Health: The Ultimate TreasureClass 8 Science NCERT Solutions
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Q1Keep the curiosity alive
Group the diseases shown in the images as communicable or non-communicable.
Solution
The diseases can be grouped as follows:
- Communicable Diseases: Cold and flu, Typhoid, Chickenpox
- Non-communicable Diseases: Diabetes, Asthma
Q2Keep the curiosity alive
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)
Solution
The correct answer is (b) (ii) and (iii).
Q3Keep the curiosity alive
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?
(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?
(iii)
How can you protect yourself and others from getting infected in this situation?
Solution
(i)
The school should take the following immediate actions to prevent further spread of the flu:
- Inform parents about the outbreak and advise them to keep sick children at home.
- Provide hand sanitizers in classrooms and common areas.
- Ensure regular cleaning and disinfection of frequently touched surfaces.
- Promote awareness about proper handwashing and respiratory hygiene.
- Consider temporarily closing the school if the outbreak is severe.
(ii)
If a classmate starts showing symptoms of the flu, I can respond in a considerate way by:
- Offering a tissue and suggesting they inform the teacher or school nurse.
- Maintaining a safe distance to avoid direct contact.
- Avoiding sharing personal items like pens or water bottles.
- Expressing concern and offering support while avoiding judgmental comments.
(iii)
To protect myself and others from getting infected in this situation, I can:
- Wash my hands frequently with soap and water.
- Avoid touching my face, especially my eyes, nose, and mouth.
- Maintain a safe distance from individuals who are coughing or sneezing.
- Ensure proper ventilation in the classroom.
- Consider wearing a mask if the outbreak is severe.
Q4Keep the curiosity alive
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?
(ii)
How can you explain the importance of mosquito nets or repellents to your sibling?
(iii)
What could happen if travellers ignore health advisories in such areas?
Solution
(i)
Precautions to take before, during, and after the trip to a malaria-prone area:
- Before: Consult a doctor about malaria preventive medication and vaccinations.
- During: Use mosquito nets and repellents, wear long-sleeved clothes, and avoid areas with still water where mosquitoes breed.
- After: Watch for malaria symptoms (high fever, chills, sweating) and seek immediate medical attention if any symptoms appear.
(ii)
Explaining the importance of mosquito nets or repellents to a sibling:
- Mosquito nets and repellents protect us from mosquito bites, which can spread diseases like malaria.
- Malaria can make us very sick, causing high fever, chills, and other serious problems.
- Using nets and repellents is a simple way to prevent mosquito bites and stay healthy.
(iii)
Consequences of ignoring health advisories in malaria-prone areas:
- Increased risk of contracting malaria.
- Potential development of severe symptoms requiring hospitalization.
- Possible long-term health complications or even death in severe cases.
Q5Keep the curiosity alive
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?
(ii)
What would you do if your friend offers you a cigarette at a party?
(iii)
How can schools help prevent students from indulging in such harmful habits?
Solution
(i)
To persuade my uncle to stop smoking without being rude, I would say:
- "Uncle, I am concerned about your health. I know you are doing this to fit in, but smoking can cause serious health problems like cancer and heart disease."
- "Is there anything else you could do to connect with your friends that would be healthier for you? Your health is really important to us."
(ii)
If a friend offers me a cigarette at a party, I would:
- Politely decline by saying, "No, thank you. I do not smoke."
- If they persist, I would firmly say, "I am not interested. I care about my health."
- I would avoid the situation if possible.
(iii)
Schools can help prevent students from indulging in harmful habits by:
- Educating students about the dangers of smoking, alcohol, and drugs through health classes and workshops.
- Providing counseling and support services for students struggling with peer pressure or addiction.
- Implementing strict policies against smoking and drug use on school premises.
- Promoting healthy lifestyles through sports, extracurricular activities, and positive role models.
Q6Keep the curiosity alive
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?
Solution
Vinita can ask Saniya the following questions to help her understand that her statement is incorrect:
- "Do antibiotics work on all types of infections, like those caused by viruses, or just specific ones?"
- "Have you heard of antibiotic resistance? What happens when bacteria become resistant to antibiotics?"
