Chapter 13 – Why Do We Fall Ill – MCQs
Chapter 13 – Why Do We Fall Ill – MCQs (Part 1: Q1–Q25)
Q1. Which of the following is NOT a factor that determines health?
a) Balanced diet
b) Good housing
c) Chronic illness
d) Playing video games
Answer: d) Playing video games
👉 Explanation: Balanced diet, good housing, and absence of chronic illness affect health. Playing video games does not directly determine overall health.
Q2. Which of the following is the meaning of “disease”?
a) State of well-being
b) Discomfort and disturbed functioning of body
c) Absence of microbes
d) Immunity development
Answer: b) Discomfort and disturbed functioning of body
👉 Explanation: Disease refers to an abnormal condition that impairs normal body functions, leading to discomfort and lack of ease.
Q3. Which one is an example of an acute disease?
a) Diabetes
b) Tuberculosis
c) Common cold
d) Arthritis
Answer: c) Common cold
👉 Explanation: Acute diseases last for a short time (e.g., cold, flu), whereas diabetes, TB, and arthritis are long-term chronic diseases.
Q4. Which is a chronic disease?
a) Malaria
b) Typhoid
c) Tuberculosis
d) Influenza
Answer: c) Tuberculosis
👉 Explanation: Chronic diseases last for months or years (e.g., TB, diabetes). Malaria, typhoid, influenza are acute diseases.
Q5. Which of the following is a non-infectious disease?
a) Malaria
b) Diabetes
c) Tuberculosis
d) Typhoid
Answer: b) Diabetes
👉 Explanation: Non-infectious diseases are not caused by pathogens and cannot spread. Diabetes is due to insulin deficiency.
Q6. Infectious diseases are caused by:
a) Nutritional deficiency
b) Pathogens
c) Genetic factors
d) Lifestyle
Answer: b) Pathogens
👉 Explanation: Infectious diseases are caused by microorganisms like bacteria, viruses, fungi, protozoa, and worms.
Q7. Which of the following is NOT an infectious agent?
a) Virus
b) Bacteria
c) Fungus
d) Vitamin
Answer: d) Vitamin
👉 Explanation: Vitamins are nutrients, not disease-causing microbes. Viruses, bacteria, and fungi are pathogens.
Q8. Which organ is affected in jaundice?
a) Kidney
b) Liver
c) Lungs
d) Heart
Answer: b) Liver
👉 Explanation: Jaundice is caused by liver malfunction, leading to accumulation of bile pigments in the body.
Q9. Which disease is spread through contaminated water?
a) Cholera
b) Tuberculosis
c) AIDS
d) Chickenpox
Answer: a) Cholera
👉 Explanation: Cholera spreads via contaminated water or food. TB spreads by air, AIDS by sexual contact/blood, chickenpox by air.
Q10. Which pathogen causes malaria?
a) Virus
b) Fungus
c) Protozoa
d) Bacteria
Answer: c) Protozoa
👉 Explanation: Malaria is caused by Plasmodium (protozoa) transmitted by female Anopheles mosquitoes.
Q11. Which organism causes tuberculosis?
a) Plasmodium
b) Mycobacterium
c) Virus
d) Fungi
Answer: b) Mycobacterium
👉 Explanation: Tuberculosis is caused by Mycobacterium tuberculosis, a bacterium.
Q12. Which of the following is not transmitted by mosquitoes?
a) Malaria
b) Dengue
c) Typhoid
d) Chikungunya
Answer: c) Typhoid
👉 Explanation: Typhoid spreads via contaminated food/water, not mosquito bites. Mosquitoes spread malaria, dengue, chikungunya.
Q13. Which of the following is a viral disease?
a) Typhoid
b) AIDS
c) Tuberculosis
d) Cholera
Answer: b) AIDS
👉 Explanation: AIDS is caused by HIV (virus). Typhoid (bacteria), TB (bacteria), and cholera (bacteria).
