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Adolescence: A Stage of Growth and Change

NCERT Class 7 · Science Based on NCERT Class 7 Science textbook · Free CBSE study kit

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Chapter Notes

Overview
This chapter explains the period of adolescence, typically between ages 10 and 19, when a child's body undergoes physical, emotional, and behavioural changes to prepare for adulthood. It covers observable changes like height increase, voice change, and pimples, as well as internal changes like the menstrual cycle in girls. The chapter also emphasizes the importance of nutrition, hygiene, physical activity, avoiding harmful substances, and understanding the role of hormones. The one big idea is that adolescence is a natural, normal stage of growth that requires responsible care and positive habits.
Key Concepts (12)
Adolescence
The period of life between childhood and adulthood, typically from about 10 to 19 years of age, marked by rapid growth and development.
e.g. A 13-year-old boy noticing his voice becoming deeper and his height increasing is experiencing adolescence.
Puberty
The stage in which the body of an adolescent undergoes external and internal changes to develop into an adult capable of reproduction.
e.g. When a girl starts her menstrual cycle at age 12, she has entered puberty.
Secondary sexual characteristics
Characteristic changes that help distinguish males from females but are not directly involved in the process of reproduction.
e.g. Growth of facial hair in boys and development of breasts in girls are secondary sexual characteristics.
Menstrual cycle
A recurring cycle in adolescent girls, generally every 28–30 days, involving the discharge of blood from the body, known as menstruation.
e.g. A 14-year-old girl gets her period every 28 days, which is part of her menstrual cycle.
Menstruation
The phase of the menstrual cycle when blood discharge occurs from the body, lasting three to seven days.
e.g. During menstruation, a girl uses a sanitary pad to maintain hygiene.
Hormones
Certain chemicals produced in the body that regulate various aspects of growth and development, including changes during adolescence.
e.g. Hormones cause the voice box to grow in boys during adolescence.
Adam's apple
A bump in the throat region caused by the growth of the voice box in adolescent boys, though not noticeable in every individual.
e.g. A 15-year-old boy notices a small lump on his throat; this is his Adam's apple.
Acne
A skin condition during adolescence where small, reddish pimples appear on the face due to increased oily secretions clogging skin pores.
e.g. A 13-year-old girl gets pimples on her forehead because of acne.
Substance abuse
The regular use of harmful substances like tobacco, alcohol, or drugs, which are addictive and damage physical and mental health.
e.g. A person who starts smoking cigarettes regularly and cannot stop is suffering from substance abuse.
Addictive substances
Substances such as tobacco, gutka, cigarettes, beedi, alcohol, or illegal drugs that create a strong urge to consume them repeatedly.
e.g. Gutka is an addictive substance that many people find hard to quit.
Cyberbullying
The use of digital devices such as phones or computers to harass others by sending misleading messages, spreading false rumours, or sharing personal information without consent.
e.g. A classmate spreading a false rumour about you on WhatsApp is an example of cyberbullying.
Nasha Mukt Bharat Abhiyaan
A government initiative launched by the Ministry of Social Justice and Empowerment to spread awareness about avoiding substance abuse, with special focus on prevention among early-age children.
e.g. Schools conduct rallies under the Nasha Mukt Bharat Abhiyaan to teach students to say no to drugs.
How It Works
Onset of Adolescence
  1. Around age 10–12, the body begins to show changes beyond height and weight.
  2. These changes mark the onset of adolescence, a period of rapid growth and development.
  3. The body prepares for adulthood, and reproductive capability develops.
  4. Adolescence typically lasts until age 19.
💡 Adolescence starts around 10 years, not at birth or at a fixed age for everyone.
Development of Secondary Sexual Characteristics
  1. In boys, the voice box grows, causing a hoarse voice and sometimes an Adam's apple.
  2. Boys develop facial hair (moustache, beard), chest hair, and broader shoulders.
  3. In girls, breasts develop, and the voice box grows slightly but not as much as in boys.
  4. Both boys and girls grow hair in armpits and pubic region.
  5. Facial skin may develop acne due to increased oily secretions.
💡 These changes are not directly involved in reproduction but distinguish males from females.
The Menstrual Cycle
  1. In adolescent girls, the menstrual cycle begins, generally recurring every 28–30 days (range 21–35 days).
  2. The phase of blood discharge is called menstruation, lasting 3–7 days.
  3. Some girls may feel pain or discomfort in the lower abdomen during this time.
  4. Menstruation stops naturally around age 45–55, marking the end of reproductive capability.
💡 Menstruation is a natural sign of good reproductive health, not a disease or impurity.
Role of Hormones in Adolescence
  1. The brain sends signals to different parts of the body.
