8th Standard, Science, Chapter 3
Health: The Ultimate Treasure
Exercises
Keep the curiosity alive
1. Group the diseases shown in the images as communicable or non-communicable.
Cold and flu Typhoid Diabetes Asthma Chickenpox
Communicable: Cold and Flu, Typhoid, Chickenpox
Non Communicable: Diabetes, Asthama
2. Diseases can be broadly grouped into communicable and non-communicable diseases. From the options given below, identify the non-communicable diseases.
(i) Typhoid
(ii) Asthma
(iii) Diabetes
(iv) Measles
(a) (i) and (ii) (b) (ii) and (iii) (c) (i) and (iv) (d) (ii) and (iv)
Answer: (b) (ii) and (iii)
3. There is a flu outbreak in your School. Several classmates are absent, while some are still coming to school coughing and sneezing.
(i) What immediate actions should the school take to prevent further spread?
Answer: To stop the flu from spreading, the school must immediately isolate and send sick students home, sanitize all shared surfaces, promote handwashing, and cancel large assemblies. Send students who show flu symptoms to the nurse’s office or home to rest. Wipe down desks, door handles, and shared items often. Pause school assemblies and crowded group activities.
(ii) If your classmate, who shares the bench with you, starts showing symptoms of the flu, how can you respond in a considerate way without being rude or hurtful?
Answer: We can respond considerately to a sick classmate by offering help, suggesting they see the nurse, and maintaining basic hygiene without making them feel bad. Kindly propose, “Maybe you should let the teacher know or visit the school nurse so you can rest.”
Offer a tissue or hand sanitizer nicely if they are coughing. Assure them you can share your class notes later.
(iii) How can you protect yourself and others from getting infected in this situation?
Answer: Washing hands frequently, not sharing personal items, covering the mouth and nose.
To protect ourselves and others during a flu outbreak at school, we should practice good hand hygiene, avoid touching our face, and maintain distance from sick individuals.
4. Your family is planning to travel to another city where malaria is prevalent.
(i) What precautions should you take before, during, and after the trip?
Answer: To protect our family from malaria, we must take preventive medicine, avoid mosquito bites, and watch for later signs of illness.
Ask a healthcare provider for advice and get prescription anti-malaria pills (like atovaquone-proguanil, doxycycline, or mefloquine) for each family member. Begin taking the prescribed anti-malaria pills on time before you leave. Buy insect bug spray with DEET, long-sleeve shirts, long pants, and bed nets treated with bug poison
(ii) How can you explain the importance of mosquito nets or repellents to your sibling?
Answer: Explain to your sibling that malaria is caused by the bites of infected mosquitoes. Tell them mosquito nets act like a magical “shield” while sleeping, and sprays are “invisible armor” that keeps bugs away. Show them how to tuck the Insecticide-Treated Mosquito Nets perfectly under the mattress so mosquitoes can’t sneak in.
(iii) What could happen if travellers ignore health advisories in such areas?
Answer: Ignoring health advisories in malaria-prone areas can lead to severe mosquito-borne infections, high fever with chills, and life-threatening medical emergencies requiring hospitalization. Worsening health condition that ruins the trip and causes long-term weakness.
5. Your uncle has started smoking just to fit in with his friends, even though it is well known that smoking can seriously harm health and even cause death.
(i) What would you say to him to make him stop, without being rude?
Answer: To convince our uncle to quit smoking kindly, express our care for his well-being, share our worry about his health, and ask open questions about why he feels the need to fit in, all without sounding judgmental or bossy.
(ii) What would you do if your friend offers you a cigarette at a party?
Answer: If a friend offers a cigarette at a party, I would politely and clearly say “No thanks, I don’t smoke”. I would stand firm in my choice to protect my health, remember the risks of tobacco, and suggest doing something else together instead.
(iii) How can schools help prevent students from indulging in such harmful habits?
Answer: Schools can help prevent students from smoking by teaching health education, building strong peer resistance skills, offering student counseling, and enforcing strict campus rules. Teach clear facts about how smoking damages the lungs, heart, and overall body during science and health classes.
6. Saniya claims to her friend Vinita that “Antibiotics can cure any infection, so we don’t need to worry about diseases.” What question(s) can Vinita ask her to help Saniya understand that her statement is incorrect?
Answer: The question(s) can Vinita ask her to help Saniya understand that her statement is incorrect are as follows.
1 . “Did you know that antibiotics do not work on viral infections like the flu or the common cold?”
