Human Health and Diseases Class 12 NEET MCQs

The National Eligibility cum Entrance Test (NEET) is a crucial examination for medical aspirants in India. A significant portion of the NEET syllabus is dedicated to Biology, emphasizing the importance of understanding human health and diseases. To help you prepare, we’ve compiled a list of 45 Multiple Choice Questions (MCQs) on Human Health and Diseases, complete with answers and explanations. Let’s dive in!

1. Identify the pathogen responsible for causing Typhoid.

a) Virus
b) Bacteria
c) Protozoa
d) Fungi

Answer:

b) Bacteria

Explanation:

Typhoid fever is caused by the bacterium Salmonella typhi.

2. Which of the following vectors is responsible for transmitting Malaria?

a) Housefly
b) Mosquito
c) Rat
d) Cockroach

Answer:

b) Mosquito

Explanation:

The Anopheles mosquito is the vector responsible for transmitting the Plasmodium parasites that cause Malaria.

3. Which of the following is not a component of innate immunity?

a) antibodies
b) interferons
c) complement proteins
d) phagocytes

Answer:

a) antibodies

Explanation:

Antibodies are part of the adaptive immune system, not the innate immune system.

4. Histamines are released from

a) macrophages
b) T lymphocytes
c) mast cells
d) natural killer cells

Answer:

c) mast cells

Explanation:

Mast cells are known for their role in allergy and anaphylaxis, and they release histamine upon activation.

5. Natural killer cells destroy the target cell by

a) phagocytosis
b) producing antibodies
c) releasing histamines
d) creating perforin-lined pores

Answer:

d) creating perforin-lined pores

Explanation:

Natural killer cells destroy target cells by creating perforin-lined pores in the membrane of the target cell.

6. One of the unique features of adaptive immunity is

a) discrimination between self and non-self
b) interferons
c) inflammatory response
d) monocytes

Answer:

a) discrimination between self and non-self

Explanation:

Adaptive immunity has the unique ability to differentiate between self and non-self substances.

7. The function of helper T- cells is to

a) stimulate B cells
b) kill the antigen
c) kill the antibodies
d) suppress B cells

Answer:

a) stimulate B cells

Explanation:

Helper T-cells play a crucial role in stimulating B cells to produce antibodies.

8. The anti-viral proteins released by a viral attacked cell are called

a) histamines
b) pyrogens
c) interferons
d) allergens

Answer:

c) interferons

Explanation:

Interferons are proteins released by viral-infected cells to inhibit the replication of the virus.

9. Antigen-antibody complex is formed at the

a) ‘constant’ regions of light chain
b) ‘variable’ regions of light chain
c) ‘constant’ region of light and heavy chain
d) ‘variable’ region of light and heavy chain

Answer:

d) ‘variable’ region of light and heavy chain

Explanation:

The antigen-antibody complex is formed at the ‘variable’ region of both light and heavy chains where the antibody binds to the antigen.

10. Function of immunoglobulin IgA is

a) protection from inhaled pathogens
b) activation of B cells
c) mediator in allergic response
d) stimulation of complement system

Answer:

a) protection from inhaled pathogens

Explanation:

Immunoglobulin IgA is found in mucous membranes and helps protect against inhaled pathogens.

11. The most abundant immunoglobulin class is of

a) IgA
b) IgD
c) IgE
d) IgG

Answer:

d) IgG

Explanation:

Immunoglobulin G (IgG) is the most abundant immunoglobulin class in the serum.

12. The secondary immune response is due to

a) memory cells
b) clone cells
c) T cells
d) B cells

Answer:

a) memory cells

Explanation:

The secondary immune response is faster and stronger due to the presence of memory cells from a previous exposure.

13. The primary lymphoid organs are

a) lymph nodes
b) spleen
c) bone marrow
d) tonsils

Answer:

c) bone marrow

Explanation:

The primary lymphoid organs, where lymphocytes are formed and mature, include the bone marrow and thymus.

14. What did Dr. Jenner inoculate in the boy for the first time?

a) live cowpox virus
b) dead cowpox virus
c) live small pox virus
d) dead small pox virus

Answer:

a) live cowpox virus

Explanation:

Dr. Edward Jenner inoculated a boy with material taken from a cowpox sore to demonstrate immunity to smallpox.