Q14. Which is the causative agent of AIDS?
a) HIV
b) HBV
c) HCV
d) H1N1
Answer: a) HIV
👉 Explanation: AIDS is caused by Human Immunodeficiency Virus (HIV).
Q15. Which disease is caused by deficiency of iodine?
a) Anaemia
b) Goitre
c) Rickets
d) Scurvy
Answer: b) Goitre
👉 Explanation: Goitre is caused due to lack of iodine, leading to swelling of thyroid gland.
Q16. Which vitamin deficiency causes rickets?
a) Vitamin A
b) Vitamin B
c) Vitamin C
d) Vitamin D
Answer: d) Vitamin D
👉 Explanation: Vitamin D deficiency leads to weak bones, causing rickets.
Q17. Which disease is called a water-borne disease?
a) Tuberculosis
b) Cholera
c) AIDS
d) Malaria
Answer: b) Cholera
👉 Explanation: Cholera spreads via contaminated water.
Q18. Which is the mode of transmission for tuberculosis?
a) Air
b) Water
c) Mosquito
d) Sexual contact
Answer: a) Air
👉 Explanation: Tuberculosis spreads by inhaling droplets released from infected persons.
Q19. Which disease is not caused by microorganisms?
a) Diabetes
b) Polio
c) Typhoid
d) Malaria
Answer: a) Diabetes
👉 Explanation: Diabetes is a lifestyle/metabolic disease, not infectious. Polio (virus), Typhoid (bacteria), Malaria (protozoa).
Q20. Which of the following can weaken the immune system?
a) HIV infection
b) Balanced diet
c) Vaccination
d) Good sleep
Answer: a) HIV infection
👉 Explanation: HIV destroys WBCs, weakening immunity.
Q21. Which of these is an example of prevention?
a) Antibiotics
b) Vaccination
c) Surgery
d) Painkillers
Answer: b) Vaccination
👉 Explanation: Vaccination prevents diseases by building immunity.
Q22. Which disease is NOT preventable by vaccination?
a) Polio
b) Measles
c) Diabetes
d) Hepatitis B
Answer: c) Diabetes
👉 Explanation: Vaccination prevents infectious diseases, not metabolic disorders like diabetes.
Q23. What is the full form of AIDS?
a) Acquired Immune Deficiency Syndrome
b) Acute Immune Disease Syndrome
c) Acquired Infection Deficiency Syndrome
d) Auto Immune Disease Syndrome
Answer: a) Acquired Immune Deficiency Syndrome
👉 Explanation: AIDS stands for Acquired Immune Deficiency Syndrome.
Q24. Which of the following is the most effective way to control malaria?
a) Antibiotics
b) Spraying insecticides
c) Taking painkillers
d) Boiling drinking water
Answer: b) Spraying insecticides
👉 Explanation: Malaria spreads via mosquitoes; controlling mosquitoes is key to prevention.
Q25. Which disease is spread by houseflies?
a) Cholera
b) Malaria
c) Dengue
d) AIDS
Answer: a) Cholera
👉 Explanation: Houseflies carry germs from waste to food, spreading cholera.
Why Do We Fall Ill – MCQs (Part 2: Q26–Q50)
Q26. Which of the following is a communicable disease?
a) Cancer
b) Typhoid
c) Diabetes
d) Hypertension
Answer: b) Typhoid
👉 Explanation: Typhoid spreads by contaminated food/water. Cancer, diabetes, hypertension are non-communicable.
Q27. Which nutrient deficiency causes anaemia?
a) Iodine
b) Calcium
c) Iron
d) Vitamin C
Answer: c) Iron
👉 Explanation: Anaemia occurs due to iron deficiency, leading to reduced haemoglobin.
Q28. Rabies virus is generally transmitted by:
a) Insects
b) Mosquito bites
c) Dog bite
d) Contaminated water
Answer: c) Dog bite
👉 Explanation: Rabies spreads through saliva of rabid animals, commonly by dog bite.
Q29. Which part of the body is mainly affected by pneumonia?
a) Liver
b) Kidneys
c) Lungs
d) Brain
Answer: c) Lungs
👉 Explanation: Pneumonia causes inflammation in alveoli of lungs, reducing oxygen exchange.
