Human Health & Diseases

Topic: Immunity and Immune System; Subtopic: Types of Immunity

Keyword Definitions:

• Immunity: The ability of the body to resist harmful microorganisms or toxins through specific or nonspecific defense mechanisms.

• Innate Immunity: The natural defense mechanism present from birth that provides immediate protection against infections.

• Acquired Immunity: Immunity developed after exposure to an antigen or through vaccination.

• Cell-mediated Immunity: Immunity involving T-lymphocytes that attack infected cells directly.

• Humoral Immunity: Immunity mediated by antibodies produced by B-lymphocytes.

Lead Question - 2025

Which of the following type of immunity is present at the time of birth and is a non-specific type of defence in the human body:

(1) Acquired Immunity

(2) Innate Immunity

(3) Cell-mediated Immunity

(4) Humoral Immunity

Explanation:

Innate immunity is the natural, nonspecific defense mechanism present from birth. It forms the first line of defense against pathogens, including physical barriers like skin, chemical barriers like enzymes, and cellular defenses like phagocytes. It acts immediately upon exposure to infectious agents and does not require prior sensitization. Hence, the correct answer is Innate Immunity.

1. Which of the following is an example of innate immunity?

(1) Production of antibodies

(2) Inflammation after injury

(3) Immunization

(4) Memory cell formation

2. The specific immunity acquired after an infection is called:

(1) Innate Immunity

(2) Natural Passive Immunity

(3) Acquired Immunity

(4) Artificial Immunity

3. Which cells are primarily responsible for humoral immunity?

(1) T-lymphocytes

(2) B-lymphocytes

(3) Natural Killer cells

(4) Macrophages

4. Assertion (A): Innate immunity provides the first line of defense against pathogens.

Reason (R): It develops only after exposure to specific antigens.

(1) Both A and R are true, and R is the correct explanation of A.

(2) Both A and R are true, but R is not the correct explanation of A.

(3) A is true, but R is false.

(4) A is false, but R is true.

5. Match the following:

List-I (Component) — List-II (Function)

A. Skin — I. Phagocytosis

B. Mucus — II. Barrier Protection

C. Macrophages — III. Traps Pathogens

D. Tears — IV. Lysozyme Activity

(1) A-II, B-III, C-I, D-IV

(2) A-III, B-II, C-IV, D-I

(3) A-IV, B-I, C-II, D-III

(4) A-II, B-IV, C-III, D-I

6. The antibody-producing cells in our body are:

(1) Helper T cells

(2) Cytotoxic T cells

(3) Plasma cells

(4) Macrophages

7. Fill in the blanks:

________ immunity is achieved when antibodies are transferred from mother to baby through breast milk.

(1) Artificial Active

(2) Natural Passive

(3) Artificial Passive

(4) Natural Active

8. Choose the correct statements:

Statement I: Innate immunity acts immediately on exposure to pathogens.

Statement II: It requires antigen-specific recognition.

(1) Both statements are correct.

(2) Both statements are incorrect.

(3) Statement I is correct, Statement II is incorrect.

(4) Statement I is incorrect, Statement II is correct.

9. The process of engulfing pathogens by certain white blood cells is known as:

(1) Pinocytosis

(2) Exocytosis

(3) Phagocytosis

(4) Endocytosis

10. Which among the following does NOT contribute to innate immunity?

(1) Skin

(2) Saliva enzymes

(3) Memory cells

(4) Mucous secretions

Explanation:

Innate immunity includes general barriers like skin, mucous, tears, and phagocytes. It protects without prior exposure and lacks memory. Adaptive immunity, on the other hand, has memory and specificity. Memory cells are characteristic of acquired immunity, not innate. Therefore, the correct answer is Memory cells.

Topic: Immunity and Antibodies; Subtopic: Structure and Function of Immunoglobulins

Keyword Definitions:
• Antibody: A Y-shaped protein produced by B-cells that recognizes and binds specific antigens.
• Antigen: Any molecule capable of triggering an immune response by binding to antibodies.
• Immunoglobulin: Another term for antibody, consisting of heavy and light chains.
• Disulfide bond: A covalent link that holds antibody chains together.
• Variable region: The region of an antibody that binds to the antigen.
• Constant region: The structural region determining antibody class and effector function.

Lead Question - 2025

Identify the statement that is NOT correct.
(1) Each antibody has two light and two heavy chains.
(2) The heavy and light chains are held together by disulfide bonds.
(3) Antigen binding site is located at C-terminal region of antibody molecules.
(4) Constant region of heavy and light chains are located at C-terminus of antibody molecules.

Explanation: The antigen-binding site of an antibody is located at the N-terminal end, not the C-terminal end. Each antibody molecule consists of two heavy and two light chains connected by disulfide bonds. The constant region is indeed at the C-terminal portion, determining the antibody’s isotype and function. Hence, statement (3) is incorrect. The correct answer is option (3).

Guessed Questions:

1. Which of the following immunoglobulin types is most abundant in human plasma?
(1) IgM
(2) IgA
(3) IgG
(4) IgE
Explanation: IgG is the most abundant antibody in human plasma, accounting for about 75% of total immunoglobulins. It provides long-term protection against pathogens and crosses the placenta, providing passive immunity to the fetus. Hence, the correct answer is option (3) IgG.

2. The antibody that is first produced during a primary immune response is:
(1) IgG
(2) IgM
(3) IgA
(4) IgD
Explanation: During a primary immune response, IgM is the first immunoglobulin produced. It forms a pentamer structure, allowing high avidity binding to antigens and activating the complement system. It provides the initial defense before class switching occurs to IgG. Hence, the correct answer is option (2) IgM.

3. Which antibody is responsible for allergic reactions?
(1) IgA
(2) IgE
(3) IgG
(4) IgD
Explanation: IgE is primarily responsible for allergic reactions. It binds to receptors on mast cells and basophils, releasing histamine and other chemicals upon exposure to allergens. This leads to symptoms such as itching, swelling, and bronchoconstriction. Hence, the correct answer is option (2) IgE.

4. Which of the following pairs is correctly matched?
(1) IgA - Found in tears and saliva
(2) IgE - Provides mucosal immunity
(3) IgG - Found only in lymph
(4) IgM - Smallest immunoglobulin
Explanation: IgA is found in secretions like tears, saliva, and mucosal surfaces, providing the first line of defense at entry points of pathogens. It prevents microbial adhesion to epithelial cells. Hence, the correct answer is option (1) IgA - Found in tears and saliva.