2. “Do you know what happens if we take antibiotics for every small illness? Won’t the bacteria become resistant to them?”
3. “Are all diseases caused by bacteria? What about illnesses caused by viruses or fungi?”
4. “If antibiotics cure everything, why do doctors tell us to just rest and drink fluids for a simple viral fever?”
7. The following table contains information about the number of dengue cases reported in a hospital over a period of one year:
Make a bar graph of the number of cases on the Y-axis and the month on the X-axis. Critically analyse your findings and answer the following:
(i) In which three months were the dengue cases highest?
Answer: In July, August and September months were the dengue cases highest.
(ii) In which month(s) were the cases lowest?
Answer: In January month the cases were lowest.
(iii) What natural or environmental factors during the peak months might contribute to the increase in dengue cases?
Answer: The rise in dengue cases during peak monsoon and post-monsoon months is driven by heavy rainfall, warm temperatures, and high humidity. These weather patterns create ideal conditions for mosquito breeding and speed up how fast the virus grows inside the insects.
(iv) Suggest a few preventive steps that the community or government can take before the peak season to reduce the spread of dengue.
Answer: A few preventive steps that the community or government can take before the peak season to reduce the spread of dengue are as follows.
1 . Clean drains and clear blocked water pipes.
2. Spray anti-mosquito medicine in dirty water areas.
3. Check homes and public places for standing water.
4. Keep local hospitals ready with beds and medicine.
5. Empty old tires, pots, and coolers holding clean water.
6. Cover water tanks tightly so mosquitoes cannot enter.
7. Use window nets and insect creams at home.
8. Join local clean-up drives in the neighbourhood.
8. Imagine you are in charge of a school health campaign. What key messages would you use to reduce communicable and non-communicable diseases?
Answer: To reduce communicable and non-communicable diseases in a school campaign, focus on simple habits like regular handwashing, eating balanced meals, staying physically active, avoiding harmful substances, and getting timely vaccinations.
* Use soap and water before eating or after using the restroom.
* Rest at home so you do not spread germs to your classmates.
* Take routine vaccines to build strong protection against dangerous infections.
9. It is recommended that we should not take an antibiotic for a viral infection like a cold, a cough, or flu. Can you provide the possible reason for this recommendation?
Answer: Antibiotics do not work on viral infections like colds, coughs, or the flu because they only kill bacteria. Viruses and bacteria are very different germs. Taking antibiotics when you do not need those wastes medicine and can make future infections harder to treat. You may get an upset stomach, rashes, or lose good bacteria in your body. Antibiotics work on viral illnesses like the flu or common cold, and point out that taking them unnecessarily causes antibiotic resistance.
10. Which disease(s) among the following may spread if drinking water gets contaminated by the excreta from an infected person?
Hepatitis A, Tuberculosis, Poliomyelitis, Cholera, Chickenpox.
Answer: Cholera, Hepatitis A
11. When your body encounters a pathogen for the first time, the immune response is generally low but on exposure to the same pathogen again, the immune response by the body is much more compared to the first exposure. Why is it so?
Answer: When the body encounters a pathogen for the first time, it is slow to recognize it and makes fewer special fighter proteins called antibodies. When the same germ enters again, the body uses special saved cells to recognize it right away. It attacks fast and makes a huge amount of antibodies. The body sees the germ for the first time. It takes time to learn what the germ looks like. Second time the memory cells wake up the immune system right away. The body makes a huge wave of antibodies very fast. The germ is destroyed before it can make you sick.
Discover, Design and Debate:
- Students maintain a health diary for at least a month to track food, hygiene, exercise, sleep, screen time, and emotional state.
- Read about Indian scientists like Suniti Solomon, Asima Chatterjee, Dr. Yellapragada Subbarao, Dr. Mary Poonen Lukose for their contributions in the field of health and diseases.
- The deadly disease smallpox was eradicated by vaccination. Discover how this was done and why it worked. Debate whether everyone should be required to get vaccinated to protect others.
- According to current guidelines, learn the correct sequence of steps for performing cardiopulmonary resuscitation (CPR) on an adult in case of sudden stoppage of breathing. School may invite a doctor or a professional to demonstrate a mock drill.
- Invite a doctor to the school. Students may be encouraged to interact with the doctor on the issues of malnutrition, under-nutrition, and over-nutrition.
- If you are given an opportunity to create a health card, what all would you like to include in it. Create your own health card and have discussion about it.
- Have a debate on ‘Are there ill-effects of fast food on companion animals?