Q30. Which of the following is a fungal disease?
a) Ringworm
b) Polio
c) Tuberculosis
d) Cholera
Answer: a) Ringworm
👉 Explanation: Ringworm is caused by fungi. Polio (virus), TB (bacteria), Cholera (bacteria).
Q31. Which is a non-communicable disease?
a) Hypertension
b) Measles
c) Chickenpox
d) Tuberculosis
Answer: a) Hypertension
👉 Explanation: Hypertension is not infectious; it results from lifestyle and genetic factors.
Q32. The carrier of malaria parasite is:
a) Male Anopheles mosquito
b) Female Anopheles mosquito
c) Housefly
d) Sandfly
Answer: b) Female Anopheles mosquito
👉 Explanation: Only female Anopheles mosquito transmits malaria (Plasmodium parasite).
Q33. Which organ is damaged in hepatitis?
a) Lungs
b) Kidney
c) Liver
d) Heart
Answer: c) Liver
👉 Explanation: Hepatitis is inflammation of liver caused by viral infection.
Q34. Which is NOT a principle of treatment of infectious diseases?
a) Kill the infectious agent
b) Reduce symptoms
c) Boost immunity
d) Take junk food
Answer: d) Take junk food
👉 Explanation: Treatment involves killing microbes, controlling symptoms, and boosting immunity, not eating junk food.
Q35. Which is a principle of prevention of diseases?
a) Vaccination
b) Surgery
c) Painkillers
d) Antibiotics
Answer: a) Vaccination
👉 Explanation: Prevention aims to stop disease occurrence (vaccination, hygiene), unlike surgery or treatment.
Q36. Which one is a bacterial disease?
a) Polio
b) Measles
c) Typhoid
d) Chickenpox
Answer: c) Typhoid
👉 Explanation: Typhoid is caused by Salmonella typhi bacteria. Polio and measles (virus), chickenpox (virus).
Q37. Which disease spreads mainly by unsafe sexual contact?
a) Malaria
b) AIDS
c) Cholera
d) Tuberculosis
Answer: b) AIDS
👉 Explanation: HIV spreads through sexual contact, blood transfusion, and sharing needles.
Q38. Which disease is spread through contaminated food?
a) Tuberculosis
b) Typhoid
c) Dengue
d) Malaria
Answer: b) Typhoid
👉 Explanation: Typhoid spreads via contaminated food/water. TB (airborne), dengue/malaria (mosquitoes).
Q39. Which is a protozoan disease?
a) Malaria
b) Cholera
c) Pneumonia
d) Influenza
Answer: a) Malaria
👉 Explanation: Malaria is caused by protozoan Plasmodium. Cholera (bacteria), pneumonia (bacteria/virus), influenza (virus).
Q40. Which of the following diseases is NOT transmitted by air?
a) Tuberculosis
b) Influenza
c) Typhoid
d) Common cold
Answer: c) Typhoid
👉 Explanation: Typhoid spreads via contaminated food/water. TB, cold, influenza are airborne.
Q41. Which of the following is an epidemic disease?
a) Malaria
b) Influenza
c) Cancer
d) Diabetes
Answer: b) Influenza
👉 Explanation: Epidemics are sudden outbreaks in a population. Influenza can cause widespread epidemics.
Q42. Which of these is a deficiency disease?
a) Goitre
b) Cholera
c) Malaria
d) Polio
Answer: a) Goitre
👉 Explanation: Goitre is caused by iodine deficiency. Others are infectious diseases.
Q43. Which of the following helps in early recovery from disease?
a) Good nutrition
b) Unhygienic lifestyle
c) Polluted environment
d) Starvation
Answer: a) Good nutrition
👉 Explanation: Proper nutrition provides energy and boosts immunity for recovery.
Q44. Which one is NOT a method of disease transmission?
a) Air
b) Water
c) Food
d) Meditation
Answer: d) Meditation
👉 Explanation: Diseases spread through air, water, food, vectors – not through meditation.
