Adolescence: A Stage of Growth and Change – Class 7 Science Chapter 6 Notes & NCERT PDF

Introduction

A seed germinates, grows into a sapling and a young plant, and only after reaching maturity can it make flowers, fruits and seeds. Animals, too, must grow and mature before they can reproduce. Human life has stages — infancy, childhood, adolescence, adulthood and old age — and each person passes through them at their own pace.

Until about 10–12 years, most changes are in height and weight. After this, new changes begin, marking the start of adolescence, a period of rapid growth and development, typically between the ages of 10 and 19. The chapter explains these changes and how to handle this stage with a sense of responsibility.

Key Concepts

6.1 Growing with age: the teenage years

During the summer vacation, Venkatesh visits his grandparents. His 12-year-old cousin Devyani notices he has a thin moustache and his voice has changed; he notices she has become tall. In Activity 6.1, students write changes they notice from Grades 5 to 8 on paper slips (no names), put them in a jar, and discuss them.

Adolescence: the stage of development between childhood and adulthood, starting around 10 years and continuing up to about 19 years.

Common changes described in the book:

Key point: the timing, nature and extent of these changes vary among individuals, and these variations are completely normal.

Changes like voice change, facial and chest hair in boys, and breast development in girls help distinguish males from females but are not directly involved in reproduction. These are secondary sexual characteristics. They mark the onset of puberty.

Puberty: the stage in which the body of an adolescent undergoes external and internal changes to develop into an adult capable of reproduction.

6.2 Changes that indicate reproductive capability

Internal changes include the maturation of body parts involved in reproduction. In girls, an important change is the start of the menstrual cycle, commonly called "the period". It usually recurs every 28–30 days, though cycles of 21–35 days are common in healthy girls. The phase when blood is discharged is menstruation, lasting three to seven days; some girls feel pain or discomfort in the lower abdomen. Menstruation usually stops naturally by 45–55 years of age.

Breaking myths: wrong beliefs about menstruation cause fear, shame and guilt. Isolating menstruating girls has no scientific basis. A scientific outlook helps society support women's reproductive health.

6.3 Emotional and behavioural changes

Adolescence brings stronger emotions than childhood — mood swings, increased sensitivity, excitement or confusion. The book suggests positive outlets: music, dance, sports, self-exploration that leads to creativity, compassion and social work. Understanding how emotions affect behaviour helps us make better choices.

6.4 Making adolescence a joyful experience

6.5 Why do these changes happen?

Many changes, including menstruation and other signs of puberty, are mainly due to hormones — chemicals produced in our bodies and released at the right time in response to signals from the brain. Some hormones also influence mood and behaviour.

Activities in the Chapter

Key Terms

Real-life Connections

Common Misconceptions

Keep the Curiosity Alive (exercise hints)