5. Which part of the antibody determines its antigen-binding specificity?
(1) Constant region
(2) Variable region
(3) Hinge region
(4) Light chain only
Explanation: The variable region of both heavy and light chains forms the antigen-binding site. It contains unique amino acid sequences responsible for recognizing specific antigens. The constant region determines the antibody class and effector functions. Hence, the correct answer is option (2) Variable region.

6. Which immunoglobulin can cross the placenta to provide passive immunity to the fetus?
(1) IgA
(2) IgG
(3) IgM
(4) IgE
Explanation: IgG is the only immunoglobulin capable of crossing the placenta, providing passive immunity to the developing fetus. It protects newborns during early life until their immune system matures. Hence, the correct answer is option (2) IgG.

7. Assertion-Reason Type:
Assertion (A): IgM is the first antibody produced in primary immune response.
Reason (R): IgM forms a monomeric structure that binds efficiently to antigens.
(1) Both A and R are true and R is the correct explanation of A
(2) Both A and R are true but R is not the correct explanation of A
(3) A is true but R is false
(4) A is false but R is true
Explanation: IgM is indeed the first antibody produced during primary immune response, but it exists as a pentamer, not a monomer. The pentameric structure allows high avidity for antigens. Thus, A is true but R is false. Correct answer is option (3).

8. Matching Type:
Match List I with List II:
List I - Immunoglobulin Type
A. IgA
B. IgE
C. IgM
D. IgG
List II - Characteristic
I. Allergic reactions
II. First antibody in primary response
III. Mucosal immunity
IV. Crosses placenta
(1) A-III, B-I, C-II, D-IV
(2) A-I, B-IV, C-III, D-II
(3) A-IV, B-II, C-I, D-III
(4) A-II, B-I, C-IV, D-III
Explanation: IgA provides mucosal immunity, IgE mediates allergic reactions, IgM is first produced in primary response, and IgG crosses placenta. Hence, the correct matching is A-III, B-I, C-II, D-IV. Correct answer is option (1).

9. Fill in the Blanks:
The antigen-binding site of an antibody is formed by the ________ regions of heavy and light chains.
(1) Constant
(2) Variable
(3) Disulfide
(4) Terminal
Explanation: The antigen-binding site or paratope of an antibody is formed by the variable regions of both the heavy and light chains. These regions determine the specificity of antigen binding. Hence, the correct answer is option (2) Variable.

10. Choose the Correct Statements:
Statement I: IgE mediates hypersensitivity reactions.
Statement II: IgG provides mucosal immunity in saliva and tears.
(1) Both statements are correct
(2) Both statements are incorrect
(3) Only Statement I is correct
(4) Only Statement II is correct
Explanation: IgE mediates hypersensitivity or allergic reactions, while IgA, not IgG, provides mucosal immunity in saliva and tears. Therefore, only Statement I is correct. Correct answer is option (3).

Topic: Cancer; Subtopic: Characteristics and Types of Neoplastic Cells

Keyword Definitions:

• Neoplasm: An abnormal mass of tissue resulting from uncontrolled cell proliferation.

• Benign Tumor: Non-invasive tumor that remains confined to its original site.

• Malignant Tumor: Cancerous growth that invades surrounding tissues and spreads to distant sites.

• Metastasis: The process by which malignant cells spread from one part of the body to another.

• Oncogenes: Genes that promote cell growth and division; mutations in them may cause cancer.

• Carcinogens: Physical, chemical, or biological agents that cause cancer formation.

Lead Question - 2025

Neoplastic characteristics of cells refer to
A. A mass of proliferating cell
B. Rapid growth of cells
C. Invasion and damage to the surrounding tissue
D. Those confined to original location

Choose the correct answer from the options given below
(1) A, B only
(2) A, B, C only
(3) A, B, D only
(4) B, C, D only

Explanation: Neoplastic cells exhibit uncontrolled and abnormal growth forming a mass known as a neoplasm (A), show rapid proliferation (B), and invade nearby tissues causing damage (C). These are the main malignant features. Cells confined to their site of origin are benign, not neoplastic. Therefore, the correct answer is (2) A, B, C only. Neoplasia thus represents a breakdown of normal cellular control mechanisms leading to tumor formation and potential malignancy.

Guessed Questions:

1. Which of the following is a characteristic of malignant tumors?
(1) Slow growth
(2) Localized presence
(3) Ability to metastasize
(4) Encapsulation

Explanation: Malignant tumors are invasive and metastasize, spreading to distant body parts through blood or lymph. They grow rapidly, lack encapsulation, and cause tissue destruction. The correct answer is (3) Ability to metastasize. This property makes malignancies life-threatening, unlike benign tumors, which remain confined to their original site and are generally non-fatal.

2. Which of the following genes suppress tumor formation under normal conditions?
(1) Oncogenes
(2) Proto-oncogenes
(3) Tumor suppressor genes
(4) Structural genes

Explanation: Tumor suppressor genes such as p53 prevent uncontrolled cell division by repairing damaged DNA or inducing apoptosis. Mutation or loss of these genes removes cell cycle control, resulting in tumor formation. Thus, the correct answer is (3) Tumor suppressor genes, which are crucial in maintaining genomic stability and preventing neoplasia.

3. Which of the following statements is true for benign tumors?
(1) They invade surrounding tissues
(2) They metastasize
(3) They remain localized
(4) They spread through lymphatic system

Explanation: Benign tumors are localized and non-invasive. They usually remain confined to the tissue of origin and can be surgically removed. Unlike malignant tumors, they do not metastasize or invade neighboring structures. Therefore, the correct answer is (3) They remain localized, making them less dangerous than malignant growths.

4. Which virus is associated with cervical cancer in humans?
(1) Hepatitis B virus
(2) Human papillomavirus (HPV)
(3) Epstein-Barr virus
(4) Herpes simplex virus

Explanation: Human papillomavirus (HPV) causes cervical cancer by integrating viral DNA into host cells, leading to uncontrolled growth. Vaccination against HPV significantly reduces the risk of infection. Therefore, the correct answer is (2) Human papillomavirus (HPV), a major causative agent of cervical carcinoma.

5. Which carcinogen is commonly linked with lung cancer?
(1) Alcohol
(2) Nicotine
(3) Tar in cigarette smoke
(4) Asbestos only

Explanation: Cigarette smoke contains tar, benzopyrene, and other carcinogenic compounds that damage lung tissue DNA leading to cancer. Tar is the most potent among them. Therefore, the correct answer is (3) Tar in cigarette smoke. Prolonged exposure significantly increases the risk of bronchogenic carcinoma.

