i) When it has to receive a zygote: The uterus prepares itself every month. Its inner lining (endometrium) becomes thick, spongy, and richly supplied with blood vessels to nourish and support the developing embryo after implantation.
(ii) When no fertilization takes place: The thick, spongy inner lining of the uterus is no longer needed. It slowly breaks down and is expelled through the vagina along with blood and mucous. This monthly cycle is known as menstruation, which lasts for about 2 to 8 days.

The placenta is a specialized disc-like tissue embedded in the uterine wall that connects the embryo to the mother's blood system.
It provides a large surface area for the transfer of glucose and oxygen from the mother to the developing embryo.
It also facilitates the removal of metabolic waste products generated by the embryo by transferring them into the mother's blood.

ovaryoviductfertilizationuterusthick and spongy liningmenstruationplacentaglucose and oxygenwaste removal

Marking Scheme

1Functions of ovary (egg production, hormone secretion) and oviduct (egg transport, site of fertilization) (1.5 marks)
2Uterine changes when receiving a zygote (thickening, vascularization) (1 mark)
3Uterine changes when no fertilization occurs (breakdown of lining, menstruation) (1 mark)
4Functions of placenta (supplying glucose/oxygen and removing metabolic wastes) (1.5 marks)

Hint

Recall the roles of the ovary and fallopian tube. Think about how the uterine wall thickens for pregnancy and sheds during menstruation. Describe the placenta as a transport bridge.

Quick Oral Answer

The ovary produces eggs and hormones, while the oviduct is where fertilization occurs. If a zygote is received, the uterus thickens; if not, it sheds its lining during menstruation. The placenta supplies nutrients and oxygen to the fetus and removes waste.

Analysis & Explanation

The female reproductive system is dynamically regulated to support potential pregnancy. The ovaries release an egg monthly, which travels down the oviduct where fertilization occurs. The uterus undergoes cyclic changes: thickening to prepare for a zygote, or shedding (menstruation) if fertilization fails. If fertilization succeeds, the placenta forms to act as a physiological interface, ensuring nutrient/oxygen supply and waste removal for the developing fetus.

Common Mistakes

1Stating that fertilization occurs in the uterus instead of the oviduct.
2Failing to mention the hormonal function of the ovaries.
3Not explaining that the placenta removes waste in addition to supplying nutrients.

Interesting Facts

The placenta is a unique temporary organ; it is the only organ in the human body created, used, and then discarded after its function is complete (during childbirth).

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Frequently Asked Questions

How many marks does this question carry in CBSE Class 10 Science 2020?

This question carries 5 marks in the CBSE Class 10 Science 2020 examination.

Which chapter does this question come from in Science?

This question is from the chapter "How do Organisms Reproduce?" in the CBSE Class 10 Science syllabus.

What topic does this question cover in Science?

This question covers the topic "Human Female Reproductive System" from CBSE Class 10 Science.

What type of question is this in the CBSE Class 10 Science 2020 paper?

This is a Long Answer question from Section C in the CBSE Class 10 Science 2020 paper.