ROUTERA


Chapter 8 Human Health and Disease

Class 12th Biology Chapter MCQs


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

  • A) Tuberculosis
  • B) Malaria
  • C) Cancer
  • D) Hepatitis

Answer: C
Explanation: Cancer is a non-communicable disease as it is not caused by infectious agents and does not spread from one person to another.


2. Which of the following is the causative agent of malaria?

  • A) Virus
  • B) Bacterium
  • C) Fungus
  • D) Protozoa

Answer: D
Explanation: Malaria is caused by Plasmodium, a protozoan parasite transmitted through the bites of infected Anopheles mosquitoes.


3. Which of the following is the primary mode of transmission of HIV?

  • A) Airborne transmission
  • B) Contact with contaminated water
  • C) Sexual contact and blood transfusion
  • D) Contact with animal vectors

Answer: C
Explanation: HIV (Human Immunodeficiency Virus) is primarily transmitted through sexual contact, blood transfusions, and from mother to child during childbirth or breastfeeding.


4. Which of the following vaccines prevents cervical cancer?

  • A) BCG
  • B) Hepatitis B
  • C) HPV vaccine
  • D) DPT

Answer: C
Explanation: The HPV vaccine protects against Human Papillomavirus (HPV), which is linked to the development of cervical cancer.


5. The symptoms of tuberculosis (TB) include all of the following except:

  • A) Persistent cough
  • B) Weight loss
  • C) Diarrhea
  • D) Night sweats

Answer: C
Explanation: Diarrhea is not a symptom of tuberculosis (TB), which primarily causes respiratory symptoms like persistent cough, weight loss, and night sweats.


6. Which of the following is the correct definition of immunity?

  • A) The ability to tolerate foreign substances
  • B) The ability to defend against pathogens
  • C) The ability to acquire diseases
  • D) The ability to repair damaged tissues

Answer: B
Explanation: Immunity refers to the body's ability to defend itself against infections and diseases caused by pathogens like bacteria, viruses, and other microorganisms.


7. Which type of immunity is provided by vaccines?

  • A) Innate immunity
  • B) Active acquired immunity
  • C) Passive immunity
  • D) Natural immunity

Answer: B
Explanation: Vaccines provide active acquired immunity by stimulating the body’s immune system to produce antibodies against specific pathogens.


8. Which of the following is not a vector-borne disease?

  • A) Malaria
  • B) Dengue
  • C) Tuberculosis
  • D) Plague

Answer: C
Explanation: Tuberculosis is not transmitted by vectors but through respiratory droplets from an infected person. Malaria, dengue, and plague are all vector-borne diseases.


9. Which of the following is the causative organism of AIDS?

  • A) HIV
  • B) Hepatitis B virus
  • C) Epstein-Barr virus
  • D) Herpes simplex virus

Answer: A
Explanation: AIDS (Acquired Immunodeficiency Syndrome) is caused by the Human Immunodeficiency Virus (HIV), which attacks and weakens the immune system.


10. Which of the following diseases is caused by a deficiency of iodine?

  • A) Goiter
  • B) Rickets
  • C) Scurvy
  • D) Pellagra

Answer: A
Explanation: Goiter is caused by an iodine deficiency, leading to an enlargement of the thyroid gland.


11. Which of the following is a bacterial infection?

  • A) Malaria
  • B) Tuberculosis
  • C) AIDS
  • D) Influenza

Answer: B
Explanation: Tuberculosis is caused by the bacterium Mycobacterium tuberculosis.


12. Which of the following is a characteristic of innate immunity?

  • A) Specific response
  • B) Delayed response
  • C) Non-specific response
  • D) Long-lasting immunity

Answer: C
Explanation: Innate immunity provides a non-specific defense against pathogens and responds immediately after infection.


13. Which of the following cells are primarily responsible for the production of antibodies?

  • A) T-helper cells
  • B) Macrophages
  • C) B-cells
  • D) Cytotoxic T-cells

Answer: C
Explanation: B-cells are responsible for producing antibodies as part of the humoral immune response.


