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प्रश्न
The diagram given below is that of a developing human foetus. Study the diagram and then answer the questions that follow:
(i) Label the parts numbered 1 to 3 in the diagram.
(ii) Mention any two functions of the part labelled 2 in the diagram.
(iii) Explain the significance of the part numbered 3 in the diagram.
(iv) Define the term ‘Gestation’. What is the normal gestational period of the developing human embryo?
(v) Mention the sex chromosomes in a male and female embryo.
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उत्तर
(i)
- Umbilical cord
- Placenta
- Amniotic fluid
(ii) Functions of placenta:
- It allows the diffusion of oxygen, nutrients and immune products from the mother to the foetus.
- It allows the diffusion of waste material generated by the foetus to the mother to be excreted.
(iii)
- The amniotic fluid prevents the foetus from injury and shocks.
- It allows the foetus some amount of movement.
- It prevents the amnion from sticking to the foetus.
- It maintains an even pressure all around the foetus.
(iv) The time period required for the development of the foetus inside the uterus is called gestation. The normal gestation period in humans is 280 days (9 months).
(v) Male sex chromosomes: One ‘X’ chromosome and one ‘Y’ chromosome (XY) Female sex chromosomes: Two ‘X’ chromosomes (XX)
APPEARS IN
संबंधित प्रश्न
Describe placenta structure.
Suggest three contraceptive methods to control the size of human population, which is essential for the health and prosperity of a country. State the basic principle involved in each.
When a fertilised egg E formed in the oviduct of a human female divides repeatedly to form an embryo, the embryo gets implanted in the thick and soft lining of the uterus. After this a disc-like special tissue T develops between the uterus wall and embryo through which all the requirements of the developing embryo (and foetus) are met from the mother's body, The embryo is connected to the tissue T through a string like structure S.
(a) What is the other name of fertilised egg cell E?
(b) What is the name of tissue T?
(c) Name the string-like structure S.
(d) Name two substances which pass from mother's blood to embryo through tissue T and, one type of substance which passes from embryo to mother's blood.
(e) What happens to S when the baby is born? Why?
“Gender of child is determined by the male partner of couple”. Draw a diagram explaining the above statement.
Diagram shows the reproductive system of female human beings:
(i) Name the parts numbered 1 to 14.
(ii) Normally, after how many days does an ovary release an egg?
(iii) Where are the sperms released during coitus?
(iv) What is the role of sperms after their ejaculation in vagina?
(v) What is the function of the organ numbered 5?
(vi) What is the gestation period in human?
Name the following:
Two accessory glands in the male reproductive system.
Define the following:
Parthenogenesis
Choose the Odd One Out:
Mention any two changes that are common to both boys and girls in early teenage years.
During adolescence, reproductive phase starts and ______.
