Glossary
Adolescence
The transitional stage between childhood and adulthood, marked by physical and mental development.
Puberty
The period during adolescence when a person becomes capable of reproduction due to physical and hormonal changes.
Life Cycle
The stages of development a human goes through: childhood, adulthood, and old age.
Growth
An increase in mass and size of the body over time.
Hormones
Chemical substances secreted by endocrine glands that regulate body activities like growth, metabolism, and reproduction.
Endocrine Glands
Glands that release hormones directly into the bloodstream without using ducts.
Pituitary Gland
The “master gland” that controls the activities of other endocrine glands and regulates growth.
Thyroid Gland
A gland in the neck that produces thyroxine to control metabolism.
Thyroxine
A hormone made by the thyroid gland that controls the body’s metabolism and is essential for metamorphosis in frogs.
Goitre
A swelling in the neck caused by an enlarged thyroid gland, usually due to iodine deficiency.
Insulin
A hormone made by the pancreas that helps lower blood sugar levels.
Diabetes
A disease where the body does not produce enough insulin, causing high blood sugar.
Adrenal Glands
Small glands located on top of the kidneys that produce adrenaline and other important hormones.
Adrenaline
A hormone that prepares the body for ‘fight or flight’ during stressful situations.
Metamorphosis
A major change in body form during development, as seen in frogs and insects.
Secondary Sexual Characters
Physical features that develop during puberty (e.g., facial hair in boys, breast development in girls).
Menarche
The first menstrual flow in a girl’s life, marking the onset of reproductive capability.
Menopause
The natural stopping of menstruation in women, usually between ages 45-50.
Gametes
Sex cells (sperm in males, ova in females) involved in reproduction.
Sperms
Male gametes that fertilize the female ovum.
Ovum (plural: Ova)
The female gamete (egg cell) that can be fertilized by a sperm.
Zygote
A fertilized egg formed when a sperm and ovum fuse.
Sex Chromosomes
Chromosomes that determine the sex of a baby (XX for female, XY for male).
Personal Hygiene
Practices that help maintain health and prevent disease, like bathing and dental care.
Balanced Diet
A diet that contains appropriate amounts of all essential nutrients needed for good health.
Osteoporosis
A disease where bones become weak and brittle, often due to poor calcium intake.
Peer Pressure
The influence exerted by a peer group to encourage a person to change their attitudes, values, or behavior to conform.
‘Say No to Drugs’ Campaign
A movement encouraging young people to reject drug use and stay healthy.
Something To Know
A. Fill in the blanks.
- Endocrine glands release _________ into the blood stream.
Answer – hormones
- _________ is also known as the voice box.
Answer – Larynx
- Acne and pimples are common in adolescence due to increased production of _________ by the _________ glands.
Answer – Sebum, Sebaceous
- Deficiency of _________ reduces the absorption of calcium by the body.
Answer – Vitamin D
- _________ hormone is essential for metamorphosis to happen in a frog.
Answer – Thyroxine
- _________ are chromosomes other than the sex chromosomes.
Answer – Autosomes
B. Match the following.
- Ovary (a) adrenaline
- Pancreas (b) testosterone
- Adrenals (c) thyroxine
- Testes (d) insulin
- Thyroid (e) progesterone
Answer –
Column I | Column II |
1. Ovary | (e) Progesterone |
2. Pancreas | (d) Insulin |
3. Adrenals | (a) Adrenaline |
4. Testes | (b) Testosterone |
5. Thyroid | (c) Thyroxine |
C. Tick (✓) the correct option.
- The period of life, marked by rapid changes leading towards sexual maturity, is known as—
childhood
puberty
old age
adulthood
Answer – puberty
- The onset of menstruation, in a human female, is known as—
menarche
menopause
ovulation
adolescence
Answer – menarche
- The hormone, which controls the body’s response to stress, is known as— insulin
thyroxine
estrogen
adrenaline
Answer – adrenaline
- Out of following, the one that does not produce hormones, is the—
thyroid gland
pineal gland
sebaceous glands
testes
Answer – sebaceous glands
- The mineral, whose presence is essential for a tadpole to grow into a frog, is—
calcium
chlorine
selenium
iodine
Answer – iodine
D. Answer the following questions in brief:
- State the meaning of the term ‘Adolescence’.
Answer – Adolescence is the period of life between childhood and adulthood during which a person undergoes physical, emotional, and hormonal changes leading to sexual maturity.
- Define puberty. State the various factors which influence it.
Answer – Puberty is the stage when a child’s body develops into an adult body capable of reproduction. Factors influencing puberty include hormones, genetic makeup, nutrition, and health conditions.
- Why are endocrine glands known as ductless glands?