6. Which of the following best describes metastasis?
(1) Formation of benign tumor
(2) Spread of cancerous cells to distant sites
(3) Controlled growth of cells
(4) Repair of damaged tissue

Explanation: Metastasis refers to the spread of malignant cells from the primary tumor to other organs via blood or lymphatic circulation. This results in secondary tumor formation and worsens prognosis. Hence, the correct answer is (2) Spread of cancerous cells to distant sites, a hallmark of malignant neoplasms.

7. Assertion-Reason Type Question:
Assertion (A): Malignant tumors can invade and metastasize.
Reason (R): They have the ability to break away and enter blood or lymphatic vessels.
(1) Both A and R are true, and R is the correct explanation.
(2) Both A and R are true, but R is not the correct explanation.
(3) A is true, R is false.
(4) A is false, R is true.

Explanation: Malignant tumors are invasive and metastasize because their cells lose adhesion properties, enter circulation, and colonize new tissues. Hence, both Assertion and Reason are true, and R correctly explains A. The correct answer is (1) Both A and R are true, and R is the correct explanation.

8. Matching Type Question:
Match the following carcinogens with the type of cancer they cause:
A. Tobacco smoke — I. Lung cancer
B. UV radiation — II. Skin cancer
C. Asbestos — III. Mesothelioma
D. HPV — IV. Cervical cancer

(1) A-I, B-II, C-III, D-IV
(2) A-II, B-I, C-IV, D-III
(3) A-III, B-IV, C-II, D-I
(4) A-IV, B-I, C-III, D-II

Explanation: Tobacco smoke causes lung cancer (A–I), UV radiation leads to skin cancer (B–II), asbestos exposure leads to mesothelioma (C–III), and HPV infection causes cervical cancer (D–IV). Thus, the correct answer is (1) A–I, B–II, C–III, D–IV. These carcinogens disrupt DNA integrity and promote neoplasia.

9. Fill in the Blanks / Completion Type:
The spread of cancerous cells to distant organs through blood or lymph is called ________.
(1) Transformation
(2) Metastasis
(3) Mutation
(4) Differentiation

Explanation: The process of metastasis allows cancer cells to move from their origin to distant sites forming secondary tumors. It involves cell detachment, invasion, and colonization. Hence, the correct answer is (2) Metastasis. This feature distinguishes malignant cancers from benign growths.

10. Choose the Correct Statements:
Statement I: Benign tumors invade surrounding tissues.
Statement II: Malignant tumors spread through metastasis.
(1) Both statements are true.
(2) Both statements are false.
(3) Statement I is true, Statement II is false.
(4) Statement I is false, Statement II is true.

Explanation: Benign tumors do not invade or metastasize; they stay localized. Malignant tumors, however, show invasiveness and spread through metastasis. Thus, Statement I is false and Statement II is true. The correct answer is (4) Statement I is false, Statement II is true.

Topic: Common Human Disorders; Subtopic: Respiratory, Cardiovascular, Renal and Muscular Disorders

Keyword Definitions:
• Emphysema: A chronic respiratory disease causing damage to alveolar walls, reducing surface area for gas exchange.
• Angina Pectoris: Severe chest pain due to insufficient oxygen supply to heart muscles.
• Glomerulonephritis: Inflammation of kidney glomeruli affecting filtration.
• Tetany: Muscle spasms caused by low calcium ion (Ca++) concentration in body fluids.
• Alveoli: Tiny air sacs in the lungs where gas exchange occurs.

Lead Question – 2025
Match List - I with List - II
List - I                                          List - II
A. Emphysema                                          I. Rapid spasms in muscle due to low Ca++ in body fluid
B. Angina pectoris                                       II. Damaged alveolar walls and decreased respiratory surface
C. Glomerulonephritis                               III. Acute chest pain when not enough oxygen is reaching heart muscle
D. Tetany                                              IV. Inflammation of glomeruli of kidney
Choose the correct answer from the options given below:
(1) A-III, B-I, C-IV, D-II
(2) A-III, B-I, C-II, D-IV
(3) A-II, B-IV, C-III, D-I
(4) A-II, B-III, C-IV, D-I

Explanation:
Emphysema results from alveolar wall damage leading to reduced gas exchange surface. Angina pectoris causes acute chest pain when the heart lacks oxygen. Glomerulonephritis involves glomerular inflammation affecting filtration. Tetany results from calcium ion deficiency causing muscle spasms. Hence, the correct match is (4) A-II, B-III, C-IV, D-I. These disorders affect different body systems but share physiological significance.

Guessed Questions:

1. Single Correct Answer:
Which of the following diseases is caused by the destruction of alveolar walls in the lungs?
(1) Asthma
(2) Bronchitis
(3) Emphysema
(4) Pneumonia
Explanation:
In emphysema, the alveolar walls are destroyed, reducing the total respiratory surface area and impairing oxygen exchange. It often occurs due to smoking or chronic exposure to irritants. The correct answer is (3) Emphysema.

2. Single Correct Answer:
Angina pectoris occurs due to:
(1) Inflammation of cardiac valves
(2) Lack of oxygen to heart muscles
(3) Excess calcium in cardiac tissue
(4) Blockage in pulmonary arteries
Explanation:
Angina pectoris is severe chest pain due to a temporary deficiency of oxygen-rich blood to the heart muscles, usually caused by coronary artery narrowing. The correct answer is (2) Lack of oxygen to heart muscles.

3. Single Correct Answer:
Glomerulonephritis affects which part of the human body?
(1) Liver
(2) Kidney
(3) Lungs
(4) Heart
Explanation:
Glomerulonephritis is an inflammatory disease of the kidney glomeruli, which are the filtration units. It results in reduced urine output and presence of proteins or blood in urine. Hence, the correct answer is (2) Kidney.

4. Single Correct Answer:
Deficiency of calcium ions (Ca++) in body fluids leads to:
(1) Osteoporosis
(2) Tetany
(3) Anaemia
(4) Myasthenia
Explanation:
When calcium ion concentration falls in body fluids, nerve and muscle excitability increases, leading to spasms and cramps called tetany. This condition can arise due to hypoparathyroidism. The correct answer is (2) Tetany.

