NCERT Curiosity · Class 7 · Science
Adolescence: A Stage of Growth and Change
“You've become so tall!” — two cousins noticing each other grow, right in the middle of adolescence.
Physical Changes Emotional Changes Nutrition Staying Healthy
Key idea
Visible Physical Changes
Adolescence brings noticeable changes in height, voice, and hair growth — timing varies normally between individuals.

Height and build

A noticeable increase in height, weight, and body shape.

Voice

The voice box grows, giving a deeper voice — more noticeable in boys.

Hair growth

New hair appears in new places in both sexes.

Key idea
Acne and Secondary Sexual Characteristics

Acne

Increased oily skin secretions can clog pores, causing pimples.

Puberty

Voice change, facial hair, and body development mark the stage where the body becomes capable of reproduction.

Key idea
28–30
Days in a typical menstrual cycle (a normal healthy range is 21–35). Menstruation, the bleeding phase, usually lasts 3–7 days.
Key idea
There is no scientific basis for menstruation taboos.
Some communities isolate menstruating girls due to long-standing myths. Menstruation is a normal, healthy part of the reproductive cycle — a scientific outlook should be encouraged.
Key idea
Emotional and Behavioural Changes
Stronger emotions

Mood swings and heightened sensitivity, compared to childhood.

Channelled well

These same changes can lead to creativity, compassion, and greater social involvement.

Key idea
Nutrition During Adolescence

Protein, carbs, fats

Alongside vitamins and minerals, needed for proper growth.

Calcium

For strong, healthy bones.

Iron

For healthy blood formation.

Key idea
Hygiene, and Government Support

Menstrual Hygiene Scheme

Free or low-cost pads for rural adolescent girls.

RKSK

Overall adolescent health, through peer education.

Suvidha Initiative

Biodegradable pads via Jan Aushadhi Kendras.

Key idea
Staying Healthy

Physical activity

Regular activity keeps the body and mind fit, and boosts mood.

Cyberbullying

Report harassment or false rumours to parents or teachers — don't hide it.

Avoiding substances

Tobacco, alcohol, or drugs cause real harm. The National De-addiction Helpline: 14446.

Key idea
Hormones are the “why” behind adolescence.
Nearly every change in this chapter — physical, reproductive, and emotional — traces back to hormones: chemicals produced in the body that regulate growth, mood, and behaviour.
Chapter · key terms to remember
Key Terms

Adolescence

The stage between childhood and adulthood, ~10–19 years.

Puberty

When the body becomes capable of reproduction.

Secondary sexual characteristics

Features like voice change, facial hair, breast development.

Chapter · key terms to remember
More Key Terms

Acne

Pimples from increased oily skin secretions.

Menstruation

The bleeding phase of the menstrual cycle.

Menstrual cycle

The recurring reproductive cycle, ~28–30 days.

Chapter · key terms to remember
More Key Terms

Hormones

Body chemicals regulating growth, mood, and behaviour.

Substance abuse

Repeated, addictive use of harmful substances.

Opening

Jump to a section — tap anywhere else to close