  2. In response, certain chemicals called hormones are produced and released.
  3. These hormones regulate growth, development, and changes like menstruation and voice change.
  4. Some hormones also influence mood and behaviour.
💡 Hormones are the 'why' behind all adolescent changes — they are natural and necessary.
Substance Abuse and Addiction
  1. A person may be tempted or pressured by peers to try harmful substances like tobacco, alcohol, or drugs.
  2. Once consumed, these substances create a strong urge to take them again (addiction).
  3. Over time, regular use leads to substance abuse, causing serious health problems like lung damage and memory loss.
  4. The first step to overcoming addiction is seeking help from family, friends, or counsellors.
💡 Addiction can start with 'just one time' — it is safest to say NO the first time.
Exam Traps — Don't Make These Mistakes
⚠ Confusing Adolescence with Puberty
✗ Adolescence and puberty are the same thing.
→ Adolescence is the broader period of growth from childhood to adulthood (ages 10–19), while puberty is the specific stage within adolescence when the body becomes capable of reproduction.
✓ Adolescence is the period of change from childhood to adulthood; puberty is the stage when the body develops reproductive capability.
⚠ Saying Menstruation Stops at Age 45
✗ Menstruation stops at exactly age 45.
→ The textbook says menstruation stops 'usually by the age of 45–55', not exactly 45. It is a range.
✓ Menstruation generally ends between the ages of 45 and 55.
⚠ Calling Pimples and Acne the Same Thing
✗ Pimples and acne are the same condition.
→ Acne is the skin condition, and pimples are a manifestation (symptom) of it. They are not identical.
✓ Acne is a skin condition that causes pimples; pimples are the visible bumps that appear due to acne.
⚠ Thinking Only Boys Get Voice Changes
✗ Only boys experience voice changes during adolescence.
→ The voice box also grows in adolescent girls, but it is not as big as in boys, leading to only slight changes in voice.
✓ Both boys and girls experience voice changes, but the change is more noticeable in boys due to a larger voice box.
⚠ Believing All Changes Happen at the Same Age for Everyone
✗ All adolescents experience changes at the same age.
→ The textbook clearly states that timing, nature, and extent of changes vary among individuals, and each person experiences adolescence at their own pace.
✓ Changes during adolescence vary from person to person in timing and extent; this is completely normal.
Compare & Contrast
Definition and scope
Adolescence
Puberty
Adolescence is the entire period of growth from childhood to adulthood (ages 10–19), while puberty is the specific stage within adolescence when the body becomes capable of reproduction.
Involvement in reproduction
Secondary sexual characteristics
Primary reproductive changes
Secondary sexual characteristics (like voice change, facial hair, breast development) help distinguish males from females but are not directly involved in reproduction, whereas primary changes (like the menstrual cycle) are directly involved in reproductive capability.
Exam Focus
Marks pattern: 2 MCQs (1 mark each), 1 Very Short Answer (1 mark), 1 Short Answer (3 marks), 1 Long Answer (5 marks)
Most asked: Definition and age range of adolescence · Secondary sexual characteristics in boys and girls · Menstrual cycle and menstruation · Role of hormones · Harmful effects of addictive substances
Don't skip: Differentiate between adolescence and puberty (3 marks); Explain the menstrual cycle and its importance (5 marks); List and describe secondary sexual characteristics in boys and girls (5 marks)
One-Line Revision (read aloud before the exam)
  1. Adolescence is the period of growth from childhood to adulthood, typically between ages 10 and 19.
  2. Puberty is the stage when the body becomes capable of reproduction.
  3. Secondary sexual characteristics distinguish males from females but are not directly involved in reproduction.
  4. The menstrual cycle generally occurs every 28–30 days and menstruation lasts 3–7 days.
  5. Menstruation is a natural process and a sign of good reproductive health.
  6. Hormones are chemicals produced in the body that control changes during adolescence.
  7. Acne is a skin condition that causes pimples due to increased oily secretions.
  8. The Adam's apple is a bump in the throat caused by the growth of the voice box in boys.
  9. Addictive substances like tobacco, alcohol, and drugs cause serious health problems and should be avoided.
  10. Substance abuse means regular use of harmful, addictive substances.
  11. Cyberbullying is using digital devices to harass or spread false rumours about others.
  12. A balanced diet with proteins, carbohydrates, fats, vitamins, and minerals is essential during adolescence.
  13. Personal hygiene, especially during menstruation, prevents infections.
  14. Regular physical activity keeps the body and mind fit during adolescence.
  15. Saying 'NO' to harmful substances the first time prevents addiction.
  16. The Nasha Mukt Bharat Abhiyaan aims to prevent substance abuse among youth.
  17. Emotional changes like mood swings are normal during adolescence and can be managed through positive activities.