Q45. Which type of disease lasts for a long period of time?
a) Acute
b) Chronic
c) Infectious
d) Non-infectious
Answer: b) Chronic
👉 Explanation: Chronic diseases last for months or years (e.g., TB, diabetes).
Q46. Which disease is caused by a worm?
a) Ascariasis
b) Typhoid
c) Tuberculosis
d) Polio
Answer: a) Ascariasis
👉 Explanation: Ascariasis is caused by roundworms (Ascaris lumbricoides). Others are caused by bacteria/viruses.
Q47. Which of the following statements is correct?
a) All diseases are infectious
b) All diseases are genetic
c) Some diseases are infectious, some are not
d) No disease is preventable
Answer: c) Some diseases are infectious, some are not
👉 Explanation: Diseases can be infectious (TB, malaria) or non-infectious (diabetes, cancer).
Q48. Which disease spreads through vectors?
a) Malaria
b) Cholera
c) Tuberculosis
d) Polio
Answer: a) Malaria
👉 Explanation: Malaria spreads through mosquito vector. Cholera (water), TB (air), Polio (virus-contaminated food/water).
Q49. Which disease is caused by lack of Vitamin C?
a) Anaemia
b) Rickets
c) Scurvy
d) Goitre
Answer: c) Scurvy
👉 Explanation: Vitamin C deficiency causes scurvy, leading to bleeding gums and weak immunity.
Q50. Which disease is called a lifestyle disease?
a) Diabetes
b) Cholera
c) Typhoid
d) Malaria
Answer: a) Diabetes
👉 Explanation: Lifestyle diseases (diabetes, hypertension) occur due to poor diet, lack of exercise, stress—not pathogens.
Why Do We Fall Ill – MCQs (Part 3: Q51–Q75)
Q51. Which of the following is NOT an example of an acute disease?
a) Cold
b) Influenza
c) Chickenpox
d) Diabetes
Answer: d) Diabetes
👉 Explanation: Diabetes is a chronic, long-term disease. Cold, influenza, and chickenpox are acute, short-term illnesses.
Q52. Which one of the following is an example of chronic disease?
a) Malaria
b) Pneumonia
c) Hypertension
d) Typhoid
Answer: c) Hypertension
👉 Explanation: Hypertension lasts for years, hence chronic. Malaria, pneumonia, and typhoid are acute diseases.
Q53. Which organ is affected by polio virus?
a) Lungs
b) Nerves
c) Liver
d) Kidneys
Answer: b) Nerves
👉 Explanation: Polio virus affects the nervous system, sometimes causing paralysis.
Q54. Which microorganism causes influenza?
a) Bacteria
b) Virus
c) Fungus
d) Protozoa
Answer: b) Virus
👉 Explanation: Influenza is caused by influenza virus, not by bacteria, fungi, or protozoa.
Q55. Which of the following diseases spreads through unsafe blood transfusion?
a) Cholera
b) AIDS
c) Malaria
d) Tuberculosis
Answer: b) AIDS
👉 Explanation: HIV can spread by unsafe blood transfusion, sharing needles, and sexual contact.
Q56. Which vitamin is important for healthy eyesight?
a) Vitamin A
b) Vitamin B
c) Vitamin C
d) Vitamin D
Answer: a) Vitamin A
👉 Explanation: Vitamin A deficiency causes night blindness and poor vision.
Q57. Which disease is NOT caused by bacteria?
a) Tuberculosis
b) Typhoid
c) Cholera
d) Chickenpox
Answer: d) Chickenpox
👉 Explanation: Chickenpox is caused by virus, while TB, typhoid, and cholera are bacterial.
Q58. Which of these is a preventive measure against cholera?
a) Vaccination
b) Use of antibiotics
c) Use of painkillers
d) Regular exercise
Answer: a) Vaccination
👉 Explanation: Prevention of cholera includes vaccination, clean water, and sanitation.
