Chapter 7: Human Health and Diseases — Online MCQ Test
BIOLOGY · Grade 12 · CBSE(NCERT)
Practice Chapter 7: Human Health and Diseases with a free chapter-wise online MCQ test.
This chapter covers: Human Health Immunity Innate Immunity Acquired Immunity Malaria Typhoid Pneumonia Filariasis Cancer HIV AIDS Vaccination Drug Abuse Alcohol Abuse.
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter 7: Human Health and Diseases — Important Questions & Answers
Which of the following best defines health according to the NCERT context?
- A. Absence of any disease only
- B. A state of complete physical, mental and social well-being
- C. Ability to work continuously without rest
- D. Having strong immunity against all pathogens
Answer: B. A state of complete physical, mental and social well-being
Health is not merely the absence of disease; it includes physical, mental and social well-being.
Health is not merely the absence of disease; it includes physical, mental and social well-being.
Typhoid fever in humans is caused by which pathogen?
- A. Plasmodium vivax
- B. Salmonella typhi
- C. Streptococcus pneumoniae
- D. Wuchereria bancrofti
Answer: B. Salmonella typhi
Typhoid is a bacterial disease caused by Salmonella typhi.
Typhoid is a bacterial disease caused by Salmonella typhi.
The vector that transmits malaria to humans is:
- A. Female Anopheles mosquito
- B. Male Anopheles mosquito
- C. Female Culex mosquito
- D. Aedes mosquito
Answer: A. Female Anopheles mosquito
Malaria is transmitted by the bite of an infected female Anopheles mosquito.
Malaria is transmitted by the bite of an infected female Anopheles mosquito.
Pneumonia mainly affects which part of the human body?
- A. Liver
- B. Alveoli of lungs
- C. Small intestine
- D. Lymph vessels of limbs
Answer: B. Alveoli of lungs
Pneumonia infects the alveoli of the lungs, causing them to get filled with fluid.
Pneumonia infects the alveoli of the lungs, causing them to get filled with fluid.
Which of the following is an example of a physiological barrier of innate immunity?
- A. Skin
- B. Acid in the stomach
- C. Natural killer cells
- D. Interferons
Answer: B. Acid in the stomach
Stomach acid is a physiological barrier because it prevents microbial growth by creating an acidic environment.
Stomach acid is a physiological barrier because it prevents microbial growth by creating an acidic environment.
A person receives readymade antibodies against a pathogen. This is an example of:
- A. Active immunity
- B. Passive immunity
- C. Cell-mediated immunity
- D. Innate immunity only
Answer: B. Passive immunity
Passive immunity occurs when ready-made antibodies are directly given to protect an individual.
Passive immunity occurs when ready-made antibodies are directly given to protect an individual.
In organ transplantation, rejection of a graft is mainly due to:
- A. Antibiotic resistance in the graft
- B. Cell-mediated immune response of T-lymphocytes
- C. Absence of antibodies in blood plasma
- D. Excessive production of haemozoin
Answer: B. Cell-mediated immune response of T-lymphocytes
T-lymphocytes are responsible for cell-mediated immunity, which plays a major role in graft rejection.
T-lymphocytes are responsible for cell-mediated immunity, which plays a major role in graft rejection.
A mosquito bites a malaria patient and later transmits malaria to another person. Which form of Plasmodium is taken up by the mosquito from the patient?
- A. Sporozoites
- B. Gametocytes
- C. Haemozoin granules
- D. Ookinetes
Answer: B. Gametocytes
The mosquito takes up gametocytes from an infected human; fertilisation and further development occur inside the mosquito.
The mosquito takes up gametocytes from an infected human; fertilisation and further development occur inside the mosquito.
Which combination is correctly matched?
- A. Malaria - Wuchereria bancrofti - Female Culex mosquito
- B. Filariasis - Wuchereria malayi - Female Culex mosquito
- C. Typhoid - Plasmodium falciparum - Contaminated water
- D. Pneumonia - Salmonella typhi - Droplet infection
Answer: B. Filariasis - Wuchereria malayi - Female Culex mosquito
Filariasis is caused by filarial worms such as Wuchereria malayi and is transmitted by female Culex mosquitoes.
Filariasis is caused by filarial worms such as Wuchereria malayi and is transmitted by female Culex mosquitoes.
In HIV infection, why does the number of helper T-lymphocytes progressively decrease?
- A. HIV converts helper T-cells into red blood cells
- B. HIV-producing macrophages act as virus factories and infect helper T-cells
- C. Helper T-cells are destroyed only by antibiotics
- D. Helper T-cells stop forming antibodies against malaria
Answer: B. HIV-producing macrophages act as virus factories and infect helper T-cells
HIV first replicates in macrophages, which continue producing viruses that infect and reduce helper T-lymphocyte numbers.
HIV first replicates in macrophages, which continue producing viruses that infect and reduce helper T-lymphocyte numbers.