Answer – Endocrine glands are called ductless glands because they release their hormones directly into the bloodstream instead of through ducts.
- Why do tadpoles growing in iodine deficient waters fail to grow into frogs?
Answer – Iodine is necessary for the production of thyroxine hormone, which controls metamorphosis. Without iodine, tadpoles cannot produce enough thyroxine and fail to develop into frogs.
- How does the pituitary gland control the maturation of the gonads?
Answer – The pituitary gland secretes hormones like follicle-stimulating hormone (FSH) and luteinizing hormone (LH) that stimulate the development and functioning of the gonads (testes and ovaries).
- Women, above the age of fifty, are (generally) unable to give birth to children. Explain the reason for the same.
Answer – After the age of fifty, women typically undergo menopause, during which the ovaries stop releasing eggs and hormone production declines, making childbirth naturally impossible.
E. Answer the following questions.
- Enlist the changes which occur in males and females during puberty.
Answer – In males:
Voice deepens (Adam’s apple appears)
Growth of facial and body hair
Broadening of shoulders
Increase in muscle mass
Development of testes and production of sperms
In females:
Development of breasts
Widening of hips
Growth of body hair
Onset of menstruation
Maturation of ovaries and release of eggs
- Arun and his sister Arunima are both ‘teenagers’. Arunima observes a swelling on her neck, following which she visits a doctor. The doctor identifies it to be a deficiency disease and prescribes medicines accordingly, along with suggesting dietary modifications. A few months later, Arun observes a small protrusion on his throat and visits the doctor. However, the doctor assures him that it is a normal feature in boys of his age.
(a) Identify the disease Arunima was suffering from along with its cause.
Answer – Arunima was suffering from goitre, caused by a deficiency of iodine.
(b) Why do you think that no medication was prescribed for Arun?
Answer – Arun developed an Adam’s apple, a normal secondary sexual characteristic in boys during puberty, and it did not require any medical treatment.
- Discuss how the sex of the unborn child gets determined in human beings.
Answer – The sex of the unborn child is determined by the type of sperm that fertilizes the egg. If a sperm carrying an X chromosome fertilizes the egg (which always carries an X chromosome), the child will be female (XX). If a sperm carrying a Y chromosome fertilizes the egg, the child will be male (XY).
- Enlist the events that regularly occur in the female reproductive system, after the onset of puberty, until menopause.
Answer – Maturation and release of an egg (ovulation)
Thickening of the uterine lining to prepare for pregnancy
If fertilization does not occur, shedding of the uterine lining (menstruation)
Repetition of this cycle approximately every 28 days
- Highlight the importance of exercise and good personal hygiene during adolescence.
Answer – Exercise helps in proper physical growth, maintaining a healthy body weight, and reducing stress.
Good personal hygiene prevents infections, controls body odor, and promotes self-confidence during the rapid body changes of adolescence.
Value Based Question
Amit and Sumit are good friends since their childhood. Amit dreams of becoming a cricketer. He is extremely fond of junk food and loves to eat fries, pastas and burgers, both for his lunch as well as for his dinner. He avoids eating fruits and vegetables and drinking milk. Sumit feels very concerned about his friend. He warns him that he is ruining his health and may end up being an unhealthy adult instead of a sportsperson. He helps Amit to change his food habits so that he may fulfil his dream.
- State the values shown by Sumit.
Answer – Sumit shows the values of care, concern, friendship, responsibility, and a positive attitude towards healthy living.
- State the problems that Amit may face as an adult.
Answer – Amit may face problems like obesity, weak bones, lack of stamina, heart diseases, diabetes, and other lifestyle-related disorders.
- State the importance of fruits, vegetables and milk in one’s diet.
Answer – Fruits and vegetables provide essential vitamins, minerals, and fiber, which strengthen immunity and aid digestion.
Milk is a rich source of calcium and protein, necessary for strong bones, teeth, and muscle development.
- Arrange a ‘street play’ to highlight the importance of a ‘balanced and healthy diet’.
Answer – “Healthy Food, Healthy Life”
Scene 1: Show children eating only junk food and becoming tired, sick, and lazy.
Scene 2: A wise doctor explains the problems caused by junk food.
Scene 3: Children learn the importance of fruits, vegetables, grains, and milk.
Scene 4: After switching to a balanced diet, they become energetic, happy, and successful.
Conclusion: The group sings a catchy slogan like “Eat right, feel bright!” and encourage the audience to choose healthy living.
Something To Do
- Why is sex determination of the unborn foetus banned by the government? Visit a nearby hospital and discuss this issue with the resident doctor.
Answer – Sex determination is banned to prevent female foeticide, promote gender equality, and to protect the unborn girl’s right to life. It aims to correct the declining sex ratio in the country.