5. Single Correct Answer:
Which of the following is a symptom of Emphysema?
(1) Increased oxygen uptake
(2) Reduced gas exchange surface area
(3) Inflammation of kidney
(4) Pain in chest muscles
Explanation:
Emphysema involves damage to alveolar walls, which leads to decreased surface area for gas exchange, resulting in breathlessness and poor oxygenation. The correct answer is (2) Reduced gas exchange surface area.

6. Single Correct Answer:
Which disorder is characterized by inflammation of glomeruli in kidneys?
(1) Pyelonephritis
(2) Glomerulonephritis
(3) Nephrolithiasis
(4) Cystitis
Explanation:
Glomerulonephritis is an inflammation of glomeruli that disrupts filtration and leads to swelling and decreased urine output. It may result from bacterial infection or autoimmune reactions. Hence, the correct answer is (2) Glomerulonephritis.

7. Assertion–Reason Type:
Assertion (A): Tetany occurs due to a drop in calcium ion levels in body fluids.
Reason (R): Calcium ions are essential for the regulation of muscle contraction.
(1) Both A and R are true, and R is the correct explanation of A
(2) Both A and R are true, but R is not the correct explanation of A
(3) A is true, R is false
(4) A is false, R is true
Explanation:
Tetany results from decreased calcium ion concentration, leading to involuntary muscle spasms. Calcium regulates muscle contraction by controlling the interaction between actin and myosin. Thus, both A and R are true, and R explains A. The correct answer is (1).

8. Matching Type:
Match the following diseases with the affected organ system:
List I – Disease        List II – System Affected
A. Emphysema – (i) Respiratory system
B. Angina pectoris – (ii) Circulatory system
C. Glomerulonephritis – (iii) Excretory system
D. Tetany – (iv) Muscular system
(1) A-i, B-ii, C-iii, D-iv
(2) A-ii, B-iii, C-i, D-iv
(3) A-iv, B-i, C-ii, D-iii
(4) A-iii, B-iv, C-i, D-ii
Explanation:
Emphysema affects the respiratory system, Angina pectoris affects the circulatory system, Glomerulonephritis affects the excretory system, and Tetany involves the muscular system. Hence, the correct match is (1) A-i, B-ii, C-iii, D-iv.

9. Fill in the Blanks:
The inflammation of the glomeruli in kidneys is known as __________.
(1) Emphysema
(2) Glomerulonephritis
(3) Angina
(4) Tetany
Explanation:
Inflammation of glomeruli reduces filtration efficiency and affects urine composition, leading to the presence of protein and blood. This disease is known as Glomerulonephritis. Hence, the correct answer is (2) Glomerulonephritis.

10. Choose the Correct Statements:
Statement I: Emphysema leads to a decrease in respiratory surface area.
Statement II: Tetany is caused by high calcium ion levels in body fluids.
(1) Both statements are correct
(2) Both statements are incorrect
(3) Statement I is correct, Statement II is incorrect
(4) Statement I is incorrect, Statement II is correct
Explanation:
In emphysema, alveolar wall damage decreases respiratory surface area, reducing gas exchange efficiency. Tetany occurs due to low calcium levels, not high. Hence, Statement I is correct and Statement II is incorrect. The correct answer is (3).

Topic: Organ Transplantation; Subtopic: Immunological Basis of Transplant Rejection

Keyword Definitions:
• Organ Transplantation: The process of transferring an organ from one individual (donor) to another (recipient) to replace a damaged or non-functional organ.
• Tissue Matching: Comparison of surface antigens to minimize graft rejection risk.
• Immunosuppressants: Medicines that suppress immune activity to prevent rejection of transplanted organs.
• Rejection: Immune system’s attack against transplanted tissue or organ.

Lead Question – 2024 (Jhajjar)
Assertion (A): Some human organs like liver, kidney fail to function normally and transplantation is the only remedy to enable the patient to live a normal life.
Reason (R): Tissue matching and blood group matching are essential before undertaking any transplant and patient has to take immunosuppressant thereafter.

In the light of the above statements, choose the correct answer from the options given below:
1. Both (A) and (R) are True and (R) is the correct explanation of (A)
2. Both (A) and (R) are True but (R) is not the correct explanation of (A)
3. (A) is True but (R) is False
4. (A) is False but (R) is True

Explanation:
Organ transplantation is the replacement of a failed organ with a healthy one from a donor. Matching tissue type and blood group is crucial to avoid immune rejection. Immunosuppressants must be taken after surgery to prevent graft rejection. Both Assertion and Reason are true, and Reason correctly explains Assertion.

1. Which of the following organs cannot be transplanted?
1. Kidney
2. Heart
3. Brain
4. Liver

Explanation:
The brain cannot be transplanted because it holds all neural connections and consciousness that define individuality. Other organs like kidneys, heart, and liver can be replaced successfully with proper tissue and blood matching. Neural tissue regeneration is limited, making brain transplantation scientifically and ethically impossible. Hence, option 3 is correct.

2. Which of the following is used as an immunosuppressant in organ transplantation?
1. Cyclosporin A
2. Insulin
3. Cortisol
4. Adrenaline

Explanation:
Cyclosporin A, derived from the fungus *Trichoderma polysporum*, is the most widely used immunosuppressant. It inhibits activation of T-lymphocytes, reducing immune rejection of the transplanted organ. Drugs like insulin or adrenaline are unrelated to immune suppression. Therefore, the correct answer is Cyclosporin A, ensuring long-term graft survival in patients.

3. Graft rejection after transplantation mainly occurs due to:
1. Incompatibility between donor and recipient tissues
2. Inadequate blood supply to the graft
3. Hormonal imbalance in recipient
4. Bacterial contamination during surgery

Explanation:
Graft rejection is primarily caused by immune incompatibility between donor and recipient tissues. The recipient’s immune system identifies foreign antigens on the donor organ and attacks it. This rejection can be minimized by careful tissue matching and lifelong use of immunosuppressants. Hence, the correct answer is incompatibility between donor and recipient tissues.

4. Which of the following is a commonly transplanted organ in humans?
1. Pancreas
2. Kidney
3. Brain
4. Spleen

Explanation:
Kidney transplantation is the most common and successful type of organ transplant in humans. The human body can function with one healthy kidney, making it possible for living donors to donate one kidney. Pancreas and spleen transplants are rare, while brain transplantation is not possible. Thus, the correct answer is kidney.