14. Which of the following diseases is caused by a virus?

  • A) Typhoid
  • B) Polio
  • C) Tuberculosis
  • D) Tetanus

Answer: B
Explanation: Polio is caused by the poliovirus, a viral infection.


15. Which of the following is a characteristic of passive immunity?

  • A) It is acquired through natural exposure
  • B) It involves the production of antibodies by the body
  • C) It provides long-lasting immunity
  • D) It is provided by the transfer of antibodies from another source

Answer: D
Explanation: Passive immunity involves the transfer of antibodies from another source, such as from mother to child during breastfeeding, providing short-term protection.


16. The causative agent of dengue fever is:

  • A) Anopheles mosquito
  • B) Aedes mosquito
  • C) Tsetse fly
  • D) Culex mosquito

Answer: B
Explanation: Dengue fever is transmitted by the Aedes mosquito, particularly Aedes aegypti.


17. Which of the following is a fungal disease?

  • A) Malaria
  • B) Ringworm
  • C) Hepatitis
  • D) Tuberculosis

Answer: B
Explanation: Ringworm is caused by fungi, specifically dermatophytes.


18. Which of the following is an example of an autoimmune disease?

  • A) Rheumatoid arthritis
  • B) Tuberculosis
  • C) Malaria
  • D) Measles

Answer: A
Explanation: Rheumatoid arthritis is an autoimmune disease in which the body’s immune system mistakenly attacks its own tissues.


19. Which of the following is a vector for the transmission of the Zika virus?

  • A) Housefly
  • B) Anopheles mosquito
  • C) Aedes mosquito
  • D) Culex mosquito

Answer: C
Explanation: The Aedes mosquito is responsible for transmitting the Zika virus, which can cause birth defects in newborns.


20. Which of the following pathogens causes the disease tuberculosis?

  • A) Mycobacterium tuberculosis
  • B) Plasmodium falciparum
  • C) Streptococcus pneumoniae
  • D) Escherichia coli

Answer: A
Explanation: Tuberculosis is caused by the bacterium Mycobacterium tuberculosis.


21. What is the role of interferons in the immune response?

  • A) Directly kill pathogens
  • B) Enhance the phagocytosis of pathogens
  • C) Prevent viral replication in cells
  • D) Stimulate the production of antibodies

Answer: C
Explanation: Interferons are proteins produced by virus-infected cells that help prevent viral replication in nearby healthy cells.


22. Which of the following diseases is characterized by the destruction of insulin-producing cells in the pancreas?

  • A) Type 1 diabetes
  • B) Type 2 diabetes
  • C) Malaria
  • D) Hypertension

Answer: A
Explanation: Type 1 diabetes is an autoimmune disease in which the immune system destroys the insulin-producing beta cells in the pancreas.


23. Which of the following is a common symptom of measles?

  • A) Sore throat
  • B) Skin rash
  • C) Vomiting
  • D) Diarrhea

Answer: B
Explanation: Measles is characterized by a skin rash, along with fever, cough, and red eyes.


24. Which type of immunity involves the production of memory cells?

  • A) Innate immunity
  • B) Active acquired immunity
  • C) Passive immunity
  • D) Natural immunity

Answer: B
Explanation: Active acquired immunity involves the production of memory cells after exposure to a pathogen, which provides long-term immunity.


25. Which of the following diseases is caused by a protozoan?

  • A) Typhoid
  • B) Malaria
  • C) Smallpox
  • D) Influenza

Answer: B
Explanation: Malaria is caused by protozoan parasites of the genus Plasmodium.


26. Which of the following is the main source of transmission of hepatitis B?

  • A) Water
  • B) Air
  • C) Contaminated food
  • D) Blood and bodily fluids

Answer: D
Explanation: Hepatitis B is transmitted through blood and bodily fluids of an infected person.


