Have you noticed that your school shoes stopped fitting much faster this year than they did in Class 4? Or that a friend who was the shortest in the class photo two years ago is now taller than you? These are not random accidents. They are signs that your body has entered one of the busiest building phases of your whole life. In the new NCERT textbook Curiosity, this phase is explored in the chapter on adolescence, and these notes re-teach the whole topic from scratch in simple language, with everyday examples, practice questions and a quick self-test at the end.
The best part about this chapter is that it is not just something to memorise for an exam. It explains what is happening inside you, right now. Understanding it makes the changes far less confusing and helps you take care of your own health with confidence.
What You’ll Learn
- Growth: from a baby to an adult
- What adolescence and puberty actually mean
- Physical changes during puberty
- Hormones: the body’s chemical messengers
- The menstrual cycle and menstrual hygiene
- Eating right during the growth spurt
- Physical activity, sleep and screen time
- Personal hygiene that matters more now
- Emotional and social changes
- Common myths, corrected
- Saying no to harmful substances
- Textbook Questions ki Taiyari
- Extra Practice (8 Q&A)
- Self-Assessment
Growth: from a baby to an adult
Every living thing that reproduces has to grow up first. A mango seed cannot produce mangoes the week it sprouts. It must first become a sapling, then a young tree, and only after several years does it flower and form fruit. Animals follow the same rule. A newly hatched chick cannot lay eggs; a calf cannot have a calf of its own. Growing to maturity is a compulsory stage, not an optional one.
Human beings follow this pattern too, just over a longer timeline. Scientists usually describe human life in broad stages: infancy (the first year or so), childhood, adolescence (किशोरावस्था), adulthood and old age. Each stage has its own pace of change. Infancy is fast, childhood is slow and steady, and then adolescence speeds everything up again.
A useful way to picture this is a height-versus-age graph. From about age 2 to age 9, the line climbs gently — roughly 5 to 6 cm a year for most children. Then, somewhere between ages 10 and 14, the line suddenly gets steeper. A child may add 8 to 10 cm in a single year. Later, in the late teens, the line flattens out and finally stops rising. That steep middle part is called the growth spurt (वृद्धि उछाल).
What adolescence and puberty actually mean
Adolescence is the whole stage of life between childhood and adulthood. For most people it covers roughly ages 10 to 19, though the exact years differ from person to person. During this stage the body, the brain and even the way a person thinks about the world all change together.
Puberty (यौवनारंभ) is a narrower word. It refers specifically to the period within adolescence when the body matures and becomes capable of reproduction. Puberty usually begins earlier in girls (around ages 9 to 13) than in boys (around ages 11 to 15), which is exactly why the girls in a Class 7 line-up are often noticeably taller than the boys for a couple of years — and why the boys catch up later.
Two ideas are worth holding on to here. First, adolescence is a normal, healthy, universal stage — every single adult you know has been through it. Second, its timing varies enormously. Starting earlier or later than a classmate says nothing at all about health, ability or worth.
Physical changes during puberty
Some changes happen to everyone during puberty, and some are specific to girls or to boys. The features that begin to distinguish males from females at this stage — such as facial hair in boys and breast development in girls — are together called secondary sexual characters (गौण लैंगिक लक्षण). Let us take the shared changes first.
Increase in height. This is the change students notice first. The long bones of the arms and legs grow rapidly, which is why hands and feet often seem to grow “out of proportion” for a while. They are simply a step ahead; the rest of the body catches up. Height increase slows down and finally stops in the late teens, once the growing regions in the bones close.
Change in body shape and weight. Muscles and bones become heavier, so weight rises along with height. In boys, the shoulders generally broaden; in girls, the region around the hips generally widens. Both are normal patterns, not a competition.
Changes in skin. Oil glands in the skin become more active, which is why pimples and acne are so common at this age — especially on the face, chest and back. Acne is a plumbing problem, not a cleanliness failure. Washing the face gently twice a day helps; scrubbing hard makes it worse.
Growth of body hair. Hair appears in the underarm and pubic regions in both girls and boys. Boys additionally begin to grow facial hair.
Change in voice. The voice box, or larynx (स्वरयंत्र), grows larger. In boys it grows enough to be seen from outside as a small bump at the front of the throat, commonly called the Adam's apple. The growth is greater in boys, which is why a boy’s voice deepens noticeably and often “cracks” for a few months while the vocal cords adjust. Girls’ voices deepen too, but by a smaller amount, so the change is less obvious.