- "What about non-communicable diseases like diabetes or asthma? Can antibiotics cure those?"
Q7Keep the curiosity alive
The following table contains information about the number of dengue cases reported in a hospital over a period of one year:
S. No. 1 2 3 4 5 6 Month January February March April May June No. of dengue cases 10 12 15 18 22 40
S. No. 7 8 9 10 11 12 Month July August September October November December No. of dengue cases 65 65 65 30 30 20
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?
(ii)
In which month(s) were the cases lowest?
(iii)
What natural or environmental factors during the peak months might contribute to the increase in dengue cases?
(iv)
Suggest a few preventive steps that the community or government can take before the peak season to reduce the spread of dengue.
Solution
(i)
The dengue cases were highest in July, August, and September.
(ii)
The dengue cases were lowest in January.
(iii)
Natural or environmental factors contributing to the increase in dengue cases during the peak months (July, August, September) include:
- Monsoon Season: Increased rainfall leads to stagnant water accumulation, creating breeding grounds for mosquitoes.
- Humidity: High humidity levels favor mosquito survival and breeding.
- Temperature: Warm temperatures accelerate the mosquito life cycle and increase their activity.
(iv)
Preventive steps that the community or government can take before the peak season to reduce the spread of dengue:
- Public Awareness Campaigns: Educate the community about dengue prevention measures, such as eliminating stagnant water and using mosquito repellents.
- Vector Control: Conduct regular fogging and spraying to kill mosquitoes and larvae.
- Source Reduction: Remove or cover potential breeding sites like discarded tires, containers, and flower pots.
- Community Clean-up Drives: Organize community clean-up drives to eliminate breeding sites and promote environmental sanitation.
- Surveillance and Monitoring: Implement surveillance systems to monitor mosquito populations and dengue cases, allowing for early detection and response.
Q8Keep the curiosity alive
Imagine you are in charge of a school health campaign. What key messages would you use to reduce communicable and non-communicable diseases?
Solution
Key messages for a school health campaign to reduce communicable and non-communicable diseases:
- Communicable Diseases:
- "Wash your hands frequently to prevent the spread of germs."
- "Cover your mouth and nose when you cough or sneeze."
- "Get vaccinated to protect yourself and others from infectious diseases."
- "Keep your surroundings clean to prevent mosquito breeding."
- Non-Communicable Diseases:
- "Eat a balanced diet with plenty of fruits and vegetables."
- "Stay physically active by playing outdoors or exercising regularly."
- "Limit screen time and get enough sleep."
- "Say no to tobacco, alcohol, and drugs."
- "Manage stress through relaxation techniques like yoga or meditation."
Q9Keep the curiosity alive
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?
Solution
The reason it is not recommended to take antibiotics for viral infections like a cold, cough, or flu is that antibiotics are effective only against bacterial infections. Viruses and bacteria are different types of pathogens, and antibiotics target specific structures and processes in bacteria that are not present in viruses. Taking antibiotics for viral infections will not cure the infection and can contribute to the development of antibiotic resistance, making bacterial infections harder to treat in the future.
Q10Keep the curiosity alive
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.
Solution
The diseases that may spread if drinking water gets contaminated by the excreta from an infected person are Hepatitis A, Poliomyelitis, and Cholera.
Q11Keep the curiosity alive
When our 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?
Solution
When the body encounters a pathogen for the first time, the immune response is generally low because the immune system needs time to recognize the pathogen, produce antibodies, and activate immune cells to fight the infection. This initial response is called the primary immune response.
Upon subsequent exposure to the same pathogen, the immune response is much more rapid and stronger. This is because the immune system has developed immunological memory. During the primary response, some immune cells, called memory cells, are created. These memory cells 'remember' the pathogen. When the same pathogen enters the body again, these memory cells quickly recognize it and trigger a faster and more effective secondary immune response, leading to a more robust defense against the infection.
Q1Prepare some questions based on your learnings so far ...
Solution
This section prompts the student to create their own questions based on the chapter. Therefore, a specific answer cannot be provided.
Q1Reflect on the questions framed by your friends and try to answer ...
Solution
This section prompts the student to reflect and answer questions created by their peers. Therefore, a specific answer cannot be provided.