27. Which of the following cells are involved in the cell-mediated immune response?

  • A) B-cells
  • B) T-cells
  • C) Red blood cells
  • D) Neutrophils

Answer: B
Explanation: T-cells are involved in the cell-mediated immune response, which targets infected cells and tumor cells.


28. Which of the following is the function of the antigen-presenting cells?

  • A) Destroy infected cells
  • B) Present antigens to T-cells
  • C) Produce antibodies
  • D) Produce memory cells

Answer: B
Explanation: Antigen-presenting cells (APCs) process and present antigens to T-cells, triggering the immune response.


29. Which of the following is the most common method of preventing malaria?

  • A) Vaccination
  • B) Use of insecticides
  • C) Antiviral drugs
  • D) Safe drinking water

Answer: B
Explanation: Insecticides and mosquito nets are the most common methods used to prevent malaria by controlling the mosquito vector.


30. Which of the following diseases is transmitted by the Tsetse fly?

  • A) Malaria
  • B) Leishmaniasis
  • C) Sleeping sickness
  • D) Yellow fever

Answer: C
Explanation: Sleeping sickness is transmitted by the Tsetse fly and is caused by the protozoan Trypanosoma.


31. Which of the following is the causative agent of leprosy?

  • A) Mycobacterium tuberculosis
  • B) Mycobacterium leprae
  • C) Plasmodium falciparum
  • D) Salmonella typhi

Answer: B
Explanation: Leprosy is caused by the bacterium Mycobacterium leprae.


32. What is the main function of vaccines?

  • A) To treat the infection
  • B) To suppress the immune system
  • C) To stimulate the production of antibodies
  • D) To destroy the pathogens

Answer: C
Explanation: Vaccines stimulate the production of antibodies in the body, providing immunity against specific pathogens without causing the disease.


33. Which of the following is not a factor involved in the spread of diseases?

  • A) Sanitation
  • B) Water quality
  • C) Lifestyle
  • D) Immunization

Answer: D
Explanation: Immunization is a preventive measure against diseases, whereas sanitation, water quality, and lifestyle are factors that can influence the spread of diseases.


34. Which of the following statements about HIV infection is correct?

  • A) It can be transmitted through casual contact
  • B) It leads to acquired immune deficiency
  • C) It can be cured with antibiotics
  • D) It does not affect the immune system

Answer: B
Explanation: HIV (Human Immunodeficiency Virus) leads to AIDS (Acquired Immunodeficiency Syndrome) by weakening the immune system, making the body more vulnerable to infections.


35. Which of the following is not a vector for the transmission of dengue fever?

  • A) Housefly
  • B) Aedes mosquito
  • C) Culex mosquito
  • D) Tsetse fly

Answer: A
Explanation: Dengue fever is transmitted by Aedes mosquitoes, not by houseflies, Culex mosquitoes, or Tsetse flies.


36. Which of the following is the most common method of diagnosing tuberculosis?

  • A) Blood test
  • B) Skin test (Mantoux test)
  • C) Urine culture
  • D) X-ray and sputum test

Answer: D
Explanation: Tuberculosis is commonly diagnosed using X-ray and by testing sputum for the presence of the Mycobacterium tuberculosis bacterium.


37. What is the function of the immune system’s memory cells?

  • A) Destroy pathogens
  • B) Recognize and fight pathogens if re-infected
  • C) Initiate inflammation
  • D) Produce antibodies in the primary immune response

Answer: B
Explanation: Memory cells remember pathogens from previous infections, allowing the immune system to respond more quickly and effectively if the pathogen invades again.


38. Which of the following diseases is caused by a deficiency of Vitamin D?

  • A) Rickets
  • B) Scurvy
  • C) Pellagra
  • D) Beriberi

Answer: A
Explanation: Rickets is caused by a deficiency of Vitamin D, leading to weakened bones in children.