- Collect information about the — ‘Say No to Drugs’—campaign and prepare a display board using the details of this information.
Answer – The ‘Say No to Drugs’ campaign raises awareness about the harmful effects of drug abuse. It educates youth about staying healthy, resisting peer pressure, and making positive life choices. Posters, slogans like “Life is precious, say no to drugs”, and real-life stories are often used for awareness.
- There are various myths related to changes in the body that occur during adolescence. Make a list of such myths and discuss in your class why these myths should not be believed.
Here is one: ‘A menstruating girl is impure and hence, should not enter the kitchen.’
Answer – Myth: A menstruating girl is impure and should not enter the kitchen.
Myth: Acne means you are dirty.
Myth: Boys must be taller than girls.
Myth: Mood swings mean bad character.
Myth: Talking about puberty is shameful.
These myths should not be believed because they are based on ignorance, not science. Puberty-related changes are natural, and understanding them helps build a healthy mindset.
- Find out the sex ratio of your state. Compare it with the state having the best ratio and discuss in class, the probable reasons for the observed values of the ratios in both the states.
Answer – Kerala (Best sex ratio): 1084 females per 1000 males.
Haryana (Earlier had poor sex ratio): Around 922 females per 1000 males.
Discussion:
Better education, awareness, and women empowerment policies improve the sex ratio, while gender biases and preference for sons lower it.
- “Adolescence: A unique phase marked by concerns and challenges.” Have a group discussion on the above mentioned topic.
Answer – During adolescence, individuals experience physical, emotional, and mental changes. Challenges include peer pressure, career choices, emotional ups and downs, and body image concerns. Proper guidance, support, and self-confidence help adolescents handle this unique phase positively.
- Search for the following in the word search puzzle given below.
- Period of transition from childhood to adulthood.
- Reaching the age of sexual maturity.
- Gland which releases the growth hormone.
- Disease caused due to deficiency of a pancreatic hormone.
- Reproductive organs.
- This hormone controls the metabolic rate.
- Voice box.
- Disease caused by deficiency of calcium and Vitamin D.
- Onset of puberty in females.
- Transition of tadpole into a frog.
- Stress regulating hormone.
- Male gamete.
- Chromosomes other than the sex chromosomes.
- Hormone produced by the pancreas.
Answer – Adolescence
Puberty
Pituitary
Diabetes
Gonads
Thyroxine
Larynx
Rickets
Menarche
Metamorphosis
Adrenaline
Sperm
Autosomes
Insulin
Additional Questions and Answers – 01
Short Answer Questions (2–3 lines)
Question – What are secondary sexual characters?
Answer: Traits that distinguish males and females but are not directly involved in reproduction, such as a deeper voice in boys and breast development in girls.
Question – Name two changes that occur in girls during puberty.
Answer: Enlargement of breasts and widening of hips.
Question – Which gland is called the ‘master gland’ and why?
Answer: The pituitary gland is called the master gland because it controls the functioning of other endocrine glands.
Question – Mention two physical changes seen in boys during adolescence.
Answer: Broadening of shoulders and growth of facial hair.
Question – Define menarche and menopause.
Answer: Menarche is the first menstruation in females; menopause is the permanent stopping of menstruation around 45–50 years of age.
Long Answer Questions (5–8 lines)
Question – Explain the role of hormones in the human body.
Answer: Hormones are chemical messengers secreted by endocrine glands. They regulate growth, metabolism, sexual development, stress response, and many other bodily functions.
Question – What is the significance of maintaining personal hygiene during adolescence?
Answer: Good personal hygiene prevents infections like acne and fungal infections, boosts self-esteem, and promotes overall health during a time when the body undergoes rapid changes.
Question – Discuss the effects of stress and how adolescents can cope with it.
Answer: Stress can lead to anxiety, poor academic performance, and health issues. Adolescents can manage stress through exercise, proper sleep, sharing feelings with trusted adults, and time management.
Question – Explain the term metamorphosis with an example.
Answer: Metamorphosis is a biological process by which an animal physically develops after birth. For example, a tadpole transforming into a frog.
Question – How does diet affect growth during adolescence?
Answer: A balanced diet provides essential nutrients like proteins, vitamins, and minerals that are crucial for proper physical and mental development during adolescence.
Multiple Choice Questions (MCQs)
Question – Which of the following glands controls blood sugar levels?
(a) Thyroid
(b) Pancreas
(c) Pituitary
(d) Adrenal
Answer: (b) Pancreas
Question – Which hormone is responsible for the development of secondary sexual characters in boys?
(a) Estrogen
(b) Progesterone
(c) Testosterone
(d) Insulin
Answer: (c) Testosterone
Question – At what age does adolescence typically begin?
