"Venkatesh, you have a thin moustache now!" "Your voice has changed!" "You've become so tall, Devyani!" — the sound of two cousins noticing each other grow up.
Key idea
The Stages of Life
Adolescence (10–19 yrs)
Key idea
Visible Physical Changes
1
Height and build
A noticeable increase in height. Boys often develop broader shoulders and chest; girls develop breasts and other body changes.
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2
Weight
A gradual increase in body weight is a normal part of this stage of growth.
Key idea
Voice Changes and Hair Growth
1
Voice
The voice box (larynx) grows, giving boys a hoarser voice — sometimes visible as the Adam's apple. Girls' voice boxes grow too, though less noticeably.
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2
Hair growth
New hair growth appears in the armpits and pubic region in both sexes. Boys often develop facial hair — timing and extent vary normally between individuals.
Key idea
Acne and Secondary Sexual Characteristics
AcneIncreased oily skin secretions during adolescence can clog pores, causing reddish pimples.
Secondary sexual characteristicsFeatures like voice change, facial hair, and breast development mark the onset of puberty — the stage where the body becomes capable of reproduction.
Key idea
The Menstrual Cycle
1
The cycle
Typically recurs every 28–30 days, with a normal healthy range of 21–35 days.
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2
Menstruation
The bleeding phase, usually lasting 3–7 days. It begins at puberty and stops naturally around ages 45–55.
Key idea
There Is No Scientific Basis for Taboos
Some communities isolate menstruating girls due to long-standing myths and taboos.
What science tells usThese practices have no scientific basis. Menstruation is a normal, healthy part of the reproductive cycle, and a scientific outlook should be encouraged.
Key idea
Emotional and Behavioural Changes
1
Stronger emotions
Adolescence often brings mood swings and heightened sensitivity, compared to childhood.
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2
Channelled well
These same emotional changes can lead to creativity, compassion, and greater social involvement.
Key idea
Nutrition During Adolescence
Adolescents need proteins, carbohydrates, fats, vitamins, and minerals for proper growth.
CalciumFor strong, healthy bones.
IronFor healthy blood formation.
Key idea
Hygiene, and Support from the Government
Menstrual hygiene is maintained with sanitary pads or reusable cloth pads; used pads should be wrapped and disposed of in a dustbin.
Scheme | What it does
Menstrual Hygiene Scheme (MHS)
Free or low-cost pads for rural adolescent girls
Rashtriya Kishor Swasthya Karyakram (RKSK)
Overall adolescent health, through peer education
Suvidha Sanitary Napkin Initiative
Biodegradable pads via Jan Aushadhi Kendras
Key idea
Physical Activity and a Balanced Social Life
1
Physical activity
Regular activity keeps the body and mind fit, and helps boost mood.
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2
Cyberbullying
Harassment through digital platforms — misleading messages, false rumours, or sharing private information without consent. Report it to parents or teachers, don't hide it.
Key idea
Avoiding Harmful Substances
1
Substance abuse
Repeated, addictive use of tobacco, alcohol, or drugs can cause breathing difficulties, memory loss, and lung damage.
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2
Getting help
The Nasha Mukt Bharat Abhiyaan spreads awareness against substance abuse. The National De-addiction Helpline (14446) offers confidential support.
Key idea
Hormones: The 'Why' Behind Adolescence
Nearly every change in this chapterphysical, reproductive, and emotional — traces back to one cause.
HormonesChemicals produced in the body, released in response to brain signals, that regulate growth, development, 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.
Questions for your notebook
Write these down, then discuss
1
Ramesh, 11, developed pimples and his mother said it's from ongoing biological changes. (i) What could cause this? (ii) What can he do for relief?
2
Which food group is a better choice for adolescents, and why?
3
Unscramble the underlined word in each sentence: (i) nstmnoiaretu — blood discharge every 28–30 days. (ii) iceov xob — enlarged, causing hoarser voice. (iii) urtypeb — the body preparing for adulthood. (iv) lahoclo and srugd — say NO, as they're addictive.
Project as-is — students copy the questions, then the class discusses answers together.