15. To protect a person against tetanus, inoculation of one of the following would save life

a) attenuated organisms
b) killed tetanus bacteria
c) tetanus antibodies
d) dead bacteria

Answer:

c) tetanus antibodies

Explanation:

Tetanus antibodies, given as tetanus immunoglobulin, can provide immediate, short-term protection against tetanus.

16. The cells that actually release the antibodies are

a) helper T cells
b) cytotoxic T cells
c) plasma cells
d) pyrogens

Answer:

c) plasma cells

Explanation:

Plasma cells, also known as effector B cells, are the white blood cells that produce antibodies as part of the body’s immune response.

17. The antigen-antibody reaction during allergies releases

a) interferons
b) pyrogens
c) allergens
d) histamines

Answer:

d) histamines

Explanation:

During an allergic reaction, the antigen-antibody interaction can trigger cells to release histamines which cause the symptoms of an allergy.

18. The following blood transfusion would lead to clotting due to incompatibility

a) A given to AB
b) O given to A
c) AB given to A
d) B given to B

Answer:

c) AB given to A

Explanation:

Blood type AB has both A and B antigens, so if it’s transfused to a person with blood type A, the B antigens would be recognized as foreign, potentially leading to a clotting reaction.

19. Haemolytic disease of the newborn (HDN) occurs when

a) Rh- mother bears Rh+ foetus
b) Rh+ mother bears Rh- foetus
c) O+ mother bears A+ foetus
d) O+ mother bears foetus

Answer:

a) Rh- mother bears Rh+ foetus

Explanation:

HDN can occur when an Rh- mother has been sensitized to Rh+ blood, and carries an Rh+ foetus, potentially leading to an immune response against the foetal red blood cells.

20. Immunodeficiency can result from which of the following

a) gene mutation
b) infection
c) malnutrition
d) all of the above

Answer:

d) all of the above

Explanation:

Immunodeficiency can result from genetic mutations, infections that damage the immune system, or malnutrition which can prevent the immune system from functioning properly.

21. HIV attacks which of the following?

a) B cells
b) T cells
c) antigen presenting cells
d) T- helper cells

Answer:

d) T- helper cells

Explanation:

HIV primarily attacks T-helper cells, which are crucial for the activation of other immune cells.

22. Which of the following properties of acquired immunity is the basis of vaccination?

a) specificity
b) diversity
c) memory
d) discrimination between self and non-self

Answer:

c) memory

Explanation:

Vaccination works by training the immune system to remember specific pathogens, allowing for a quicker and stronger response upon subsequent exposure.

23. The following disease is an autoimmune disease

a) multiple sclerosis
b) malaria
c) tetanus
d) cholera

Answer:

a) multiple sclerosis

Explanation:

Multiple sclerosis is an autoimmune disease where the immune system attacks the protective sheath (myelin) that covers nerve fibers.

24. Human immunodeficiency virus (HIV) contains

a) reverse transcriptase
b) DNA
c) double-stranded RNA
d) nuclear membrane

Answer:

a) reverse transcriptase

Explanation:

HIV contains reverse transcriptase, an enzyme that transcribes its RNA genome into DNA which is then integrated into the host cell’s genome.

25. Which one of the following is a synthetic drug?

a) morphine
b) amphetamines
c) cocaine
d) charas

Answer:

b) amphetamines

Explanation:

Amphetamines are synthetic drugs that act as stimulants to the central nervous system.

26. Which one of the following is not a derivative of opium?

a) morphine
b) codeine
c) heroin
d) cocaine

Answer:

d) cocaine

Explanation:

Cocaine is derived from the coca plant, not from opium.

27. Amphetamines have the following effect on the body.

a) cause drowsiness
b) bring hallucinations
c) stimulate the body
d) depress the body

Answer:

c) stimulate the body

Explanation:

Amphetamines are stimulants that increase energy, focus, and a sense of euphoria while decreasing appetite and fatigue.

28. Which drugs are commonly called sleeping pills?

a) barbiturates
b) amphetamines
c) opiate narcotics
d) LSD

Answer:

a) barbiturates

Explanation:

Barbiturates are often used as sleeping pills due to their sedative effects.

29. Which one of the following is a psychedelic drug?

a) opium
b) LSD
c) cocaine
d) morphine

Answer:

b) LSD

Explanation:

LSD (lysergic acid diethylamide) is a psychedelic drug known for its ability to alter thoughts, perceptions, and feelings.