(a) 2 years
(b) 10 years
(c) 25 years
(d) 60 years
Answer: (b) 10 years
Question – The hormone responsible for regulating metabolism is:
(a) Insulin
(b) Thyroxine
(c) Adrenaline
(d) Testosterone
Answer: (b) Thyroxine
Question – Which of the following organs is NOT a part of the endocrine system?
(a) Ovary
(b) Testes
(c) Lungs
(d) Adrenal
Answer: (c) Lungs
True/False Questions
Question – The pituitary gland is located in the abdomen.
Answer: False (It is located at the base of the brain.)
Question – Menopause usually occurs in females around 45–50 years of age.
Answer: True
Question – Adolescents should avoid eating fresh fruits and vegetables.
Answer: False
Question – Puberty causes physical and emotional changes in adolescents.
Answer: True
Question – Sebaceous glands are responsible for the secretion of sweat.
Answer: False (Sebaceous glands secrete oil, sweat glands secrete sweat.)
Question – Thyroxine deficiency can cause goitre.
Answer: True
Additional Questions and Answers – 02
Short Answer Questions (1-2 marks)
Question – What is adolescence?
Answer: Adolescence is the transitional stage between childhood and adulthood, marked by physical and mental development (ages 12–18).
Question – Define puberty.
Answer: Puberty is the period of rapid physical and psychological changes leading to sexual maturity.
Question – Name two hormones responsible for changes in boys and girls during puberty.
Answer: Boys: Testosterone; Girls: Estrogen and Progesterone.
Question – What is menarche?
Answer: Menarche is the first menstrual flow in girls at puberty.
Question – Which gland is called the “master gland”?
Answer: The pituitary gland (controls other endocrine glands).
Question – What determines the sex of a child?
Answer: The sex chromosome from the sperm (X or Y) fertilizing the egg (always X).
Question – Why does voice change during puberty?
Answer: The larynx (voice box) grows, and vocal cords lengthen and thicken, deepening the voice.
Question – What is Adam’s apple?
Answer: A protruding larynx in males due to growth during puberty.
Question – Name one nutritional deficiency that affects bone health in adolescents.
Answer: Calcium or Vitamin D deficiency.
Question – What is the role of thyroxine in frogs?
Answer: It regulates metamorphosis (tadpole to adult frog).
Long Answer Questions (5 marks)
Question – Explain the physical changes during puberty in boys and girls.
Answer: Boys: Growth of facial/pubic hair, deepening voice, testes produce sperm.
Girls: Breast development, onset of menstruation, widening of hips.
Common: Height spurt, sweat/oil gland activity, hormonal changes.
Question – Describe the menstrual cycle. What are menarche and menopause?
Answer: Cycle: Monthly shedding of uterine lining (3–6 days) if no fertilization occurs.
Answer: Menarche: First menstruation (11–13 years).
Menopause: End of menstruation (45–50 years).
Question – How do endocrine glands regulate growth and development?
Answer: Pituitary: Releases growth hormone.
Thyroid: Thyroxine regulates metabolism.
Adrenals: Control stress response.
Gonads (testes/ovaries): Produce sex hormones.
Question – Why is a balanced diet crucial for adolescents?
Answer: Supports rapid growth, bone health (calcium), energy, and prevents deficiencies (iron, vitamins).
Poor nutrition leads to obesity, osteoporosis, or anemia.
Question – Discuss the harmful effects of drug abuse in adolescence.
Answer: Health risks (organ damage, mental illness), addiction, poor academic performance, and social problems.
MCQs (1 mark each)
Question – Adolescence ranges from:
- a) 5–10 years
- b) 12–18 years ✅
- c) 20–30 years
Question – Puberty in girls starts at:
- a) 8–10 years ✅
- b) 12–14 years
- c) 15–17 years
Question – Which hormone is NOT involved in puberty?
- a) Insulin ✅ (regulates blood sugar)
- b) Testosterone
- c) Estrogen
Question – Adam’s apple is due to growth of:
- a) Larynx ✅
- b) Lungs
- c) Thyroid
Question – Sex determination depends on:
- a) Mother’s egg
- b) Father’s sperm ✅
- c) Both equally
True/False (1 mark each)
Question – Adolescents need less calcium than adults.
Answer: False (Bone growth requires more calcium).
Question – Menarche marks the end of reproductive life.
Answer: False (Menopause does).
Question – Thyroxine is essential for frog metamorphosis.
Answer: True.
Question – Girls grow taller than boys after puberty.
Answer: False (Boys usually grow taller).
Question – Personal hygiene is unimportant during adolescence.
Answer: False (Critical to prevent infections).