Extra 40 multiple-choice questions (MCQs) with answers on the chapter:13 "Why Do We Fall Ill?" for Class 9 Science (CBSE):-

1-10: Basics of Health and Disease

What is health?
a) Absence of disease
b) Complete physical, mental, and social well-being
c) Free from infections
d) All of the above
✅ Answer: (b) Complete physical, mental, and social well-being

 

Which of the following does not contribute to good health?
a) Proper nutrition
b) Regular exercise
c) Polluted environment
d) Clean drinking water
✅ Answer: (c) Polluted environment

 

Which of these is an example of a non-infectious disease?
a) Malaria
b) Tuberculosis
c) Diabetes
d) Influenza
✅ Answer: (c) Diabetes

 

Which of these diseases is caused by bacteria?
a) Malaria
b) Tuberculosis
c) AIDS
d) Dengue
✅ Answer: (b) Tuberculosis

 

Which organism is responsible for causing malaria?
a) Bacteria
b) Virus
c) Protozoa
d) Fungus
✅ Answer: (c) Protozoa

 

Which of the following is an example of a viral disease?
a) Typhoid
b) Tuberculosis
c) Polio
d) Cholera
✅ Answer: (c) Polio

 

What is the mode of transmission of common cold?
a) Air
b) Water
c) Insect bite
d) Direct contact with infected person
✅ Answer: (a) Air

 

Which of the following is a vector-borne disease?
a) Typhoid
b) AIDS
c) Malaria
d) Tuberculosis
✅ Answer: (c) Malaria

 

Which of the following can cause infectious diseases?
a) Bacteria
b) Viruses
c) Fungi
d) All of the above
✅ Answer: (d) All of the above

 

Which disease is caused by a virus?
a) Cholera
b) Typhoid
c) Measles
d) Tuberculosis
✅ Answer: (c) Measles

 

Which organ produces white blood cells (WBCs)?
a) Liver
b) Bone marrow
c) Heart
d) Lungs
✅ Answer: (b) Bone marrow

 

Vaccination helps in preventing which type of disease?
a) Non-infectious
b) Infectious
c) Genetic
d) Lifestyle
✅ Answer: (b) Infectious

 

The body's defence mechanism against diseases is called?
a) Metabolism
b) Immunity
c) Digestion
d) Circulation
✅ Answer: (b) Immunity

 

Which of the following diseases can be prevented by the BCG vaccine?
a) Polio
b) Tuberculosis
c) Malaria
d) AIDS
✅ Answer: (b) Tuberculosis

 

Which of these diseases is not spread by mosquitoes?
a) Dengue
b) Malaria
c) Typhoid
d) Chikungunya
✅ Answer: (c) Typhoid

 

Which of the following is an example of a lifestyle disease?
a) Cholera
b) Diabetes
c) Malaria
d) Tuberculosis
✅ Answer: (b) Diabetes

 

HIV primarily affects which type of cells?
a) Red blood cells
b) White blood cells
c) Liver cells
d) Nerve cells
✅ Answer: (b) White blood cells

 

Which of the following is NOT a preventive measure for communicable diseases?
a) Proper hygiene
b) Vaccination
c) Isolation of infected persons
d) Junk food consumption
✅ Answer: (d) Junk food consumption

 

Which mosquito spreads dengue fever?
a) Anopheles
b) Culex
c) Aedes
d) None of the above
✅ Answer: (c) Aedes

 

Which organ is mainly affected by tuberculosis?
a) Liver
b) Heart
c) Lungs
d) Stomach
✅ Answer: (c) Lungs

 

Which of the following is NOT a cause of non-infectious diseases?
a) Genetic disorders
b) Deficiency of nutrients
c) Virus
d) Lifestyle factors
✅ Answer: (c) Virus

 

Which of the following is a deficiency disease?
a) Malaria
b) Night blindness
c) Cholera
d) Cancer
✅ Answer: (b) Night blindness

 

Which of the following is a bacterial disease?
a) Hepatitis
b) Tuberculosis
c) Dengue
d) AIDS
✅ Answer: (b) Tuberculosis

 

What is the cause of goitre?
a) Iron deficiency
b) Iodine deficiency
c) Vitamin C deficiency
d) Lack of protein
✅ Answer: (b) Iodine deficiency

 

AIDS is caused by which virus?
a) H1N1
b) HIV
c) HPV
d) HSV
✅ Answer: (b) HIV

 

Which of these is NOT a symptom of malaria?
a) High fever
b) Chills
c) Skin rash
d) Sweating
✅ Answer: (c) Skin rash

 

Which disease affects the liver?
a) Hepatitis
b) Tuberculosis
c) Diabetes
d) Typhoid
✅ Answer: (a) Hepatitis

 

Which of these diseases is caused by a protozoan?
a) Influenza
b) Malaria
c) Cholera
d) Measles
✅ Answer: (b) Malaria

 

Which vitamin deficiency causes scurvy?
a) Vitamin A
b) Vitamin B
c) Vitamin C
d) Vitamin D
✅ Answer: (c) Vitamin C

 

Which disease is caused by a fungus?
a) Ringworm
b) Dengue
c) Polio
d) Cholera
✅ Answer: (a) Ringworm

 

31. What is the full form of AIDS?

a) Acquired Immunity Disease Syndrome
b) Acquired Immunodeficiency Syndrome
c) Auto Immune Deficiency Syndrome
d) Acquired Infectious Disease Syndrome
✅ Answer: (b) Acquired Immunodeficiency Syndrome

 

32. Which organ is primarily affected by jaundice?

a) Heart
b) Liver
c) Lungs
d) Kidney
✅ Answer: (b) Liver

 

33. Which of the following is a non-communicable disease?

a) Typhoid
b) Tuberculosis
c) Cancer
d) Influenza
✅ Answer: (c) Cancer

 

34. The major cause of peptic ulcers is a bacterium called?

a) Streptococcus
b) Helicobacter pylori
c) Staphylococcus
d) Salmonella
✅ Answer: (b) Helicobacter pylori

 

35. What is the primary cause of goitre?

a) Vitamin C deficiency
b) Iron deficiency
c) Iodine deficiency
d) Protein deficiency
✅ Answer: (c) Iodine deficiency

 

36. Which of the following diseases is caused by contaminated water?

a) Dengue
b) Typhoid
c) Measles
d) Tuberculosis
✅ Answer: (b) Typhoid

 

37. Which of the following diseases is NOT caused by a virus?

a) Polio
b) Hepatitis
c) Tuberculosis
d) AIDS
✅ Answer: (c) Tuberculosis

 

38. Which of the following is an example of an airborne disease?

a) Tuberculosis
b) Cholera
c) Typhoid
d) Malaria
✅ Answer: (a) Tuberculosis

 

39. Which nutrient deficiency causes night blindness?

a) Vitamin A
b) Vitamin B
c) Vitamin C
d) Vitamin D
✅ Answer: (a) Vitamin A

 

40. Which type of pathogen causes ringworm?

a) Bacteria
b) Virus
c) Protozoa
d) Fungus
✅ Answer: (d) Fungus