CBSE – 8th Standard Science

CBSE - 8th Standard Science

Question Bank – Chapter 10 – Reaching the age of adolescence

Chapter 10

Reaching the age of Adolescence


Q.1 Define adolescence.

Ans. The period of life, when the body undergoes changes, leading to reproductive maturity, is called adolescence.


Q2. Why adolescence is important?

Ans. The most important change which marks puberty is that boys and girls become capable of reproduction. Puberty ends when an adolescent reaches reproductive maturity.



Q 3. What is menstrual Cycle? Explain. 

Ans. Menstrual cycle is controlled by hormones. The cycle includes the maturation of the egg, its release, thickening of uterine wall and its breakdown if pregnancy does not occur.


Q4. What are main changes at puberty?

Ans. Change in voice, increase in height, changes in body shape, growth of sex organs and mental maturity are the main changes at puberty.


Q5. What controls the changes at adolescent period?

Ans. The changes which occur at adolescence are controlled by hormones. Hormones are chemical substances. These are secretions from endocrine glands.


Q6. Which one is Master gland?

Ans. Pituitary gland is the master gland,the production of all hormones is under the control of another hormone secreted from pituitary gland, this endocrine gland is attached to the brain.


Q7. Name some Endocrine glands found in human body?

Ans. Apart from the pituitary, the testes and the ovaries ,thyroid, pancreas and adrenals are main endocrine glands in the body


Q8. What is the role of Hormones in initiating reproductive function in boys?

Ans. The male hormone or testosterone begins to be released by the testes at the onset of puberty. This causes changes in boys


Q9. What is female hormone and it’s role for reproduction?

Ans. In girls, ovaries produce the female hormone or estrogen which makes the breasts development and mammary glands develop inside the breasts.


Q10. What is reproductive phase of  women ?

Ans. The reproductive phase of women is between first menstrual flow  menarche and at 45 to 50 years of age, the menstrual cycle stops which is termed menopause.


Q11. What is  Adam’s apple?

Ans. At puberty boys develop larger voice boxes, The growing voice box in boys can be seen as protruding throat, this is called Adam’s apple. 


Q12. What are Secondary sexual characters?

Ans. Secondary sexual characters are hair grow at various places on the body, breasts develop in girls and facial hair appear in boys, change in voice of boys and secretion of hormones.


Q13. Are there hormones in other animals also? Have they play role to reproduction?

Ans. Yes there are some growth hormones found in animals, metamorphosis in insects is controlled by insect hormones. In a frog, it is controlled by thyroxine, the hormone produced by thyroid.


Q14. If  tadpole do not have enough iodine in water, what  will happen?

Ans. Thyroxine  production requires the presence of iodine in water. If the water in which the tadpoles are growing does not contain sufficient iodine, the tadpoles cannot become adults


Q15. What are sex chromosomes ? 

Ans.. All human beings have 23 pairs of chromosomes in the nuclei of their cells. Two chromosomes out of these are the sex chromosomes, named X and Y.


Q16. Explain Sex determination in the unborn baby.

Ans. When a sperm containing X chromosome fertilises the egg, the zygote would have two X chromosomes and develop into a female child while Y chromosome fertilises the ovum the zygote would develop into a male child


Q17. What is the function of Thyroid gland?

Ans. Thyroid gland  produce the hormone thyroxine, people get goitre caused by lack of thyroxine.


Q18. Is packed food a balanced diet?

Ans. No, Chips and packed or tinned snacks, though very tasty should never replace regular meals as they do not have adequate nutritional value.


Q19. What causes AIDS, what are the causes of its transmission?

Ans. AIDS is caused by a virus, HIV, This virus can pass on to a normal person from an infected person by sharing the used syringes and to infant from the infected mother. The virus can also be transmitted through sexual contact with a person infected with HIV.


Q20. What are the essential part of Reproductive Health?

Ans. During adolescence, balanced diet, personal hygiene and undertake adequate physical exercise become even more essential for good mental and physical health.




Try these :- 


Define personal hygiene and explain its importance in an adolescent’s life.

 Give a brief description of menstruation and menstrual cycle in females.

Name the specific term used for characteristics that help to distinguish males from females and give examples of those as well.

 Name the gland which regulates secretion of hormones from male and female gonads also mention functions of male and female sex hormones.