NCERT Class 8 Science Science: Chapter 7 — Reaching the Age of Adolescence
This chapter, "Reaching the Age of Adolescence," from NCERT Class 8 Science, explores the transformative period of human development. It defines adolescence as the phase between childhood and adulthood, typically from age 11 to 18-19, leading to reproductive maturity. This stage, also known as puberty, is marked by significant physical changes. The chapter details the most noticeable change: a sudden spurt in height due to elongating long bones. It also introduces the concept of hormones playing a crucial role in these changes. Understanding adolescence is vital for students to comprehend their own growth and development, aligning with the CBSE curriculum's focus on human biology.
Quick info
| Board | CBSE / NCERT |
|---|---|
| Class | Class 8 |
| Subject | Science |
| Book | Science |
| Chapter | Chapter 7 — Reaching the Age of Adolescence |
| Language | English |
| PDF type | NCERT Textbook |
| Session | CBSE 2026 |
| Reading time | 3 minutes |
| Word count | 560 |
Learning outcomes
- Define adolescence and puberty.
- Identify the typical age range for adolescence.
- Describe the most noticeable physical change during puberty: increased height.
- Understand that hormones play a role in the changes during adolescence.
Vocabulary
| Word | Meaning |
|---|---|
| Adolescence | The period of life when the body undergoes changes, leading to reproductive maturity. |
| Puberty | The stage of sexual maturation in humans, marked by physical changes and the onset of reproductive capability. |
| Adult | A fully grown person who is legally recognized as an adult. |
| Reproduction | The biological process by which new individual organisms – 'offspring' – are produced from their 'parents'. |
| Hormones | Chemical messengers produced in the body that regulate various functions, including growth and development. |
| Teenagers | Adolescents, typically between the ages of 13 and 19. |
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Practice questions
- What is the age range for adolescence? Answer: Adolescence typically begins around the age of 11 and lasts up to 18 or 19 years of age.
- What is another name for adolescents? Answer: Adolescents are also called 'teenagers'.
- What is the most conspicuous change during puberty? Answer: The most conspicuous change during puberty is the sudden increase in height.
- When does puberty end? Answer: Puberty ends when an adolescent reaches reproductive maturity.
Frequently asked questions
What is adolescence?
Adolescence is the period of life when the body undergoes changes, leading to reproductive maturity. It typically spans from age 11 to 18 or 19.
What is puberty?
Puberty is the stage of sexual maturation in humans, marked by physical changes that make a child grow into an adult capable of reproduction.
When does adolescence begin and end?
Adolescence usually begins around age 11 and lasts until about age 18 or 19. It may start a year or two earlier in girls than in boys.
What is the most noticeable physical change during puberty?
The most noticeable change during puberty is a sudden increase in height, as the long bones of the arms and legs elongate.
Why are adolescents also called teenagers?
Adolescents are also called teenagers because this period covers the 'teens' (13 to 18 or 19 years of age).
What role do hormones play in adolescence?
Hormones play a crucial role in bringing about the changes that occur in the human body during adolescence, leading to reproductive maturity.
Related resources
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Topics covered
NCERT Class 8 Science — Science — Chapter 7 — Reaching the Age of Adolescence. Verified by NCERT Help Editorial Team. Reviewed on 29 Jul 2026. Last updated 10 Aug 2026.