MCQs — 10 Questions with Answers

Q1. At what age does adolescence typically begin?

  • A. Around 10-12 years ✓
  • B. Around 5-7 years
  • C. Around 15-17 years
  • D. Around 20-22 years

Answer: A — Adolescence typically occurs between ages 10-19, with noticeable changes beginning around 10-12 years after earlier growth stages.

Q2. What is the bump in the throat of adolescent boys called?

  • A. Thyroid gland
  • B. Adam's apple ✓
  • C. Windpipe
  • D. Larynx bump

Answer: B — The Adam's apple is the visible bump in the throat caused by growth of the voice box during male puberty.

Q3. Which of the following is NOT a secondary sexual characteristic?

  • A. Facial hair in boys
  • B. Breast development in girls
  • C. Increase in height ✓
  • D. Voice changes in boys

Answer: C — Increase in height is a general physical change affecting both boys and girls, not a secondary sexual characteristic that distinguishes males from females.

Q4. What is the typical duration of a normal menstrual cycle?

  • A. 14-21 days
  • B. 21-35 days or 28-30 days average ✓
  • C. 35-42 days
  • D. 7-14 days

Answer: B — A typical menstrual cycle averages 28-30 days but can range from 21-35 days in healthy girls, which is completely normal.

Q5. A girl in your class notices several pimples on her face. What is the scientific reason for this during adolescence?

  • A. Poor hygiene and dirt accumulation
  • B. Eating too much chocolate and oily food
  • C. Increased oily secretions from skin clogging pores and causing infections ✓
  • D. Drinking insufficient water

Answer: C — Acne and pimples during adolescence are caused by increased oil production from the skin that clogs pores, not dietary factors or hygiene alone.

Q6. Your friend is worried because his voice is becoming hoarse during adolescence. What should you tell him?

  • A. This is abnormal and he should see a doctor immediately
  • B. This is a normal secondary sexual characteristic caused by voice box growth during puberty ✓
  • C. This means he is catching a throat infection
  • D. This will continue to get worse throughout his life

Answer: B — Voice changes in adolescent boys are a normal secondary sexual characteristic caused by the growth of the voice box during puberty.

Q7. Why is a nutritious diet particularly important for adolescent girls like Devyani in the story?