Maturing of reproductive organs. The reproductive organs complete their development, so that the body becomes capable of reproduction. In girls, this includes the start of the menstrual cycle, which we look at separately below.
Question intent: Aarav’s height was recorded on each birthday — 128 cm at age 9, 134 cm at 10, 143 cm at 11, 152 cm at 12, 157 cm at 13 and 159 cm at 14. In which year was his growth fastest, and what does that tell us?
Working: Find the increase for each year by subtracting.
9→10: 134 − 128 = 6 cm
10→11: 143 − 134 = 9 cm
11→12: 152 − 143 = 9 cm
12→13: 157 − 152 = 5 cm
13→14: 159 − 157 = 2 cm
Answer: The fastest growth happened between ages 10 and 12, when he gained 9 cm in each year. This is his growth spurt. The much smaller gains at 13 and 14 show the spurt is ending and his height is beginning to level off. His total gain from age 9 to 14 was 159 − 128 = 31 cm, and 18 cm of that came in just those two spurt years — over half of all his growth in that period.
Hormones: the body’s chemical messengers
What actually triggers all these changes at roughly the same time? The answer is a group of chemicals called hormones (हॉर्मोन).
Hormones are chemical messengers made by special organs called endocrine glands (अंतःस्रावी ग्रंथियाँ). Unlike a gland that pours its liquid out through a tube — the way a sweat gland releases sweat onto the skin — an endocrine gland releases its hormone straight into the blood. The blood then carries it all over the body.
Here is a helpful comparison. Think of the nervous system as a phone call: fast, direct, one specific listener. Hormones are more like an announcement on a railway station loudspeaker: the message travels everywhere, but only the passengers waiting for that particular train actually respond to it. The body part that a particular hormone acts upon is called its target site or target organ (लक्ष्य अंग). Every other organ simply ignores the message.
The gland that starts the whole process is the pituitary gland (पीयूष ग्रंथि), a small gland at the base of the brain. At the right stage of life it releases hormones that instruct other glands to become active. Those glands then release the hormones responsible for the changes of puberty. The two main ones are testosterone (टेस्टोस्टेरोन), made by the testes in boys, and oestrogen (एस्ट्रोजन), made by the ovaries in girls. Testosterone is behind the deeper voice, facial hair and broader shoulders; oestrogen is behind breast development and the start of the menstrual cycle. Both boys and girls actually make small amounts of each, just in very different quantities. Because these signals travel in the blood and reach the whole body, several different changes — height, voice, skin, body hair — begin at around the same time rather than one by one.
Some other glands worth knowing at this level:
- Thyroid gland (थायरॉइड ग्रंथि) — in the neck; its hormone controls the rate at which the body uses energy. It needs iodine, which is why iodised salt matters.
- Pancreas (अग्न्याशय) — releases insulin, which keeps the amount of sugar in the blood under control.
- Adrenal glands (अधिवृक्क ग्रंथियाँ) — sit above the kidneys and release the hormone that makes your heart race when you are startled.
The menstrual cycle and menstrual hygiene
One of the clearest signs that puberty has begun in girls is the start of menstruation (मासिक धर्म). This is a normal, healthy body process, and both girls and boys should understand it — partly because it is science, and partly because understanding it is what stops teasing and embarrassment.
In simple terms: once the reproductive organs mature, the inner lining of the uterus thickens each month, getting ready in case a pregnancy occurs. When there is no pregnancy, that lining is not needed, so it breaks down and leaves the body through the vagina along with a small amount of blood. This flow usually lasts about three to five days. The whole repeating pattern is called the menstrual cycle, and it takes roughly 28 days, though anywhere from about 21 to 35 days is common and normal.
The first period is called menarche, and it usually happens between ages 10 and 15. In the first year or two the cycle is often irregular — one month it may come after 25 days, the next after 40. This is expected while the body settles into its rhythm. The menstrual cycle does not continue for life: it stops permanently at around 45 to 50 years of age, and this stopping is called menopause (रजोनिवृत्ति). So the reproductive phase in women has a clear beginning (menarche) and a clear end (menopause).
Menstrual hygiene matters for health and comfort:
- Use a clean sanitary pad or cloth and change it every four to six hours, even on light-flow days.
- Wash hands with soap before and after changing.
- Bathe normally — there is no reason to avoid a bath during periods.
- Wrap used pads in paper and put them in a dustbin. Never flush them.
- Keep eating and drinking normally; iron-rich foods such as green leafy vegetables, jaggery and dates are useful.