5. The term “autograft” refers to:
1. Transplant between two individuals of the same species
2. Transplant from one part to another part of the same individual
3. Transplant between two different species
4. Artificial organ transplant

Explanation:
An autograft is a transplant in which tissue or organ is moved from one part of a person’s body to another part of the same individual. Since the donor and recipient are the same, there is no immune rejection. For example, skin grafting in burn patients. Therefore, option 2 is correct.

6. The first successful human heart transplant was performed by:
1. Alexis Carrel
2. Christiaan Barnard
3. Charles Drew
4. Robert Koch

Explanation:
Dr. Christiaan Barnard performed the first successful human heart transplant in 1967 in South Africa. The patient received a heart from a brain-dead donor. Although the recipient lived for only 18 days, it was a breakthrough in transplantation science, paving the way for improved surgical and immunological techniques. Hence, option 2 is correct.

7. Assertion-Reason Type:
Assertion (A): Immunosuppressants are administered after organ transplantation.
Reason (R): They strengthen the immune system to prevent infections.
1. Both (A) and (R) are True and (R) is the correct explanation of (A)
2. Both (A) and (R) are True but (R) is not the correct explanation of (A)
3. (A) is True but (R) is False
4. (A) is False but (R) is True

Explanation:
Immunosuppressants are given after organ transplantation, but they suppress the immune system, not strengthen it. Their role is to prevent the immune system from attacking the transplanted organ. Hence, Assertion is true, Reason is false. Correct answer is option 3. These drugs balance infection control and graft acceptance.

8. Matching Type:
Match the following:
A. Kidney transplant - I. Cyclosporin A
B. Graft rejection - II. Immune response
C. Immunosuppressant - III. Donor-recipient compatibility
D. Tissue matching - IV. HLA typing

1. A-III, B-II, C-I, D-IV
2. A-II, B-I, C-III, D-IV
3. A-I, B-II, C-III, D-IV
4. A-IV, B-III, C-I, D-II

Explanation:
Organ transplantation success depends on immune compatibility. Kidney transplant relies on donor-recipient compatibility, graft rejection results from immune response, Cyclosporin A acts as immunosuppressant, and tissue matching is based on HLA typing. Thus, the correct matching is A-III, B-II, C-I, D-IV, ensuring minimal graft rejection and prolonged organ survival.

9. Fill in the Blank:
The major histocompatibility complex (MHC) in humans is also called ________.
1. HLA system
2. ABO system
3. Rh system
4. HLH system

Explanation:
In humans, the Major Histocompatibility Complex (MHC) is known as the Human Leukocyte Antigen (HLA) system. It plays a crucial role in immune response and organ transplant compatibility. Each person has a unique HLA pattern that determines acceptance or rejection of a graft. Hence, the correct answer is HLA system.

10. Choose the Correct Statements:
Statement I: Tissue matching helps reduce graft rejection.
Statement II: Immunosuppressants are unnecessary after successful matching.
1. Both statements are correct
2. Both statements are incorrect
3. Statement I is correct, Statement II is incorrect
4. Statement I is incorrect, Statement II is correct

Explanation:
Tissue matching significantly reduces the chance of graft rejection but cannot eliminate it completely. Immunosuppressants remain necessary even after successful matching to maintain long-term organ survival. Therefore, Statement I is correct and Statement II is incorrect. Continuous monitoring of immune response is crucial for transplant success.

Topic: Immunity and Immune System; Subtopic: Types of Acquired Immunity

Keyword Definitions:

• Immunity: The ability of the body to resist infection or disease through antibodies or specialized cells.

• Antibodies: Protein molecules produced by B-lymphocytes that recognize and neutralize specific antigens.

• Passive immunity: Transfer of ready-made antibodies from one individual to another for immediate protection.

• Active immunity: Immunity developed when an individual’s immune system produces antibodies after exposure to antigen.

• Hyper immune serum: A serum containing high concentration of antibodies prepared from an immunized animal.

Lead Question - 2024 (Jhajjhar)
Use of hyper immune horse serum raised against a specific pathogen, given to a recipient is an example of:
1. Natural active immunity
2. Artificial active immunity
3. Natural passive immunity
4. Artificial passive immunity
Explanation: When hyper immune serum from horses containing antibodies against specific pathogens is injected into a human, it provides immediate but short-term protection. Since the antibodies are prepared outside the body and then introduced artificially, this represents artificial passive immunity. It is used for snake bite, diphtheria, and tetanus treatment. (Answer: 4)

1. Which of the following provides long-term immunity?
1. Antiserum injection
2. Antitoxin therapy
3. Vaccination
4. Passive immunization
Explanation: Vaccination triggers the immune system to produce specific memory cells, leading to long-term protection. It introduces antigens in a controlled way, enabling the body to develop active immunity. Passive immunization or antisera provide immediate but temporary protection without immune memory formation. (Answer: 3)

2. Immunity developed after recovery from an infection is termed:
1. Natural active immunity
2. Artificial passive immunity
3. Artificial active immunity
4. Natural passive immunity
Explanation: When a person recovers from a natural infection, their immune system has generated antibodies and memory cells against the pathogen. This provides protection against future infections by the same organism. Hence, it is called natural active immunity. (Answer: 1)

3. Transfer of antibodies from mother to fetus through placenta represents:
1. Natural active immunity
2. Artificial passive immunity
3. Natural passive immunity
4. Artificial active immunity
Explanation: Maternal antibodies (especially IgG) cross the placenta and provide protection to the newborn during early life. This process involves natural transfer of ready-made antibodies and therefore is classified as natural passive immunity. (Answer: 3)

4. Vaccination against polio represents:
1. Artificial active immunity
2. Artificial passive immunity
3. Natural passive immunity
4. Natural active immunity
Explanation: Polio vaccine introduces killed or attenuated pathogens into the body, which stimulates the immune system to produce antibodies and memory cells without causing disease. Thus, the body develops artificial active immunity, ensuring long-term protection against polio infection. (Answer: 1)

5. Which of the following pairs is correctly matched?
1. Antiserum – Artificial active immunity
2. Vaccination – Natural active immunity
3. Maternal antibodies – Natural passive immunity
4. Snake antivenom – Natural active immunity
Explanation: Maternal antibodies are naturally transferred through placenta or breast milk, giving the newborn temporary immunity. Hence, maternal antibodies provide natural passive immunity. Antisera like antivenom represent artificial passive immunity. (Answer: 3)

6. Which immunoglobulin crosses the placenta to provide immunity to the fetus?
1. IgA
2. IgG
3. IgE
4. IgM
Explanation: IgG is the smallest antibody that can cross the placental barrier and provide immunity to the fetus against certain infections. It offers temporary protection until the infant’s immune system matures. Other antibodies like IgA and IgM do not cross the placenta. (Answer: 2)