  • A. To prevent mood swings completely
  • B. To support rapid growth, development, and compensate for iron loss during menstruation ✓
  • C. To make them taller than boys
  • D. To prevent all emotional changes

Answer: B — Adolescent girls need proper nutrition for rapid growth and development, and especially need iron-rich foods because menstruation causes blood loss monthly.

Q8. How do variations in the timing and extent of physical changes during adolescence affect students?

  • A. Some students mature faster while others mature slower, which is completely normal ✓
  • B. All students must develop facial hair and breasts at the same age
  • C. Students who develop faster are healthier than those who develop slower
  • D. Variations indicate that some students are abnormal

Answer: A — Each person experiences adolescence at their own pace; variations in timing, nature, and extent of changes among individuals are completely normal and healthy.

Q9. A girl in Class 7 feels embarrassed about starting her menstrual cycle. Based on the chapter, which statement is most helpful?

  • A. Menstruation is a natural biological process that shows reproductive maturity, and myths about it have no scientific basis ✓
  • B. She should avoid all physical activities and social events during menstruation
  • C. Menstruation indicates there is something wrong with her body
  • D. She should isolate herself from family and friends

Answer: A — The chapter emphasizes that menstruation is a natural, healthy process; myths and taboos have no scientific basis, and a scientific outlook promotes good reproductive health.

Q10. How do emotional changes during adolescence potentially affect a student's behaviour and choices?

  • A. Emotional changes make all adolescents behave badly
  • B. Stronger emotions may lead to positive changes like joining social work or developing new interests, or negative behaviours if not managed thoughtfully ✓
  • C. Emotional changes have no effect on behaviour
  • D. Only girls experience emotional changes during adolescence

Answer: B — The chapter explains that stronger emotions during adolescence can influence behaviour both positively (social involvement, creativity) and negatively, depending on how adolescents process and respond to these emotions.

Flashcards

What is adolescence and at what age does it typically begin?

Adolescence is the stage of life between childhood and adulthood lasting from age 10-19 years, marked by rapid growth and development.

Define secondary sexual characteristics with one example.

Secondary sexual characteristics are observable body changes that mark puberty and help distinguish males from females, such as facial hair in boys or breast development in girls.

What is the Adam's apple and why does it appear in adolescent boys?

The Adam's apple is a bump in the throat formed by the growth of the voice box, which enlarges during puberty causing boys' voices to become deeper.

What is acne and what causes it during adolescence?

Acne is a skin condition where small reddish pimples appear, caused by increased oily secretions from the skin during adolescence that clog pores and lead to infections.

How long is a typical menstrual cycle and what phase involves blood discharge?

A typical menstrual cycle lasts 28-30 days (ranging from 21-35 days), and the menstruation phase with blood discharge lasts 3-7 days.

Name one emotional change that occurs during adolescence.

Mood swings are a common emotional change where adolescents experience rapid shifts in feelings and emotions during this stage.

Why is proper nutrition especially important during adolescence?

Adolescence is a period of rapid growth and development, so adequate proteins, carbohydrates, fats, vitamins, and minerals are essential for proper physical growth and energy.

What are the differences in voice changes between adolescent boys and girls?

The voice box grows more in boys than girls; boys experience a hoarse or deeper voice change while girls experience only slight changes in voice.

At what age does menstruation typically stop in women?

Menstruation stops naturally between ages 45-55, marking the end of reproductive capability in a woman's life.

Why is it important to break myths about menstruation?

Breaking myths about menstruation promotes scientific understanding, reduces unnecessary fear and shame, and supports good reproductive health in women.

Important Board Questions

What is puberty? [1 mark]

Define as the stage when body develops reproductive capability and external/internal changes occur; lasts roughly from age 10-19.

Explain why the appearance of facial hair in boys and breast development in girls are called secondary sexual characteristics. [2 marks]

These changes mark puberty and distinguish males from females, but aren't directly involved in reproduction; they show body is preparing for adulthood.