Q59. The organism that causes kala-azar is:
a) Plasmodium
b) Leishmania
c) Virus
d) Bacteria
Answer: b) Leishmania
👉 Explanation: Kala-azar is caused by protozoan Leishmania transmitted by sandfly.
Q60. Which one is a water-borne disease?
a) Typhoid
b) Malaria
c) Dengue
d) Tuberculosis
Answer: a) Typhoid
👉 Explanation: Typhoid spreads through contaminated water. Malaria/dengue (mosquitoes), TB (airborne).
Q61. Which of the following is an air-borne disease?
a) Typhoid
b) Malaria
c) Tuberculosis
d) Ascariasis
Answer: c) Tuberculosis
👉 Explanation: TB spreads through droplets in the air from infected persons.
Q62. The vaccine for tuberculosis is called:
a) DPT
b) BCG
c) OPV
d) Hepatitis B vaccine
Answer: b) BCG
👉 Explanation: BCG (Bacillus Calmette–Guérin) vaccine is used to prevent TB.
Q63. Which of the following is a vector-borne disease?
a) Cholera
b) Malaria
c) AIDS
d) Typhoid
Answer: b) Malaria
👉 Explanation: Malaria spreads through mosquito vector, unlike cholera (water), AIDS (sexual contact), typhoid (food/water).
Q64. Which is NOT a symptom of malaria?
a) High fever with chills
b) Sweating
c) Joint pain
d) Anaemia
Answer: c) Joint pain
👉 Explanation: Malaria shows symptoms like fever, chills, sweating, and anaemia, but not joint pain (typical in chikungunya).
Q65. Which is a deficiency disease caused by lack of Vitamin D?
a) Scurvy
b) Rickets
c) Goitre
d) Anaemia
Answer: b) Rickets
👉 Explanation: Vitamin D deficiency causes rickets (weak, deformed bones).
Q66. Which of the following diseases is NOT caused by a virus?
a) Measles
b) AIDS
c) Tuberculosis
d) Polio
Answer: c) Tuberculosis
👉 Explanation: TB is caused by bacteria. Measles, AIDS, and polio are viral.
Q67. Which pathogen causes cholera?
a) Virus
b) Fungus
c) Vibrio cholerae
d) Plasmodium
Answer: c) Vibrio cholerae
👉 Explanation: Cholera is caused by Vibrio cholerae bacteria.
Q68. Which disease is caused by uncontrolled cell division?
a) Cancer
b) Diabetes
c) Polio
d) Typhoid
Answer: a) Cancer
👉 Explanation: Cancer is due to uncontrolled growth of abnormal body cells.
Q69. Which is a symptom of jaundice?
a) Yellowing of skin and eyes
b) Weak bones
c) Bleeding gums
d) Swelling of neck
Answer: a) Yellowing of skin and eyes
👉 Explanation: Jaundice occurs due to liver malfunction, causing bile pigment deposition.
Q70. Which is the causative organism of ringworm?
a) Bacteria
b) Fungus
c) Virus
d) Protozoa
Answer: b) Fungus
👉 Explanation: Ringworm is a fungal infection, not bacterial or viral.
Q71. Which one of these is an insect-borne disease?
a) Typhoid
b) Tuberculosis
c) Dengue
d) Scurvy
Answer: c) Dengue
👉 Explanation: Dengue is caused by a virus transmitted by Aedes aegypti mosquito.
Q72. Which disease is caused by deficiency of protein in children?
a) Kwashiorkor
b) Marasmus
c) Anaemia
d) Both (a) and (b)
Answer: d) Both (a) and (b)
👉 Explanation: Kwashiorkor and marasmus are protein-energy malnutrition diseases in children.
Q73. Which disease spreads by contaminated milk?
a) Tuberculosis
b) Typhoid
c) Polio
d) Rabies
Answer: a) Tuberculosis
👉 Explanation: TB bacteria can spread through contaminated unpasteurized milk.
Q74. Which of the following is a symptom of scurvy?
a) Night blindness
b) Bone weakness
c) Bleeding gums
d) Swollen thyroid
Answer: c) Bleeding gums
👉 Explanation: Scurvy (Vitamin C deficiency) causes bleeding gums and delayed wound healing.
