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What changes take place in the body during adolescence?

Class 7 ScienceNCERT chapter: Adolescence: A Stage of Growth and Changeइसे हिंदी में पढ़ें

Exam-ready answer

Adolescence is the stage of life between childhood and adulthood, roughly from 10 to 19 years of age. During it, hormones bring about changes such as a sudden increase in height, hair growth in the armpits and pubic region, change in voice and more active sweat and oil glands. The body becomes capable of reproduction; this is called puberty.

Explanation

The changes of adolescence are controlled by hormones, chemical messengers released into the blood by glands. At puberty, the testes in boys begin to produce the hormone testosterone, and the ovaries in girls begin to produce oestrogen. These hormones signal different parts of the body to grow and change, so the body slowly matures and becomes capable of reproduction.

One of the first visible changes is a growth spurt: the bones of the arms and legs lengthen and a person grows taller quickly. In boys, the voice box (larynx) grows larger and forms a visible Adam's apple, and the voice becomes deeper; facial hair appears and the shoulders broaden. In girls, the breasts develop, the region below the waist widens and menstruation, the monthly cycle, begins.

Some changes are common to both. Hair grows in the armpits and pubic region. Sweat and oil glands become more active, so many teenagers get pimples (acne) and need to bathe and wash their face regularly. Moods and feelings can also change quickly. Every person develops at their own pace, so changes coming a little early or late are normal; questions can be discussed with a parent, teacher or doctor.

Points to remember

  1. Adolescence: the period between childhood and adulthood, roughly 10 to 19 years of age.
  2. Puberty: the set of changes that make the body capable of reproduction.
  3. Hormones control these changes: testosterone from the testes in boys and oestrogen from the ovaries in girls.
  4. Changes in both: growth spurt, hair in armpits and pubic region, active sweat and oil glands, mood changes.
  5. Boys: deeper voice, Adam's apple, facial hair, broader shoulders. Girls: breast development, wider hips, start of menstruation.

Exam tip

Arrange the answer under three headings — changes in boys, changes in girls, changes in both — and name the hormone responsible. Use the exact terms puberty, growth spurt, larynx, testosterone and oestrogen.

Questions students also ask

Why does the voice of boys crack during adolescence?
The voice box, or larynx, grows larger and the vocal cords become longer and thicker. While the muscles adjust to this growth, the voice may sound hoarse or crack. After some time, the voice settles into a deeper adult tone.
Why do teenagers get pimples?
During adolescence, hormones make the oil and sweat glands of the skin more active. Extra oil can block the openings of the skin pores, which leads to pimples or acne. Washing the face regularly helps, and a doctor can advise if acne becomes severe.
What kind of food does the body need during adolescence?
The body grows fast, so it needs a balanced diet: proteins for growth, carbohydrates and fats for energy, and vitamins and minerals. Milk, pulses, green leafy vegetables, fruits and iron-rich foods support healthy bones, muscles and blood.

Chapter labels help you find the topic in your textbook. Check your own edition: chapter names and order can change. These are Know.it explanations, not official NCERT solutions.