Assertion–Reason Question
7. Assertion (A): Antivenom provides immediate relief from snake bite.
Reason (R): Antivenom contains preformed antibodies against the venom antigen.
1. Both A and R are true, and R is the correct explanation of A.
2. Both A and R are true, but R is not the correct explanation of A.
3. A is true, but R is false.
4. A is false, but R is true.
Explanation: Antivenom gives immediate protection by neutralizing venom toxins directly. This happens because it contains preformed antibodies raised in horses or other animals against the specific venom. Thus, both statements are true, and R correctly explains A. (Answer: 1)

Matching Type Question
8. Match the following:
A. Natural active immunity — i. After vaccination
B. Artificial passive immunity — ii. After serum injection
C. Natural passive immunity — iii. From mother to child
D. Artificial active immunity — iv. After recovery from disease
1. A-iv, B-ii, C-iii, D-i
2. A-iii, B-i, C-ii, D-iv
3. A-i, B-iii, C-iv, D-ii
4. A-ii, B-iv, C-i, D-iii
Explanation: Natural active immunity develops after disease recovery (A-iv), artificial passive through antiserum (B-ii), natural passive via maternal transfer (C-iii), and artificial active by vaccination (D-i). These types ensure either long-term or short-term protection depending on antibody source. (Answer: 1)

Fill in the Blanks / Completion Question
9. ________ immunity results when antibodies are introduced into the body from an external source.
1. Active
2. Passive
3. Cell-mediated
4. Innate
Explanation: When antibodies are injected directly through antiserum or antitoxin, protection is immediate and temporary, known as passive immunity. It does not involve the immune system producing antibodies or memory cells. (Answer: 2)

Choose the Correct Statements
10. Statement I: Passive immunity provides immediate protection.
Statement II: Active immunity provides lifelong memory response.
1. Both statements are correct.
2. Both statements are incorrect.
3. Statement I is correct, Statement II is incorrect.
4. Statement I is incorrect, Statement II is correct.
Explanation: Passive immunity acts instantly because antibodies are ready-made, while active immunity develops slowly but provides lasting protection due to memory cell formation. Thus, both statements are correct, describing their distinct immune roles. (Answer: 1)

Topic: Immune System; Subtopic: Primary Lymphoid Organs

Keyword Definitions:
• Bone marrow: A soft tissue found inside bones where all blood cells, including lymphocytes, are produced.
• Thymus: A primary lymphoid organ where T-lymphocytes mature and differentiate.
• Lymphocytes: White blood cells that play a vital role in immune defense.
• Primary lymphoid organs: Organs where lymphocytes originate and mature, mainly bone marrow and thymus.
• Microenvironment: The specific internal environment supporting cell development and differentiation.

Lead Question (2024)

Given below are two statements:
Statement I: Bone marrow is the main lymphoid organ where all blood cells including lymphocytes are produced.
Statement II: Both bone marrow and thymus provide micro environments for the development and maturation of T-lymphocytes.

In the light of the above statements, choose the most appropriate answer from the options given below:
(1) Both Statement I and statement II are incorrect
(2) Statement I is correct but statement II is incorrect
(3) Statement I is incorrect but statement II is correct
(4) Both statement I and statement II are correct

Explanation:
The correct answer is (2). Bone marrow is indeed the main lymphoid organ producing all blood cells, including lymphocytes. However, thymus alone provides the microenvironment for T-lymphocyte maturation, not bone marrow. Thus, Statement I is correct and Statement II is incorrect. Both organs are crucial for immune cell development and immune system functioning.

Guessed Questions:

1. Which of the following organs is not a primary lymphoid organ?
(1) Bone marrow
(2) Thymus
(3) Spleen
(4) None of the above

Explanation: The correct answer is (3). The spleen is a secondary lymphoid organ, responsible for filtering blood and mounting immune responses. Bone marrow and thymus are primary lymphoid organs where lymphocyte formation and maturation occur before they migrate to secondary lymphoid organs.

2. In which organ do B-lymphocytes mature?
(1) Thymus
(2) Bone marrow
(3) Spleen
(4) Lymph nodes

Explanation: The correct answer is (2). B-lymphocytes mature within the bone marrow, while T-lymphocytes mature in the thymus. This distinction is essential for understanding the adaptive immune system and the origin of humoral and cell-mediated immunity.

3. Assertion-Reason Type:
Assertion (A): Thymus is the site of T-cell maturation.
Reason (R): T-cells mature in the bone marrow and migrate to the thymus for activation.
(1) Both A and R are true, and R is the correct explanation
(2) Both A and R are true, but R is not the correct explanation
(3) A is true, but R is false
(4) A is false, but R is true

Explanation: The correct answer is (3). T-cells mature in the thymus, but not in the bone marrow. The thymus provides the environment for selection and differentiation of T-cells essential for immune function.

4. Match List I with List II:
List I - Organs
A. Bone marrow
B. Thymus
C. Spleen
D. Lymph nodes

List II - Function
I. T-cell maturation
II. Blood filtration
III. Lymphocyte production
IV. Antigen trapping

(1) A–III, B–I, C–II, D–IV
(2) A–I, B–II, C–III, D–IV
(3) A–II, B–III, C–IV, D–I
(4) A–IV, B–III, C–II, D–I

Explanation: The correct answer is (1). Bone marrow produces lymphocytes, thymus is responsible for T-cell maturation, spleen filters blood, and lymph nodes trap antigens. These functions form the structural basis of the human immune system.

5. Fill in the Blanks:
__________ provides the microenvironment for the maturation of T-lymphocytes.
(1) Bone marrow
(2) Spleen
(3) Thymus
(4) Lymph nodes

Explanation: The correct answer is (3). The thymus is the primary lymphoid organ that supports T-cell maturation. Immature T-cells enter the thymus from bone marrow and undergo selection processes ensuring immunity without autoimmunity.

6. Choose the correct statements:
Statement I: Bone marrow is the site for lymphocyte formation.
Statement II: Thymus is essential for T-cell maturation.
(1) Both statements are correct
(2) Only Statement I is correct
(3) Only Statement II is correct
(4) Both statements are incorrect

Explanation: The correct answer is (1). Both bone marrow and thymus are primary lymphoid organs responsible for lymphocyte development and T-cell maturation, respectively, forming the foundation of adaptive immunity.