Q75. Which disease is caused by the bite of a rabid dog?
a) Tetanus
b) Rabies
c) Malaria
d) Dengue
Answer: b) Rabies
👉 Explanation: Rabies virus spreads through saliva of rabid animals, usually by dog bite.
Why Do We Fall Ill – MCQs (Part 4: Q76–Q100)
Q76. Which one is a non-infectious disease?
a) Tuberculosis
b) Malaria
c) Diabetes
d) Polio
Answer: c) Diabetes
👉 Explanation: Diabetes is not caused by pathogens but due to hormonal imbalance (insulin deficiency).
Q77. Which disease is caused by deficiency of Vitamin A?
a) Night blindness
b) Rickets
c) Goitre
d) Scurvy
Answer: a) Night blindness
👉 Explanation: Vitamin A deficiency leads to poor vision in dim light (night blindness).
Q78. Which disease is prevented by the OPV vaccine?
a) Measles
b) Tuberculosis
c) Polio
d) Influenza
Answer: c) Polio
👉 Explanation: OPV (Oral Polio Vaccine) protects against poliovirus infection.
Q79. Which of the following is NOT a bacterial disease?
a) Typhoid
b) Cholera
c) Tuberculosis
d) Hepatitis
Answer: d) Hepatitis
👉 Explanation: Hepatitis is caused by virus. The rest are bacterial diseases.
Q80. Which pathogen causes measles?
a) Virus
b) Fungus
c) Bacteria
d) Protozoa
Answer: a) Virus
👉 Explanation: Measles is caused by measles virus (Morbillivirus).
Q81. Which disease is NOT sexually transmitted?
a) AIDS
b) Gonorrhoea
c) Syphilis
d) Influenza
Answer: d) Influenza
👉 Explanation: Influenza spreads by air droplets, not sexual contact. AIDS, gonorrhoea, syphilis are STDs.
Q82. Which of the following is an example of a congenital disease?
a) Cancer
b) Diabetes
c) Hole in the heart
d) Typhoid
Answer: c) Hole in the heart
👉 Explanation: Congenital diseases are present at birth (e.g., heart defects). Others are acquired later.
Q83. Which is the mode of transmission of Japanese Encephalitis?
a) Air
b) Contaminated food
c) Mosquito bite
d) Unsafe water
Answer: c) Mosquito bite
👉 Explanation: Japanese Encephalitis is a viral disease spread by mosquitoes.
Q84. Which type of diseases are cancer and diabetes?
a) Infectious
b) Acute
c) Non-infectious
d) Epidemic
Answer: c) Non-infectious
👉 Explanation: Cancer and diabetes are lifestyle/non-infectious diseases, not caused by microbes.
Q85. Which disease is prevented by DPT vaccine?
a) Diphtheria, Pertussis, Tetanus
b) Dengue, Polio, Typhoid
c) Diabetes, Pneumonia, Tuberculosis
d) Dysentery, Plague, Tetanus
Answer: a) Diphtheria, Pertussis, Tetanus
👉 Explanation: DPT vaccine provides immunity against diphtheria, pertussis (whooping cough), and tetanus.
Q86. Which of the following is a bacterial STD?
a) AIDS
b) Gonorrhoea
c) Polio
d) Dengue
Answer: b) Gonorrhoea
👉 Explanation: Gonorrhoea is caused by bacterium Neisseria gonorrhoeae. AIDS (virus), polio (virus), dengue (virus).
Q87. Which disease is also called “white plague”?
a) Malaria
b) Tuberculosis
c) Cholera
d) Influenza
Answer: b) Tuberculosis
👉 Explanation: TB was once called “white plague” because of the pale appearance of patients.
Q88. Which disease spreads by consuming undercooked pork?
a) Ascariasis
b) Taeniasis
c) Rabies
d) Rickets
Answer: b) Taeniasis
👉 Explanation: Taeniasis is caused by Taenia solium (pork tapeworm).