- Mild cramps are common. A warm compress and light movement usually help. Severe pain, very heavy bleeding, or a cycle that stays highly irregular after two years is worth discussing with a parent and a doctor.
Girls should not be kept out of school, sport or ordinary daily life during periods. Missing classes every month adds up to weeks of lost learning in a year, for a reason that is not a health reason at all.
Eating right during the growth spurt
A body that is adding several centimetres of bone and a good deal of muscle in a single year is running a construction site. Construction sites need materials, and food is where those materials come from. This is why nutrition during adolescence matters more than at almost any other stage.
A balanced plate at this age should include:
- Proteins — the building material for muscles and tissues. Dal, rajma, chana, milk, curd, paneer, eggs, fish, chicken, soya, groundnuts.
- Carbohydrates and fats — the fuel. Roti, rice, potato, oil, ghee in sensible amounts. Skipping these leaves you tired by the fourth period.
- Calcium and vitamin D — for bones that are lengthening fast. Milk, curd, ragi, sesame seeds, and about fifteen minutes of morning sunlight.
- Iron — for making blood. Green leafy vegetables, jaggery, dates, whole grains. Adolescent girls need extra iron because of menstrual blood loss. Eating a vitamin-C food such as amla, guava, orange or lemon along with an iron food helps the body absorb the iron better.
- Vitamins, minerals and fibre — fruits and vegetables of different colours.
- Water — roughly 8 to 10 glasses a day, more in summer or after sport.
What to keep occasional rather than daily: packaged chips, deep-fried snacks, sweet fizzy drinks and instant noodles. These are high in energy but low in the proteins, vitamins and minerals a growing body actually needs — they fill the stomach without supplying the materials. Nutritionists call this “empty calories”.
Question intent: Meera’s usual lunch is two plain parathas and a packet of chips, with a cold drink. Identify what is missing and suggest a better version without changing the amount of food much.
What is present: Carbohydrates and fat, from the parathas and chips — energy is covered.
What is missing: Protein (no dal, curd, egg or paneer), calcium, iron, vitamins and fibre. The cold drink adds sugar but no nutrients.
Improved tiffin: Keep the two parathas but stuff one with paneer or mashed dal. Replace the chips with a small bowl of curd and a few slices of cucumber and carrot. Replace the cold drink with water, and add an orange or a guava. Why it works: the paneer or dal supplies protein for muscle growth, curd adds calcium for the lengthening bones, the vegetables add fibre and vitamins, and the citrus fruit helps the body absorb iron from the meal.
Physical activity, sleep and screen time
Food supplies the material, but the body still needs the right conditions to use it well.
Physical activity. About an hour of moderate activity a day is a good target at this age — cycling, running, kabaddi, football, badminton, skipping, dancing, swimming, even brisk walking. Exercise strengthens bones and muscles, keeps the heart efficient, improves sleep, and reliably lifts mood. Notice that games with friends deliver exercise and social connection in the same hour, which is a good bargain.
Sleep. Adolescents need roughly 8 to 10 hours of sleep. This is not laziness — a great deal of growth and repair happens during deep sleep, and the brain uses sleep to file away what was learnt during the day. Studying until 1 a.m. on four hours of sleep usually loses more than it gains.
Screen time. Long hours on a phone or computer eat into the two things above: the time that would have gone into playing, and the sleep that late-night scrolling pushes back. Screens also strain the eyes. A simple habit that helps is the 20-20-20 rule — every 20 minutes, look at something about 20 feet away for 20 seconds. Putting the phone away an hour before bed makes falling asleep noticeably easier.
Personal hygiene that matters more now
During puberty the sweat glands and oil glands become much more active. Sweat itself has almost no smell; body odour appears when bacteria living on the skin break sweat down. That is why hygiene habits which were optional in Class 4 become genuinely necessary now.
- Bathe daily with soap, paying attention to the underarms, feet and groin.
- Wear clean, dry, ideally cotton clothes; change underclothes every day.
- Wash the face gently twice a day. Do not squeeze pimples — it can leave scars and spread infection.
- Keep nails short and clean; wash hands before meals and after using the toilet.
- Dry the feet properly after a bath, especially between the toes, to avoid fungal infection.
- Brush twice a day; the gums can become more sensitive at this age.
Emotional and social changes
Adolescence changes more than height and voice. Hormones also affect mood, and at the same time the brain itself is reorganising — the regions that handle planning, judgement and self-control are still under construction well into the late teens. Put those together and a lot of familiar experiences make sense.
