Chapter 3: Health: The Ultimate Treasure (Biology)

• Communicable: cold and flu (virus), typhoid (bacteria) and chickenpox (virus).
• Non-communicable: diabetes and asthma.

Communicable: cold and flu, typhoid, chickenpox. Non-communicable: diabetes, asthma.

Asthma and diabetes do not spread from person to person. Typhoid and measles are caused by germs.

(b) (ii) and (iii)

(i) The school should:

• ask students and staff with fever, cough or sneezing to stay at home until they recover;
• remind everyone to cover coughs and sneezes and to wash hands often with soap;
• keep classrooms well ventilated and clean shared surfaces such as desks, door handles and taps;
• inform parents, and take advice from the local health centre.

(ii) Speak gently: "You don't look well. Maybe you should tell the teacher and rest at home; you'll get better faster." Offer your handkerchief or a mask, and share the class notes later. Avoid teasing, or moving away in a way that embarrasses them.

(iii) To protect yourself and others:

• wash your hands often, and do not touch your eyes, nose or mouth;
• wear a mask if advised, and keep some distance;
• do not share bottles, cups or handkerchiefs;
• eat well and sleep enough;
• if you get symptoms, stay at home.

(i) Ask sick students to stay home; promote hand-washing and covering coughs; ventilate and clean classrooms. (ii) Kindly suggest they tell the teacher and rest, and offer help. (iii) Wash hands, avoid touching your face, don't share items, wear a mask, stay home if ill.

(i)

• Before: read the health advisory, and see a doctor (who may advise medicines to prevent malaria). Pack mosquito repellent, a net and full-sleeved clothes.
• During: sleep under a mosquito net. Use repellent, especially at dusk and dawn. Wear long sleeves. Choose rooms with screens on the windows. Avoid places where water stands still.
• After: if you get fever, chills or headache within a few weeks, see a doctor at once and mention the trip.

(ii) "Malaria is spread by the bite of a mosquito that carries the malaria germ. If the mosquito can't bite you, the germ can't get into your blood. The net and the cream stop the bites, so they keep you from getting sick."

(iii) They may catch malaria. It causes high fever and weakness, and can be very serious or even fatal if not treated in time. They may also carry the infection home, where local mosquitoes could spread it to others.

(i) Consult a doctor, carry repellent and nets; avoid bites during the trip; see a doctor quickly if fever appears afterwards. (ii) Nets and repellents stop the mosquito bites that carry malaria. (iii) They could fall seriously ill and spread the disease further.

(i) "Uncle, I care about you and want you around for a long time. Smoking damages the lungs and heart and can cause cancer. Your real friends will still like you if you don't smoke. Shall we look for help to quit together?" Speak at a calm moment, and share facts rather than blame.

(ii) Say "No, thanks" firmly and confidently. Offer a reason if you want ("I play football; I need my lungs"), change the topic, or move away. Real friends respect your choice.

(iii) Schools can:

• hold awareness sessions with doctors;
• invite former smokers to share their stories;
• run poster and drama activities;
• keep the campus tobacco-free;
• teach students how to say no to peer pressure;
• offer counselling.

The law also bans selling tobacco to minors and near schools.

(i) Talk to him kindly with facts about the harm, and offer support to quit. (ii) Refuse politely but firmly. (iii) Awareness programmes, a tobacco-free campus, and training to resist peer pressure.

• "Do antibiotics work on viruses, like the ones that cause cold, flu or chickenpox?" (No: they work only on bacteria.)
• "What happens if people take antibiotics too often or don't finish the course?" (The bacteria can become resistant, and then the antibiotics stop working.)
• "What about non-communicable diseases like diabetes or asthma? Can an antibiotic cure them?" (No.)
• "Isn't it better to prevent a disease, with clean water, vaccines and hygiene, than to fall sick and need medicines?"

Ask whether antibiotics work against viruses (they don't), whether bacteria can become resistant to them (they can), and whether they cure non-communicable diseases (they don't).

(i) July, August and September, with 65 cases each.

(ii) January, with 10 cases.

(iii) These are the monsoon months. Rain leaves stagnant water in containers, coolers, tyres, pots and potholes, which is where Aedes mosquitoes breed. The warm, humid weather also helps mosquitoes multiply and survive.

(iv) Before the monsoon:

• remove or empty anything that collects water, and change cooler water every week;
• cover water tanks;
• clear drains, and fill potholes;
• spray or fog where advised;
• run awareness drives;
• encourage people to use nets, repellents and full-sleeved clothes;
• prepare hospitals and testing centres.

(i) July, August, September (ii) January (iii) monsoon rain and stagnant water where mosquitoes breed, plus warmth and humidity (iv) remove standing water, cover tanks, clean drains, spray, and run awareness campaigns before the rains.

Against communicable diseases:

• Wash hands with soap before eating and after using the toilet.
• Drink clean, boiled or filtered water.
• Cover coughs and sneezes.
• Get vaccinated on time.
• Don't let water stand still; prevent mosquito bites.
• Stay at home when sick.

Against non-communicable diseases:

• Eat a balanced diet with fruit and vegetables, and less sugar, salt and junk food.
• Exercise or play for at least an hour every day.
• Sleep well, and manage stress.
• Say no to tobacco and alcohol.
• Have regular health check-ups.

Clean hands, safe water, vaccination and no stagnant water against infections; healthy food, daily exercise, enough sleep and no tobacco against lifestyle diseases.

Antibiotics kill or stop bacteria by attacking parts that only bacteria have, such as their cell wall. Viruses do not have these parts, and they live inside our own cells, so antibiotics have no effect on them.

Taking antibiotics unnecessarily also kills useful bacteria in the gut and can cause side effects. It also helps harmful bacteria become resistant, so the medicines may fail when we really need them.

Antibiotics act only on bacteria, not viruses; misuse also causes side effects and antibiotic resistance.

Hepatitis A, poliomyelitis and cholera. These germs leave the body in faeces and enter through contaminated water or food.

Tuberculosis and chickenpox spread through the air, from coughs, sneezes and droplets.

Hepatitis A, poliomyelitis and cholera.

On the first exposure, the immune system meets a germ it has never seen. It takes time to recognise the germ and make the right defence (antibodies), so the response is slow and weak.

It also keeps memory cells that "remember" that germ. When the same germ comes again, these cells recognise it at once and make a fast, strong attack, often before we even feel ill.

This is also how vaccines work: they give the body a safe "first exposure".

The first exposure leaves memory cells; on meeting the same germ again they respond quickly and strongly (the basis of vaccination).