NCERT Solutions for Class 8 Science Curiosity Chapter 3 Health: The Ultimate Treasure

NCERT Solutions for Class 8 Science Curiosity Chapter 3 Health: The Ultimate Treasure स्वास्थय  एक अमूल्य निधि

Page 28 NCERT Probe and Ponder Questions

Question 1.
How does your body respond to an infection such as the common cold?
आपका शरीर सामान्य सर्दी-जुकाम जैसे संक्रमण के प्रति कैसे अनुक्रिया करता है?
Answer:
When germs causing the common cold enter the body, the immune system becomes active. White blood cells identify and destroy the germs. The body may develop symptoms like sneezing, coughing, fever, and a runny nose to remove the infection. Antibodies are also produced, helping the body fight the infection and recover faster.
जब सामान्य सर्दी-जुकाम के रोगाणु शरीर में प्रवेश करते हैं, तो प्रतिरक्षा तंत्र सक्रिय हो जाता है। श्वेत रक्त कणिकाएँ रोगाणुओं की पहचान कर उन्हें नष्ट करती हैं। शरीर छींक, खाँसी, बुखार और नाक बहने जैसे लक्षण उत्पन्न करता है ताकि संक्रमण को बाहर निकाला जा सके। साथ ही, शरीर प्रतिरक्षी बनाता है, जो संक्रमण से लड़कर शरीर को स्वस्थ होने में सहायता करते हैं।

Question 2.
We rarely see cases of smallpox or polio these days, but diseases like diabetes and heart problems are more common. Why?
वर्तमान मेें हम चेचक या पोलियो जैसे रोग कम ही देखते हैैं परंतु मधुमुेह और हृदय संबंधी रोग अधिक सामान्य हो गए हैैं। ऐसा क्यों है?
Answer:
Smallpox has been eradicated and polio has greatly reduced because of vaccination, improved sanitation, and better healthcare. However, diabetes and heart diseases are increasing due to unhealthy lifestyles, lack of physical activity, stress, unhealthy eating habits, obesity, and ageing. These are non-communicable diseases and cannot be prevented by vaccines.
चेचक का पूरी तरह उन्मूलन हो चुका है और पोलियो के मामले टीकाकरण, बेहतर स्वच्छता तथा स्वास्थ्य सेवाओं के कारण बहुत कम हो गए हैं। दूसरी ओर, मधुमेह और हृदय रोग अस्वास्थ्यकर जीवनशैली, शारीरिक गतिविधि की कमी, तनाव, असंतुलित भोजन, मोटापा तथा बढ़ती आयु के कारण बढ़ रहे हैं। ये गैर-संचारी रोग हैं और इनसे बचाव टीकों द्वारा नहीं किया जा सकता।

Question 3.
Could climate change lead to new types of diseases?
क्या जलवायु परिवर्तन नए प्रकार के रोगों की उत्पत्ति का कारण बन सकता है?
Answer:
Yes. Climate change can spread disease-carrying insects, increase infections, and create conditions for new diseases to emerge and spread.
हाँ। जलवायु परिवर्तन रोग फैलाने वाले कीटों को बढ़ाता है, संक्रमण फैलाता है तथा नए रोगों के उत्पन्न होने की परिस्थितियाँ बनाता है।

Question 4.
How do emotions like stress or worry affect us and make us sick?
तनाव या चिंता जैसे संवेग हमेें किस प्रकार प्रभावित करते हैैं एवं रोगी बनाते हैैं?
Answer:
Stress and worry can weaken the immune system, disturb sleep, reduce appetite, and affect digestion. Long-term stress may increase the risk of high blood pressure, heart disease, anxiety, and other health problems. Managing emotions helps maintain good physical and mental health.
तनाव और चिंता हमारी प्रतिरक्षा क्षमता को कमज़ोर करते हैं, नींद, भूख और पाचन को प्रभावित करते हैं। लंबे समय तक तनाव रहने से उच्च रक्तचाप, हृदय रोग, चिंता तथा अन्य स्वास्थ्य समस्याओं का खतरा बढ़ जाता है। मानसिक संतुलन बनाए रखना अच्छे स्वास्थ्य के लिए आवश्यक है।

Question 5.
Why do some groups of people get affected more than others during disease outbreaks?
रोग के प्रकोप के समय कुछ वगों के लोग दूसरे वगों की तुलना मेें अधिक प्रभावित क्यों होते हैैं?
Answer:
Some people are more affected because they have weaker immunity, poor nutrition, old age, or existing illnesses. Young children, elderly people, and those living in overcrowded or unhygienic conditions are at greater risk. Good nutrition, hygiene, and vaccination help protect them.
कुछ लोग कमज़ोर प्रतिरक्षा, कुपोषण, अधिक आयु या पहले से मौजूद बीमारियों के कारण अधिक प्रभावित होते हैं। छोटे बच्चे, बुज़ुर्ग तथा भीड़भाड़ और अस्वच्छ स्थानों में रहने वाले लोगों को संक्रमण का खतरा अधिक रहता है। संतुलित आहार, स्वच्छता और टीकाकरण उनकी सुरक्षा में सहायक हैं।

Pages 42-45 Keep the Curiosity Alive

Question 1.
Group the diseases shown in the images as communicable or non-communicable.