Common changes at this stage include:
- Mood swings. Feeling cheerful, irritated and low within the same afternoon, sometimes for no clear reason.
- Self-consciousness. Worrying about height, weight, skin or voice, and assuming everyone is noticing. Usually they are busy worrying about themselves.
- Friends matter more. The opinion of the peer group starts to carry unusual weight — which is powerful when friends encourage good habits and risky when they do the opposite.
- Wanting independence. A desire to make your own decisions, which can create friction with parents who are used to making them for you.
- New curiosity and stronger feelings. Including attraction towards others. Feeling this is normal; how a person behaves is what deserves thought.
Three practical habits help more than any amount of advice: talk to a parent, teacher, elder sibling or counsellor instead of bottling things up; move, because exercise and sleep genuinely steady the mood; and be kind, since everyone around you is going through their own version of the same thing. Teasing someone about acne, height, weight, a cracking voice or periods can hurt far longer than the teaser imagines. If low mood, constant worry or hopelessness lasts for weeks, that is a signal to speak to a trusted adult — the same way you would about a fever that would not go.
Common myths, corrected
Plenty of confident-sounding statements float around about this stage of life. Here are some of the common ones, and what the science actually says.
- Myth: Girls should not bathe, cook or exercise during periods. Fact: Menstruation is a normal process. Bathing and normal activity are healthy and there is no scientific reason to restrict them.
- Myth: Pimples appear because a person is dirty. Fact: Acne is caused by hormone-driven oil glands blocking skin pores. Gentle washing helps; harsh scrubbing irritates the skin further.
- Myth: A boy who is short at 13 will be a short adult. Fact: Growth spurts start at different ages. Many boys grow substantially between 14 and 18.
- Myth: Eating more oily food makes you grow taller and stronger. Fact: Growth needs protein, calcium, iron and vitamins. Extra oil mostly adds energy the body does not need.
- Myth: Skipping meals is a smart way to control weight. Fact: During the growth spurt, skipping meals starves the body of building material and usually leads to overeating later. Balanced meals plus activity are the sensible route.
- Myth: Everyone else has this figured out. Fact: Almost every classmate is quietly wondering whether they are normal. They are.
Saying no to harmful substances
Adolescence is exactly the stage when someone may first offer a young person tobacco, gutka, alcohol or other harmful substances — often a slightly older acquaintance, often framed as a dare or as proof of being grown-up.
The science is not complicated. Tobacco in any form damages the lungs, stains the teeth, and is strongly linked to mouth and lung cancer. Alcohol affects the liver and the developing brain, and the adolescent brain — still being wired — is more vulnerable than an adult’s. These substances also cause dependence, which is what makes “just once” a genuinely bad bet.
A refusal does not need to be a speech. “No thanks, I don’t”, said plainly and repeated once, works better than an explanation. Walking away is always available, and telling a parent or teacher afterwards is a sensible move, not a childish one. The friends worth keeping are the ones who accept the first “no”.
Textbook Questions ki Taiyari
The exercise at the end of this chapter tests a handful of recurring ideas. Below, each question intent has been reworded in our own words, with a complete original explanation. Work through the reasoning rather than memorising the wording.
1. Why is adolescence described as a stage of both growth and change?
Because two different things happen at once. Growth refers to the increase in size — height, weight, muscle and bone. Change refers to the transformations in the way the body works and in how a person thinks and feels: the voice deepens, the skin becomes oilier, the reproductive organs mature, moods fluctuate and social relationships shift. A person could grow taller without maturing, or mature emotionally without growing much taller. In adolescence, both processes run together, which is why the chapter title uses both words.
2. How do hormones cause so many different changes at the same time?
Hormones are chemical messengers produced by endocrine glands, and these glands release them directly into the blood rather than through a duct. Since blood circulates through the entire body, a hormone reaches many organs at once. Each target organ that is built to respond to that hormone begins its own change. So a single set of signals from the pituitary gland can set off height increase, voice change, skin changes and the maturing of reproductive organs during the same period of life — they look coordinated because they share one trigger.
3. Why do girls in a Class 7 classroom often appear taller than boys of the same age?
Puberty, and with it the growth spurt, generally begins a year or two earlier in girls than in boys. So at ages 11 to 13, many girls are already in the steep part of their growth curve while many boys have not yet entered theirs. This creates a temporary height gap. The boys usually begin their own spurt a little later and continue growing for longer, so the gap typically closes and often reverses by the later teens. The difference is a matter of timing, not of one group growing more than the other.
