8 class Chapter: Reaching the Age of Adolescence NOTES

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 8 Class Chapter: Reaching the Age of Adolescence  NOTES

1. What is the term used for chemical secretions of endocrine glands responsible for changes taking place in the body?

Answer: Hormones

2. Define adolescence.

Adolescence is the period between childhood and adulthood.
It usually begins around 11 years and continues up to 18–19 years.

3. What is menstruation? Explain.

Menstruation is the monthly shedding of the uterine lining in females.
If the egg is not fertilised, the inner lining of the uterus breaks down and comes out as blood through the vagina.
This cycle occurs about every month for 2–8 days.

4. List changes in the body that take place at puberty.

  • Rapid increase in height and weight

  • Hair growth in underarms and private parts

  • Reproductive organs mature

  • Boys develop broad shoulders and deeper voice

  • Girls develop breasts and wider hips

  • Acne (pimples) may appear on skin

5. Prepare a Table having two columns depicting the names of endocrine glands and hormones secreted by them.

Endocrine Glands    Hormones
Testis        Testosterone
Ovary        Oestrogen
Pituitary        Growth hormone
Adrenal                Adrenalin
Thyroid        Thyroxine
Pancreas        Insulin

6. What are sex hormones? Why are they named so? State their function.

Sex hormones are hormones produced by the sex organs.

Examples:

  • Oestrogen (female) – develops female characteristics like breast development.

  • Testosterone (male) – develops male characteristics like beard and deep voice.

They are called sex hormones because they control sexual development and reproduction.

7. Choose the correct option.

(a) Adolescents should be careful about what they eat, because
Answer: (ii) proper diet is needed for the rapid growth taking place in their body.

(b) Reproductive age in women starts when their
Answer: (i) menstruation starts.

(c) The right meal for adolescents consists of
Answer: (ii) chapati, dal, vegetables.

8. Write notes on—

(a) Adam’s apple

Adam’s apple is the protruding part of the throat in boys.
It forms due to the growth of the larynx (voice box) during puberty.

(b) Secondary sexual characters

These are body changes that appear during puberty.

Examples:

  • Boys: beard, deep voice, broad chest

  • Girls: breast development, wider hips

(c) Sex determination in the unborn baby

The sex of a baby depends on sex chromosomes (X and Y).

  • Female: XX

  • Male: XY

The sperm determines the sex of the baby.

9. Word game answers

Across

  1. Adam’s apple

  2. Endocrine

  3. Pituitary

  4. Hormone

  5. Insulin

  6. Estrogen

Down

  1. Testosterone

  2. Thyroid

  3. Adolescence

  4. Target site

  5. Larynx

  6. Puberty