Q89. Which organ is affected by nephritis?
a) Heart
b) Kidney
c) Lungs
d) Liver
Answer: b) Kidney
👉 Explanation: Nephritis is inflammation of kidneys.
Q90. Which of the following is an example of a vector?
a) Air
b) Water
c) Mosquito
d) Food
Answer: c) Mosquito
👉 Explanation: A vector carries pathogens (e.g., mosquitoes spread malaria, dengue).
Q91. Which disease is caused by Clostridium tetani?
a) Tetanus
b) Typhoid
c) Tuberculosis
d) Cholera
Answer: a) Tetanus
👉 Explanation: Tetanus bacteria enter through wounds, producing toxins affecting nerves.
Q92. Which vitamin deficiency causes beriberi?
a) Vitamin A
b) Vitamin B1
c) Vitamin C
d) Vitamin D
Answer: b) Vitamin B1
👉 Explanation: Lack of Vitamin B1 (thiamine) causes beriberi, affecting nervous system.
Q93. Which disease is caused by protozoa and spread by sandfly?
a) Kala-azar
b) Malaria
c) Dengue
d) Typhoid
Answer: a) Kala-azar
👉 Explanation: Kala-azar is caused by Leishmania donovani and spread by sandfly.
Q94. Which of the following is a non-communicable disease?
a) Typhoid
b) Cancer
c) Tuberculosis
d) Cholera
Answer: b) Cancer
👉 Explanation: Cancer does not spread from person to person; it is a non-communicable disease.
Q95. Which microorganism causes leprosy?
a) Virus
b) Fungus
c) Mycobacterium leprae
d) Protozoa
Answer: c) Mycobacterium leprae
👉 Explanation: Leprosy is caused by Mycobacterium leprae (bacterium).
Q96. Which of the following diseases is NOT caused by bacteria?
a) Leprosy
b) Tuberculosis
c) Polio
d) Cholera
Answer: c) Polio
👉 Explanation: Polio is viral. Leprosy, TB, and cholera are bacterial.
Q97. Which one of the following is an airborne disease?
a) Malaria
b) Tuberculosis
c) Dengue
d) Cholera
Answer: b) Tuberculosis
👉 Explanation: TB spreads by inhaling infected droplets in air.
Q98. Which disease is caused by deficiency of calcium?
a) Osteoporosis
b) Goitre
c) Anaemia
d) Scurvy
Answer: a) Osteoporosis
👉 Explanation: Calcium deficiency weakens bones, causing osteoporosis.
Q99. Which organ is affected by meningitis?
a) Heart
b) Brain and spinal cord
c) Kidneys
d) Lungs
Answer: b) Brain and spinal cord
👉 Explanation: Meningitis is inflammation of meninges around brain and spinal cord.
Q100. Which of the following is the best method of disease prevention?
a) Antibiotics
b) Surgery
c) Good hygiene and vaccination
d) Painkillers
Answer: c) Good hygiene and vaccination
👉 Explanation: Preventing diseases through sanitation, clean food/water, and vaccination is better than treatment.
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❓ Short FAQ Section (4–5 Questions)
Q1. What is the main cause of infectious diseases?
Infectious diseases are caused by microorganisms such as bacteria, viruses, fungi, protozoa, and worms.
Q2. What is the difference between acute and chronic diseases?
Acute diseases last for a short duration (e.g., cold, flu), while chronic diseases last for a long time (e.g., TB, diabetes).
Q3. Which topics are important in the chapter “Why Do We Fall Ill” for Class 9 CBSE exams?
Key topics include health and disease, infectious and non-infectious diseases, modes of transmission, prevention, and principles of treatment.
Q4. Why are MCQs on “Why Do We Fall Ill” important for CBSE Class 9 students?
They help in quick revision, strengthen exam preparation, and are often asked in board exams and school tests.
Q5. How can students prepare effectively for this chapter?
Students should practice MCQs, review NCERT examples, learn disease causes, symptoms, prevention methods, and solve previous year exam questions.
