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Schooling · Class 7 · Science · Adolescence: A Stage of Growth and Change · Chapter on a page

CBSE Class 7 · Science · NCERT Curiosity

Adolescence: A Stage of Growth and Change: chapter on a page

A cut of Shishya's notes for this chapter: the first paragraph of the introduction and the key ideas, formulas and facts, common mistakes and quick revision lists, word for word. Nothing is added or reworded; the worked examples are left out (they are on the chapter page).

About the notes: Written by Shishya's AI on 26 Sept 2026 from the chapter's title and class level, in Shishya's own words — not a copy or summary of the textbook. Read the official chapter for the book's own text, activities and exercises.

This note's current text has no applied fact-check on record.

Mind map

Drawn from the same notes by a fixed rule (no AI): each label is the item's own words — its bold term, its label before a colon, a short formula as written, or its first words.

Mind map of Adolescence: A Stage of Growth and Change: Key ideas, Formulas and facts, Watch out forKey ideasAdolescence is the period between…Puberty is the time when the body…Hormones are chemical messengers…In boys, the hormone testosterone…Both boys and girls grow taller…Girls begin the menstrual cycle, a…Emotional changes are also common.…Formulas and factsAdolescencePubertyHormonesPituitary glandMenstruationAdam's appleSecondary sexual characteristicsWatch out forThinking puberty happens at the same…Believing mood swings mean something…Confusing adolescence with pubertyThinking menstruation is a diseaseIgnoring personal hygiene during…Adolescence: A Stageof Growth and Change
The mind map as a list
  • Key ideas
    • Adolescence is the period between…
    • Puberty is the time when the body…
    • Hormones are chemical messengers…
    • In boys, the hormone testosterone…
    • Both boys and girls grow taller…
    • Girls begin the menstrual cycle, a…
    • Emotional changes are also common.…
  • Formulas and facts
    • Adolescence
    • Puberty
    • Hormones
    • Pituitary gland
    • Menstruation
    • Adam's apple
    • Secondary sexual characteristics
  • Watch out for
    • Thinking puberty happens at the same…
    • Believing mood swings mean something…
    • Confusing adolescence with puberty
    • Thinking menstruation is a disease
    • Ignoring personal hygiene during…

What this chapter is about

This chapter helps you understand the special phase of life called adolescence. Adolescence is the time when a child's body changes and grows into an adult body. It usually begins around age 10–12 and lasts until about 18–19 years. You are probably in this stage right now or will enter it soon.

Key ideas

  • Adolescence is the period between childhood and adulthood, roughly from age 11 to 19 years. A person in this stage is called an adolescent or teenager.
  • Puberty is the time when the body begins to develop adult features. It starts earlier in girls (around 10–12 years) than in boys (around 11–13 years).
  • Hormones are chemical messengers made by glands. They control the changes during puberty. The pituitary gland in the brain tells other glands when to release hormones.
  • In boys, the hormone testosterone causes growth of facial hair, deeper voice and broader shoulders. In girls, the hormone oestrogen causes breast development and widening of hips.
  • Both boys and girls grow taller quickly during adolescence. This is called a growth spurt.
  • Girls begin the menstrual cycle, a monthly process where the uterus prepares for pregnancy. If pregnancy does not occur, the uterus lining sheds as blood. This is called menstruation or periods.
  • Emotional changes are also common. You may feel happy one moment and upset the next. This is normal and linked to hormonal changes.
  • Good nutrition, regular exercise, enough sleep and personal hygiene are very important during adolescence.

Formulas and facts to remember

  • Adolescence – the period of life from about 11 to 19 years when the body changes from child to adult.
  • Puberty – the stage when reproductive organs mature and secondary sexual features appear.
  • Hormones – chemicals released by glands that control body functions; examples are testosterone and oestrogen.
  • Pituitary gland – a small gland at the base of the brain that controls other glands; often called the master gland.
  • Menstruation – the monthly shedding of the uterus lining in girls; the cycle is usually about 28 days.
  • Adam's apple – the voice box (larynx) grows larger in boys, making their voice deeper and showing a bulge in the throat.
  • Secondary sexual characteristics – features like facial hair in boys and breast development in girls that appear at puberty but are not directly part of reproduction.

Common mistakes

  • Thinking puberty happens at the same age for everyone → Puberty timing varies; girls often start 1–2 years earlier than boys.
  • Believing mood swings mean something is wrong → Emotional ups and downs are normal during adolescence due to hormones.
  • Confusing adolescence with puberty → Adolescence is the whole period (11–19 years); puberty is just the start when physical changes begin.
  • Thinking menstruation is a disease → Menstruation is a natural, healthy process in girls, not an illness.
  • Ignoring personal hygiene during this stage → Sweat glands become more active; regular bathing and clean clothes prevent body odour and infections.

Quick revision

  • Adolescence = transition from child to adult, roughly ages 11–19.
  • Puberty = body starts showing adult features; controlled by hormones.
  • Testosterone in boys, oestrogen in girls drive physical changes.
  • Menstrual cycle in girls is about 28 days; menstruation is normal.
  • Balanced diet, exercise, sleep and hygiene are essential during adolescence.
  • Mood changes are natural; talk to a trusted adult if worried.