4. Explain the menstrual cycle briefly and state why menstrual hygiene is important.
After the reproductive organs mature, the lining of the uterus thickens each month in preparation for a possible pregnancy. If pregnancy does not occur, this lining is shed and passes out of the body along with a small amount of blood, over about three to five days. The cycle then repeats, typically at intervals of around 28 days. Hygiene matters because the flow needs to be managed with a clean absorbent material that is changed every four to six hours; leaving a pad or cloth in place too long allows bacteria to multiply and can cause infection or rashes. Washing hands, bathing normally, and disposing of used pads in a covered bin complete good practice. Restricting a girl’s food, movement, bathing or schooling during her period has no scientific basis.
5. What should an adolescent’s diet contain, and why?
It should be balanced, and it should be generous, because the body is building new tissue quickly. Proteins from dal, milk, curd, paneer, eggs, nuts or fish supply the material for muscles and tissues. Calcium from milk products and ragi supports bones that are lengthening rapidly. Iron from green leafy vegetables, jaggery and whole grains is needed to make blood, and adolescent girls need more of it because of monthly blood loss. Carbohydrates and fats supply energy for a body that is both growing and active. Fruits and vegetables supply vitamins, minerals and fibre, and vitamin-C rich fruits also improve iron absorption. Plenty of water is needed throughout. Highly processed, deep-fried and sugary items should stay occasional, since they provide energy without the nutrients growth requires.
6. Why do many adolescents experience mood swings, and what can help?
Two reasons work together. First, the hormonal changes of puberty influence the brain regions involved in emotion. Second, the parts of the brain responsible for planning and self-control are still developing during these years. On top of the biology, adolescents face new academic and social pressures. The result is emotions that feel stronger and shift faster than before. What helps: talking to a parent, teacher or counsellor; regular physical activity; adequate sleep of eight to ten hours; and a realistic expectation that this is a normal phase. Persistent sadness or anxiety lasting several weeks is a reason to seek help from a trusted adult or a professional.
7. Why should adolescents avoid tobacco and alcohol?
Tobacco, whether smoked or chewed, damages the lungs and mouth and is strongly associated with cancer of the mouth, throat and lungs. Alcohol harms the liver and interferes with a brain that is still developing during adolescence. Both create dependence, which means the body starts demanding more, so quitting later becomes much harder than refusing at the start. Because the adolescent body and brain are still being built, the damage from these substances tends to be greater than the same exposure in an adult. Refusing clearly, leaving the situation, and informing a trusted adult are practical responses.
8. A classmate is teased about a cracking voice. How would you respond, and what is the science behind it?
The science first: during puberty the larynx, or voice box, enlarges and the vocal cords lengthen. The growth is greater in boys, so their voice deepens noticeably. While this change is in progress, the vocal cords are still adjusting to their new size, so the voice can break or crack unpredictably for a few months. It settles on its own; nothing is wrong. As for the response — the honest thing is to not join in and to say so, and to explain to the group that this happens to almost every boy, just at different ages. Anyone teasing today is quite likely to be in the same position in a few months.
Extra Practice
Try each one on paper first, then open the answer.
Q1. Define adolescence and puberty in one line each, and state how they differ.
Answer: Adolescence is the stage of life between childhood and adulthood, roughly ages 10 to 19. Puberty is the phase within adolescence during which the body matures and becomes capable of reproduction. The difference: adolescence is the longer overall life stage, while puberty is the shorter physical-maturing phase inside it, and puberty ends earlier than adolescence does.
Q2. A student’s height goes from 140 cm at age 11 to 152 cm at age 12, and then to 156 cm at age 13. Calculate the yearly increases and say what they indicate.
Answer: From 11 to 12: 152 − 140 = 12 cm. From 12 to 13: 156 − 152 = 4 cm. The very large 12 cm gain shows the growth spurt was at its peak during that year, and the much smaller 4 cm gain that follows indicates the spurt is slowing down. Total gain over two years = 156 − 140 = 16 cm, of which 75% came in the first year.
Q3. Name the gland that controls the start of puberty and state where it is located.
Answer: The pituitary gland. It is a small gland located at the base of the brain. It releases hormones that instruct other endocrine glands to become active, which is what sets the changes of puberty in motion.
Q4. Why is an endocrine gland different from a sweat gland?