39. Which of the following is a characteristic of a pandemic?

  • A) Limited to a single country
  • B) Affects people of all age groups equally
  • C) Widespread across multiple continents or worldwide
  • D) Easily cured with antibiotics

Answer: C
Explanation: A pandemic refers to an outbreak of disease that spreads across multiple continents or worldwide, affecting a large number of people.


40. Which of the following is true about malaria?

  • A) It is caused by a bacterium
  • B) It can be transmitted by sexual contact
  • C) It is spread by the Anopheles mosquito
  • D) It is curable with antibiotics

Answer: C
Explanation: Malaria is caused by Plasmodium protozoa and is transmitted by the Anopheles mosquito.


41. Which of the following is a viral disease transmitted by the Aedes mosquito?

  • A) Malaria
  • B) Yellow fever
  • C) Typhoid
  • D) Tuberculosis

Answer: B
Explanation: Yellow fever is a viral disease transmitted by Aedes mosquitoes, similar to dengue and Zika virus.


42. Which of the following diseases is characterized by the destruction of the myelin sheath around nerve fibers?

  • A) Multiple sclerosis
  • B) Parkinson’s disease
  • C) Alzheimer’s disease
  • D) Huntington’s disease

Answer: A
Explanation: Multiple sclerosis is a disease where the immune system attacks and destroys the myelin sheath surrounding nerve fibers, affecting the nervous system.


43. Which of the following statements is true about cancer?

  • A) Cancer cells do not undergo apoptosis
  • B) Cancer is always hereditary
  • C) Cancer cells cannot grow in culture
  • D) Cancer cells do not form tumors

Answer: A
Explanation: Cancer cells evade the normal process of apoptosis (programmed cell death), allowing them to proliferate uncontrollably.


44. What is the role of macrophages in the immune system?

  • A) Produce antibodies
  • B) Directly kill infected cells
  • C) Present antigens to T-cells
  • D) Secrete cytokines

Answer: C
Explanation: Macrophages are antigen-presenting cells (APCs) that engulf pathogens and present their antigens to T-cells, triggering the immune response.


45. Which of the following is the most common cause of viral hepatitis?

  • A) Contaminated food and water
  • B) Poor hygiene
  • C) Blood and sexual contact
  • D) Inhalation of droplets

Answer: C
Explanation: Viral hepatitis (A, B, and C) is commonly transmitted through blood and sexual contact, with hepatitis A also spread by contaminated food and water.


46. What is the main cause of tuberculosis?

  • A) Virus
  • B) Fungi
  • C) Protozoa
  • D) Bacteria

Answer: D
Explanation: Tuberculosis is caused by the bacterium Mycobacterium tuberculosis.


47. Which of the following is an example of a chronic disease?

  • A) Common cold
  • B) Influenza
  • C) Hypertension
  • D) Malaria

Answer: C
Explanation: Hypertension is a chronic disease that persists over time, while diseases like common cold, influenza, and malaria are typically acute.


48. Which of the following conditions is a result of overactivity of the thyroid gland?

  • A) Hypothyroidism
  • B) Cretinism
  • C) Goiter
  • D) Hyperthyroidism

Answer: D
Explanation: Hyperthyroidism occurs when the thyroid gland produces excessive amounts of thyroid hormones, leading to symptoms like weight loss and rapid heart rate.


49. Which of the following is the causative organism of cholera?

  • A) Vibrio cholerae
  • B) Escherichia coli
  • C) Salmonella typhi
  • D) Shigella dysenteriae

Answer: A
Explanation: Cholera is caused by the bacterium Vibrio cholerae, typically transmitted through contaminated water.


50. Which of the following is a major symptom of scurvy?

  • A) Weakness and swollen joints
  • B) Pale skin and fever
  • C) Swelling in the abdomen
  • D) Decreased bone density

Answer: A
Explanation: Scurvy is caused by a deficiency of Vitamin C, leading to symptoms such as weakness, swollen joints, and gum disease.