7. Which of the following decreases in size after puberty?
(1) Spleen
(2) Thymus
(3) Bone marrow
(4) Lymph nodes

Explanation: The correct answer is (2). The thymus is large during childhood but shrinks after puberty (a process called involution). However, it continues to produce T-cells at a reduced rate throughout adult life.

8. Which cells mature in the thymus and play a key role in cell-mediated immunity?
(1) B-lymphocytes
(2) T-lymphocytes
(3) Macrophages
(4) Neutrophils

Explanation: The correct answer is (2). T-lymphocytes mature in the thymus and are central to cell-mediated immunity, recognizing and destroying infected or abnormal cells.

9. The lymphoid organ responsible for the destruction of old red blood cells is:
(1) Bone marrow
(2) Spleen
(3) Thymus
(4) Lymph nodes

Explanation: The correct answer is (2). The spleen filters the blood, removes old RBCs, and also acts as a site for immune responses to blood-borne pathogens.

10. Which of the following is both a lymphoid and hematopoietic organ?
(1) Thymus
(2) Spleen
(3) Bone marrow
(4) Lymph nodes

Explanation: The correct answer is (3). Bone marrow serves as both a hematopoietic (blood-forming) and lymphoid organ, generating all blood cells, including immune cells like B-lymphocytes and precursors of T-cells.

Topic: Common Diseases and Their Pathogens; Subtopic: Bacterial, Protozoan, Fungal, and Helminthic Infections

Keyword Definitions:
• Typhoid: Bacterial infection caused by *Salmonella typhi*, transmitted through contaminated food and water.
• Leishmaniasis: Protozoan disease caused by *Leishmania donovani*, spread by sandflies.
• Ringworm: Fungal skin infection caused by *Microsporum* or *Trichophyton* species.
• Filariasis: Parasitic disease caused by *Wuchereria bancrofti*, a nematode transmitted by mosquitoes.

Lead Question – 2024

Match List I with List II
List I          List II
A. Typhoid          I. Fungus
B. Leishmaniasis      II. Nematode
C. Ringworm         III. Protozoa
D. Filariasis          IV. Bacteria

Choose the correct answer from the options given below
(1) A-IV, B-III, C-I, D-II
(2) A-III, B-I, C-IV, D-II
(3) A-II, B-IV, C-III, D-I
(4) A-I, B-III, C-II, D-IV

Explanation: The correct match is (1) A-IV, B-III, C-I, D-II. *Typhoid* is caused by the bacterium *Salmonella typhi*, *Leishmaniasis* by the protozoan *Leishmania donovani*, *Ringworm* by a fungal infection, and *Filariasis* by nematode worms like *Wuchereria bancrofti*. These diseases differ in pathogen type and transmission route.

1. Which of the following diseases is caused by a protozoan?
(1) Typhoid
(2) Ringworm
(3) Leishmaniasis
(4) Tuberculosis

Explanation: The correct answer is (3) Leishmaniasis. It is caused by *Leishmania donovani*, a protozoan parasite transmitted through sandfly bites. The disease affects the spleen, liver, and bone marrow, leading to fever, anemia, and weight loss. Protozoan diseases are generally vector-borne and require preventive vector control.

2. The causative agent of Filariasis is transmitted by:
(1) Housefly
(2) Sandfly
(3) Mosquito
(4) Tsetse fly

Explanation: The correct answer is (3) Mosquito. *Culex* and *Anopheles* mosquitoes transmit filarial larvae that develop into adult worms in lymphatic vessels, causing obstruction and swelling known as elephantiasis. Prevention involves mosquito control and diethylcarbamazine (DEC) prophylaxis to kill larvae and adult worms effectively.

3. Ringworm infection in humans affects mainly the:
(1) Liver
(2) Skin
(3) Lungs
(4) Kidney

Explanation: The correct answer is (2) Skin. Ringworm is a fungal infection that affects the skin, nails, and scalp. It presents as circular, itchy patches caused by dermatophytes such as *Trichophyton* and *Epidermophyton*. Treatment involves antifungal creams, maintaining hygiene, and avoiding sharing personal items.

4. Which bacterium causes Typhoid fever?
(1) *Streptococcus pneumoniae*
(2) *Salmonella typhi*
(3) *Vibrio cholerae*
(4) *Mycobacterium tuberculosis*

Explanation: The correct answer is (2) *Salmonella typhi*. This bacterium infects the intestinal tract and bloodstream through contaminated food or water. Symptoms include prolonged fever, weakness, abdominal pain, and rose spots on the skin. Vaccination and sanitation are key preventive measures against typhoid infection.

5. Which of the following diseases is transmitted through insect bites?
(1) Cholera
(2) Typhoid
(3) Leishmaniasis
(4) Tuberculosis

Explanation: The correct answer is (3) Leishmaniasis. It spreads through bites of infected female *Phlebotomus* sandflies. The parasite multiplies in macrophages and affects the skin or internal organs. Preventive measures include using insect repellents, insecticidal sprays, and protective clothing to reduce contact with sandflies.

6. Which of the following pairs is incorrectly matched?
(1) Ringworm – Fungus
(2) Filariasis – Nematode
(3) Typhoid – Protozoan
(4) Leishmaniasis – Protozoan

Explanation: The correct answer is (3) Typhoid – Protozoan. Typhoid is caused by a bacterium, *Salmonella typhi*, not a protozoan. It spreads through contaminated food or water, while protozoan diseases like malaria and leishmaniasis are transmitted through insect vectors. Understanding pathogen types aids in accurate diagnosis and treatment.

7. Assertion-Reason Type Question
Assertion (A): Filariasis causes swelling in limbs and genital organs.
Reason (R): It is caused by the blockage of lymphatic vessels by parasitic worms.
(1) Both A and R are true, and R is the correct explanation of A
(2) Both A and R are true, but R is not the correct explanation of A
(3) A is true, R is false
(4) A is false, R is true

Explanation: The correct answer is (1). Filariasis, caused by *Wuchereria bancrofti* and *Brugia malayi*, leads to lymphatic obstruction due to accumulation of adult worms. This causes fluid buildup and chronic swelling known as elephantiasis. The reason correctly explains the assertion, linking pathology to parasitic infection.

