Adolescence: A Stage of Growth and Change - Class 7 Science Notes

Adolescence: A Stage of Growth and Change 🌱👦👧

Adolescence is a critical stage in life, marked by growth and change between childhood and adulthood. This detailed note covers the important aspects of adolescence as covered in Class 7 Science, supported with explanations for easy understanding.

Introduction to Growth and Change in Living Beings

The journey of growth in plants starts with a seed. When properly nourished, this seed grows into a sapling and eventually a mature plant with flowers and fruits. Similarly, in animals including humans, growth is required before reproduction capability is attained.

Plants grow from seed to sapling to mature plants with flowers and fruits.
Animals grow to reach maturity before reproducing.
Humans give birth to young ones, which grow gradually.

Life Stages of Humans

Human life journey is divided into stages: infancy, childhood, adolescence, adulthood, and old age. Each stage brings specific changes.

Until about 10-12 years, changes are mostly in height and weight.
From 10 to 19 years, adolescence is a phase of rapid growth and development.
Adolescence prepares the body for adulthood and reproduction.

Physical Changes During Adolescence

Adolescence involves noticeable changes such as:

Increase in height and weight: Boys gain broader shoulders, girls develop breasts.
Voice changes: Boys experience hoarseness due to voice box growth (Adam's apple visible).
Facial skin changes: Acne or pimples due to oily secretions.
Growth of hair: In armpits, pubic region, boys develop facial and chest hair.

These physical signs that distinguish males and females but don't directly relate to reproduction are called secondary sexual characteristics.

Reproductive Changes

Internal changes happen in reproductive organs.
In girls, menstruation (period) begins, generally every 28-30 days, lasting 3-7 days.
Menstruation marks reproductive maturity and typically ends by age 45-55.
Myths and taboos around menstruation exist but should be replaced by scientific understanding.

Emotional and Behavioural Changes

Adolescence is also a time of strong emotions which affect behaviour:

Mood swings and strong emotions.
Increased sensitivity and creativity.
Sometimes involvement in social work and new interests.

Tip: Understanding emotions helps manage actions and make better decisions.

Healthy Lifestyle During Adolescence

Nutrition

Balanced nutrition is essential for this growth stage. Important nutrients include:

Food Sources	Nutrients	Functions
Milk, millets, curd, cheese, paneer	Calcium, Proteins, Fats	Bone growth, blood formation, strength, energy
Spinach, kidney beans, dried fruits (raisins, figs)	Iron	Prevents anemia and supports blood health

Personal Hygiene

Maintain cleanliness, especially in armpits and pubic region.
Girls should maintain menstrual hygiene using sanitary or reusable cloth pads.
Proper disposal of used pads is important for environment and health.

Physical Activities and Social Life

Regular exercise and sports keep body and mind healthy.
Social interaction should be respectful and responsible.
Responsible use of social media to avoid cyberbullying and misuse.

Avoid Harmful Substances

Say 'No' to tobacco, alcohol, and drugs as these cause addiction and severe health issues. Seek help if needed.

Role of Hormones

Hormones are chemicals that regulate growth, development, and emotional changes in adolescence. They prepare the body for reproduction and influence mood and behaviour.

Summary

Adolescence is between childhood and adulthood, approx. 10-19 years.
Marked by physical, emotional, and reproductive changes.
Secondary sexual characteristics help distinguish males and females.
Puberty is the stage where reproduction capability develops.
Balanced diet, hygiene, exercise, and responsible behaviour support healthy adolescence.
Say ‘No’ to harmful substances to protect health.

Textbook Questions & Answers ❓📚

1. Ramesh, an 11-year-old boy, developed pimples on his face. (i) What could be the reasons? (ii) How to get relief?

(i) Pimples appear due to increased oily secretions during adolescence which clog pores. (ii) Maintain facial hygiene, avoid oily food, and use gentle cleanser.

2. Which food group is better for adolescents and why?

Foods rich in proteins, calcium, iron, vitamins are best as they support growth, bone strength, and energy.

3. Unscramble the words: (i) nstmnoiaretu (ii) iceov xob (iii) urtypeb (iv) lahoclo and srugd

(i) Menstruation (ii) Voice box (iii) Puberty (iv) Alcohol and drugs

4. Is adolescence only physical changes? Explain.

No, adolescence also brings emotional and behavioural changes along with physical growth.

5. Check the correctness of: (i) Adolescents don’t need to worry about behavioural changes. (ii) Harmful substance once tried can be stopped anytime.

(i) Incorrect, behavioural changes are important and affect daily life. (ii) Incorrect, substance abuse can lead to addiction and is hard to stop.

6. What behavioural changes occur with mood swings in adolescence?

Besides mood swings, adolescents may show increased sensitivity, interest in social work, or creativity.

7. Suggest menstrual hygiene habits to friends.

Use clean sanitary pads, change regularly, dispose properly, and maintain cleanliness to avoid infections.

8. Mary and Manoj had a neck bump. Why different advice?

Mary's bump was due to thyroid issues needing iodine, Manoj’s bump (Adam’s apple) is normal growth in boys.

9. Categorize physical changes:

Observed only in boys	Observed only in girls	Common in boys and girls
Voice change, moustache, facial hair growth	Breast development	Pimples, hair growth in armpits and pubic region

10. Prepare a poster for a healthy adolescent lifestyle.

Eat balanced diet, maintain hygiene, exercise regularly, stay away from harmful substances, and be responsible.

6. Adolescence: A Stage of Growth and Change