30. Which one of the following drugs causes hallucinations?

a) LSD
b) caffeine
c) opium
d) amphetamines

Answer:

a) LSD

Explanation:

LSD is known for causing hallucinations, altered sensations, and other psychedelic effects.

31. Which one of the following is not a teratogen?

a) thalidomide
b) amphetamines
c) german measles
d) X-rays

Answer:

b) amphetamines

Explanation:

While amphetamines can have negative effects, they are not classified as teratogens which are substances that cause malformation of an embryo or fetus.

32. Which one of the following is not an effect of tobacco?

a) blood vessels are dilated
b) blood pressure increases
c) nerve cells are stimulated
d) heartbeat increases

Answer:

a) blood vessels are dilated

Explanation:

Tobacco use can lead to constricted blood vessels, increased blood pressure, stimulated nerve cells, and an increased heart rate.

33. Which one of the following is not an example of a monophyletic taxon?

a) The first fish species and every living organism that looks like a fish.
b) The first mammal species and all its descendants.
c) The first bird species and all its descendants.
d) All of the above.

Answer:

a) The first fish species and every living organism that looks like a fish.

Explanation:

A monophyletic group includes a common ancestor and all of its descendants. The first option does not meet this criterion as it bases the group on appearance rather than evolutionary relationships.

34. What type of immunity is provided by vaccination?

a) Active immunity
b) Passive immunity
c) Innate immunity
d) Acquired immunity

Answer:

a) Active immunity

Explanation:

Vaccination provides active immunity by stimulating the body’s immune system to recognize and fight off specific pathogens.

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

a) Tuberculosis
b) Influenza
c) Diabetes
d) Hepatitis

Answer:

c) Diabetes

Explanation:

Diabetes is a non-communicable disease as it is not transmitted from person to person.

36. Which cells are primarily attacked by HIV?

a) B cells
b) T cells
c) Red blood cells
d) White blood cells

Answer:

b) T cells

Explanation:

HIV primarily attacks CD4+ T cells, which are a type of immune cell crucial for combating infections.

37. Identify the causative agent of common cold.

a) Rhinovirus
b) Coronavirus
c) Influenzavirus
d) Adenovirus

Answer:

a) Rhinovirus

Explanation:

The common cold is most often caused by the rhinovirus.

38. Which of the following diseases is characterized by the inflammation of the liver?

a) Tuberculosis
b) Hepatitis
c) Malaria
d) Typhoid

Answer:

b) Hepatitis

Explanation:

Hepatitis is characterized by inflammation of the liver, often caused by viral infections.

39. Which disease is caused by a deficiency of insulin?

a) Diabetes Mellitus
b) Diabetes Insipidus
c) Goitre
d) Rickets

Answer:

a) Diabetes Mellitus

Explanation:

Diabetes Mellitus is caused by a deficiency of insulin or a lack of response to insulin.

40. Which of the following is considered a secondary lymphoid organ?

a) Thymus
b) Bone marrow
c) Lymph nodes
d) Spleen

Answer:

c) Lymph nodes

Explanation:

Secondary lymphoid organs are where lymphocytes are activated by antigens. Lymph nodes are an example of secondary lymphoid organs, while thymus and bone marrow are primary lymphoid organs.

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

a) Malaria
b) Tuberculosis
c) AIDS
d) Measles

Answer:

a) Malaria

Explanation:

Malaria is caused by the protozoan parasites belonging to the genus Plasmodium.

42. What type of pathogen is responsible for causing tuberculosis?

a) Virus
b) Bacteria
c) Protozoa
d) Fungus

Answer:

b) Bacteria

Explanation:

Tuberculosis is caused by the bacterium Mycobacterium tuberculosis.

43. Which of the following is an autoimmune disease?

a) Rheumatoid arthritis
b) Common cold
c) Influenza
d) Hepatitis

Answer:

a) Rheumatoid arthritis

Explanation:

Rheumatoid arthritis is an autoimmune disease where the body’s immune system mistakenly attacks its own tissues, particularly the joints.

44. Which type of cells produces antibodies?

a) T cells
b) B cells
c) Phagocytes
d) Macrophages

Answer:

b) B cells

Explanation:

B cells, also known as B lymphocytes, are responsible for producing antibodies as a part of the immune response.

45. Which of the following diseases is caused by a helminth?

a) Malaria
b) Ascariasis
c) Tuberculosis
d) AIDS

Answer:

b) Ascariasis

Explanation:

Ascariasis is caused by the helminth (worm) Ascaris lumbricoides.

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