Answer:
Communicable Diseases

• Cold and Flu
• Typhoid Chickenpox

Non-communicable Diseases

• Diabetes
• Asthma

Question 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)

Question 3.
There is a flu outbreak in your school. Several classmates are absent, while some are still coming to school coughing and sneezing.

1. What immediate actions should the school take to prevent further spread?
2. 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?
3. How can you protect yourself and others from getting infected in this situation?

Answer:

1. The school should close temporarily, sanitise classrooms, and encourage sick students to stay home to prevent further spread.
2. You can politely suggest that your classmate see a doctor and take a rest at home, and offer to share notes with them.
3. To protect yourself and others, wash your hands frequently, avoid close contact, and wear a mask.

Question 4.
Your family is planning to travel to another city where malaria is prevalent.

1. What precautions should you take before, during, and after the trip?
2. How can you explain the importance of mosquito nets or repellents to your sibling?
3. What could happen if travellers ignore health advisories in such areas?

Answer:

1. To protect our family from malaria during travel, focus on preventing mosquito bites and taking prescribed preventative medication.
   • Before travel, consult a doctor, get necessary vaccinations, and pack mosquito repellent and protective clothing.
   • During the trip, continue using repellent, wear long sleeves and pants, and sleep under mosquito nets.
   • After returning, monitor for any symptoms like fever, and seek immediate medical attention if they occur.
2. Explain to your sibling that mosquitoes spread malaria and that nets or repellents protect by blocking bites.
3. If travellers ignore health advisories in such areas, they risk malaria infection, severe illness, or even death.

Question 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.

1. What would you say to him to make him stop, without being rude?
2. What would you do if your friend offered you a cigarette at a party?
3. How can schools help prevent students from indulging in such harmful habits?

Answer:

1. Dear Uncle, I care about your health and well-being, and I want to talk to you about smoking. It’s well-known that smoking can lead to serious health issues, including heart disease and lung cancer. Quitting smoking can greatly improve your health and quality of life.
2. Politely decline the cigarette at the party and explain the health risks to your friend.
3. Schools can help prevent students from indulging in such habits by educating them about the health risks and organizing awareness programs regularly.

Question 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:
Why Saniya’s Statement is Wrong:

• Antibiotics only work against bacterial infections, not viral ones like the flu or common cold.
• Overuse or misuse of antibiotics can lead to antibiotic resistance, making them less effective in the future.
• Some diseases are caused by fungi, protozoa, or viruses, which require different treatments.

Vanita can ask Saniya, Did you know that antibiotics don’t work on viruses like the flu or measles? They’re only useful for bacterial infections. Also, if we take antibiotics when we don’t need them, they might stop working when we really do. That’s why doctors are careful about prescribing them.”

Question 7.
The following table contains information about the number of dengue cases reported in a hospital over 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:

1. In which three months were the dengue cases highest?
2. In which month(s) were the cases lowest?
3. What natural or environmental factors during the peak months might contribute to the increase in dengue cases?
4. Suggest a few preventive steps that the community or government can take before the peak season to reduce the spread of dengue.

Answer:

1. The dengue cases were highest in July, August, and September.
2. The cases were lowest in January.
3. Natural or environmental factors during the peak months, such as the rainy season and standing water for mosquito breeding, might contribute to the increase in dengue cases.
4. The community or government can take preventive steps like removing stagnant water, using mosquito nets, and spraying insecticides during this period regularly to reduce the spread of dengue.

Question 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:
Key messages for a school health campaign to reduce communicable and non-communicable diseases include washing hands regularly, eating a healthy diet, exercising daily, getting vaccinated, and avoiding smoking.

Question 9.
It is recommended that we not take an antibiotic for a viral infection like a cold, a cough, or the flu. Can you provide the possible reason for this recommendation?
Answer:
The recommendation to avoid antibiotics for a viral infection like a cold, cough, or flu is because antibiotics do not work on viruses, which cause these illnesses.

Question 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:
The diseases that may spread if drinking water gets contaminated by the excreta from an infected person are Hepatitis A, Poliomyelitis, and Cholera.

Question 11.
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?
Answer:
When our body faces a pathogen (like a virus or bacteria) for the first time, our immune system needs time to:

• Identify the invader
• Create specific antibodies
• Build memory cells that remember the pathogen

This first reaction is called the primary immune response, and it’s usually slow and weak.
When the same pathogen enters our body again:

• Our memory B cells quickly produce the correct antibodies
• Our memory T cells help destroy infected cells faster

This is called the secondary immune response, and it’s faster, stronger, and more effective.