List three physical changes that occur during adolescence and explain how each helps the body prepare for adulthood. Give one Indian food example that supports these changes. [3 marks]

Select from: height increase, weight gain, voice changes, hair growth, skin changes. Explain how each indicates maturity. Example: Milk and paneer provide calcium and protein for bone and muscle growth.

Describe the menstrual cycle in adolescent girls, explain why breaking myths about menstruation is important, and suggest two ways to support emotional well-being during adolescence. Draw and label a simple diagram showing the approximate 28-30 day menstrual cycle. [5 marks]

Define menstrual cycle (28-30 days average, bleeding phase 3-7 days); explain myths have no scientific basis and hinder women's health; suggest activities like sports, creative pursuits, or social work. Diagram should show cycle phases starting from Day 1 of menstruation to Day 28-30 with menstruation phase marked.

Assertion-Reason Questions for Adolescence: A Stage of Growth and Change

Q1. Assertion (A):

Adolescence is a period of rapid growth and development typically occurring between ages 10-19.

Reason (R):

During adolescence, the body prepares for adulthood through various physical, emotional, and behavioral changes.

Answer: A — Both A and R are true, and R is the correct explanation of A — Both the assertion and reason are true according to the textbook. The reason correctly explains why adolescence occurs during this period—it is the stage when the body undergoes changes to prepare for adulthood. This is directly stated in the chapter.

Q2. Assertion (A):

Secondary sexual characteristics such as facial hair in boys and breast development in girls are directly involved in the reproductive process.

Reason (R):

Secondary sexual characteristics mark the onset of puberty and help distinguish males from females.

Answer: D — A is false but R is true — The assertion is false. The textbook explicitly states that secondary sexual characteristics are 'not directly involved in the process of reproduction.' However, the reason is true—they do mark the onset of puberty and help distinguish males from females. This is a case where the reason is true but doesn't explain a false assertion.

Q3. Assertion (A):

The menstrual cycle in adolescent girls typically recurs every 28-30 days and is a sign of good reproductive health.

Reason (R):

Menstruation is the phase when blood discharge occurs and is part of the natural reproductive process that prepares the body for pregnancy.

Answer: B — Both A and R are true, but R is NOT the correct explanation of A — Both the assertion and reason are true. The cycle does recur every 28-30 days and is a sign of good reproductive health as stated in the text. The reason about menstruation being part of the reproductive process is also true, but it doesn't directly explain why the cycle recurs at this specific interval. The reason is not the correct explanation for the assertion, even though both are true.

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Case-Based Questions (CBQ) for Adolescence: A Stage of Growth and Change

Case Study:

Ravi is a 12-year-old boy who recently noticed significant changes in his body. He has grown about 4 inches taller in the last year, his shoulders have become broader, and his voice has become deeper and sometimes sounds hoarse. He also noticed fine hair appearing on his upper lip and chin. At school, some of his classmates haven't shown these changes yet, which made Ravi worried that something was wrong with him. His mother assured him that these changes are normal and that every boy goes through them at different times.

Q1. Which of the following changes observed in Ravi are secondary sexual characteristics?

  • A. Only the increase in height
  • B. The broader shoulders, deeper voice, and facial hair ✓
  • C. Only the voice changes
  • D. All the mentioned changes including height increase

Answer: B

Q2. Why is Ravi experiencing these changes at a different time than his classmates?

  • A. He has a developmental disorder
  • B. He is eating different food than his classmates
  • C. Variations in timing of adolescent changes among individuals is completely normal ✓
  • D. His classmates are not going through adolescence

Answer: C

Q3. What stage of development is Ravi currently experiencing?

  • A. Childhood
  • B. Adolescence ✓
  • C. Adulthood
  • D. Infancy

Answer: B

Q4. Which internal change is most likely also occurring in Ravi at this stage, even though it is not visible?

  • A. The development of secondary sexual characteristics
  • B. A decrease in height growth rate
  • C. Maturation of reproductive organs ✓
  • D. A decrease in muscle strength

Answer: C

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