Answer: A sweat gland releases its product through a duct — a tube that carries the sweat out onto the surface of the skin. An endocrine gland has no such duct; it releases its hormone directly into the blood, which then carries the hormone to target organs throughout the body. That is why endocrine glands are also called ductless glands.
Q5. Adolescent girls are advised to eat more iron-rich food than adolescent boys. Give the reason, and name three such foods.
Answer: Iron is needed to make haemoglobin in blood. Adolescent girls lose a small amount of blood every month during menstruation, so they need extra iron to replace it and avoid anaemia. Three iron-rich foods: green leafy vegetables such as spinach, jaggery, and dates. Whole grains and rajma are also good sources. Eating a vitamin-C food such as guava or lemon with the meal helps the body absorb the iron.
Q6. Explain why the voice changes during puberty, and why the change is more noticeable in boys.
Answer: The larynx, or voice box, grows larger during puberty and the vocal cords inside it become longer and thicker. Longer, thicker vocal cords vibrate more slowly, which produces a deeper sound. The larynx grows more in boys than in girls, so a boy’s voice deepens much more noticeably. During the months when the cords are still adjusting to their new size, the voice may crack unpredictably. Girls’ voices also deepen slightly, but by a smaller amount, so the change usually goes unnoticed.
Q7. Give three reasons why sleep is especially important during adolescence.
Answer: First, a great deal of growth and tissue repair takes place during deep sleep, and the adolescent body is growing rapidly. Second, the brain uses sleep to consolidate what was learnt during the day, so adequate sleep directly supports studying. Third, sleep steadies mood — short sleep makes the emotional ups and downs of this age noticeably worse and reduces concentration in class. Eight to ten hours is the recommended range.
Q8. Someone claims that acne can be cured by scrubbing the face hard several times a day. Evaluate this claim.
Answer: The claim is incorrect. Acne is not caused by dirt on the surface of the skin; it happens because hormones make the oil glands in the skin more active, and the extra oil, along with dead skin cells, blocks the pores. Scrubbing hard removes the skin’s protective layer, irritates and inflames it, and can make the acne worse and spread infection. The sensible approach is washing gently with a mild cleanser twice a day, not squeezing pimples, drinking enough water, and seeing a doctor if the acne is severe.
Q9. An older cousin offers a Class 7 student a cigarette and says “one won’t do anything”. Write two scientific reasons to refuse and one practical way to say no.
Answer: Scientific reasons: (i) tobacco smoke damages lung tissue and is strongly linked to cancer of the mouth, throat and lungs; (ii) tobacco causes dependence, so the body starts to demand more and stopping later becomes far harder than refusing now — which is exactly why “just one” is a misleading argument. A practical refusal: say “No thanks, I don’t” plainly, repeat it once if needed, walk away, and tell a parent or teacher afterwards.
Q10. Two students of the same age differ in height by 15 cm. Their classmate concludes that the shorter one is unhealthy. Is this a valid conclusion? Explain.
Answer: No, it is not valid. Puberty and the growth spurt begin at different ages in different people — anywhere from about 9 to 15. A student who has already had their spurt will be much taller than a same-age classmate whose spurt has not yet begun, even though both are perfectly healthy. Height also depends on inherited family traits. A difference in height at one moment in time gives no information about health; nutrition, activity level, sleep and medical check-ups do.
Self-Assessment
Five quick questions. Write your answers, then check.
- Which gland at the base of the brain triggers the start of puberty?
- Endocrine glands release their hormones into which part of the body?
- Roughly how many days does a typical menstrual cycle last?
- Name one nutrient adolescent girls need in larger amounts, and say why.
- State one reason the voice cracks in boys during puberty.
Show answers
- The pituitary gland.
- Directly into the blood (they have no ducts).
- About 28 days, though roughly 21 to 35 days is also normal.
- Iron — to replace the blood lost during menstruation and prevent anaemia. (Calcium and protein are also needed in higher amounts during the growth spurt.)
- The larynx is enlarging and the vocal cords are still adjusting to their new, longer size, so the voice breaks until the change is complete.
Kaizen Close
This chapter is one of the few in the syllabus where the answers are useful the same evening you learn them. You cannot make yourself grow faster, but you can control what you eat, how much you sleep, how much you move, and how you treat classmates who are going through the same changes on a different schedule.
So pick one small thing this week — an extra glass of milk, lights out fifteen minutes earlier, twenty minutes of play outdoors, or simply not laughing when someone’s voice cracks. One small improvement, repeated, is what kaizen means. Start your Growth Log today and let the two weeks show you the rest.