8. Matching Type Question
Match the disease with its causative organism:
A. Malaria      I. *Leishmania donovani*
B. Kala-azar     II. *Plasmodium vivax*
C. Filariasis     III. *Wuchereria bancrofti*
(1) A-II, B-I, C-III
(2) A-I, B-II, C-III
(3) A-III, B-II, C-I
(4) A-II, B-III, C-I

Explanation: The correct answer is (1). *Plasmodium vivax* causes malaria, *Leishmania donovani* causes kala-azar, and *Wuchereria bancrofti* causes filariasis. These parasites belong to protozoa and nematodes transmitted by insect vectors such as mosquitoes and sandflies, leading to severe tropical diseases in humans.

9. Fill in the Blanks Type Question
________ is the test used for diagnosis of typhoid fever.
(1) Widal test
(2) ELISA test
(3) Western blot test
(4) Mantoux test

Explanation: The correct answer is (1) Widal test. It detects antibodies against *Salmonella typhi* antigens (O and H) in the patient’s serum. A significant rise in antibody titers confirms infection. It is simple, affordable, and widely used for early diagnosis in endemic regions with poor sanitation.

10. Choose the Correct Statements
Statement I: Leishmaniasis is transmitted by mosquitoes.
Statement II: Filariasis is caused by *Wuchereria bancrofti*.
(1) Both statements are true
(2) Both statements are false
(3) Statement I is false, Statement II is true
(4) Statement I is true, Statement II is false

Explanation: The correct answer is (3). Leishmaniasis is transmitted by sandflies, not mosquitoes. Filariasis is indeed caused by *Wuchereria bancrofti*. Understanding the correct disease-vector relationship is essential for prevention and effective vector control strategies to reduce the spread of tropical parasitic infections.

Topic: Common Human Diseases; Subtopic: Infectious and Non-infectious Disorders

Keyword Definitions:

• Common Cold: A viral infection of the respiratory tract caused mainly by Rhinovirus, characterized by nasal congestion, sneezing, and sore throat.

• Haemozoin: A brown pigment formed by Plasmodium during the breakdown of hemoglobin in red blood cells, responsible for periodic fever in malaria.

• Widal Test: A diagnostic test used to detect typhoid fever caused by Salmonella typhi by identifying antibodies against the O and H antigens.

• Allergy: A hypersensitivity reaction of the immune system to normally harmless substances such as dust, pollen, or certain foods.

• Pathogen: A microorganism like bacteria, virus, fungus, or parasite that causes disease in a host organism.

Lead Question - 2024
Match List I with List II
A. Common cold  I. Plasmodium
B. Haemozoin  II. Typhoid
C. Widal test  III. Rhinovirus
D. Allergy  IV. Dust mites
Choose the correct answer from the options given below:
(1) A-I, B-III, C-II, D-IV
(2) A-III, B-I, C-II, D-IV
(3) A-IV, B-II, C-III, D-I
(4) A-II, B-IV, C-III, D-I

Explanation: The correct answer is (2). The common cold is caused by Rhinovirus, haemozoin is produced by Plasmodium during malaria infection, the Widal test detects typhoid caused by Salmonella typhi, and allergy is often triggered by dust mites or pollen. Each disorder demonstrates different pathogen types and immune responses in the body.

1. Which organism is responsible for causing common cold?
(1) Plasmodium
(2) Rhinovirus
(3) Mycobacterium
(4) Salmonella
Explanation: The correct answer is (2). Common cold is caused by Rhinovirus, which infects the upper respiratory tract. It spreads through droplets or contact with contaminated surfaces. The disease is mild and self-limiting, characterized by sneezing, sore throat, nasal congestion, and fatigue, and usually resolves within a week without complications.

2. Which pigment is responsible for the fever during malaria infection?
(1) Hemoglobin
(2) Haemozoin
(3) Melanin
(4) Bilirubin
Explanation: The correct answer is (2). Haemozoin, a dark-brown crystalline pigment, is released by the malaria parasite Plasmodium when it digests hemoglobin. This pigment triggers the immune system to produce fever at regular intervals, causing the characteristic chills and sweats of malaria. It is a key diagnostic indicator of infection severity.

3. The Widal test is used to diagnose which disease?
(1) Cholera
(2) Typhoid
(3) Influenza
(4) Tuberculosis
Explanation: The correct answer is (2). The Widal test detects antibodies against the O (somatic) and H (flagellar) antigens of Salmonella typhi, the causative agent of typhoid fever. It helps confirm infection when antibody titers are significantly elevated, indicating active or recent exposure to the pathogen through contaminated food or water.

4. Which of the following is a common allergen?
(1) Dust mites
(2) Oxygen
(3) Sodium chloride
(4) Carbon dioxide
Explanation: The correct answer is (1). Dust mites are microscopic organisms that live in house dust and trigger allergic reactions in sensitive individuals. Symptoms include sneezing, itching, nasal congestion, and wheezing. Allergies arise from immune hypersensitivity to harmless substances, often involving histamine release by mast cells and basophils.

5. Which of the following pairs is correctly matched?
(1) Common cold – Bacterium
(2) Malaria – Virus
(3) Typhoid – Salmonella typhi
(4) Allergy – Plasmodium
Explanation: The correct answer is (3). Typhoid fever is caused by Salmonella typhi, a pathogenic bacterium transmitted via contaminated water or food. It infects the intestine and bloodstream, causing prolonged fever, abdominal pain, and weakness. Proper sanitation, vaccination, and hygiene are essential preventive measures against typhoid infection.

6. Which statement correctly describes Rhinovirus infection?
(1) It affects the liver
(2) It infects the lungs causing tuberculosis
(3) It causes inflammation of the nasal mucosa
(4) It results in malaria symptoms
Explanation: The correct answer is (3). Rhinovirus infects the nasal epithelium, leading to inflammation and excess mucus production. It spreads through droplets and direct contact. The infection is self-limiting, resolving within a week, and treatment focuses on rest, hydration, and symptom management rather than antibiotics, since it is viral in origin.

7. Assertion-Reason Type Question:
Assertion (A): Haemozoin is responsible for recurring fever in malaria.
Reason (R): It stimulates the release of toxins that affect the hypothalamus temperature regulation.
(1) Both A and R are true, and R is the correct explanation of A.
(2) Both A and R are true, but R is not the correct explanation of A.
(3) A is true, but R is false.
(4) Both A and R are false.
Explanation: The correct answer is (1). Haemozoin, released during the breakdown of red blood cells by Plasmodium, stimulates immune cells to release pyrogens that act on the hypothalamus, causing periodic fever. This cycle coincides with parasite multiplication, resulting in typical fever and chills during malaria episodes.

8. Matching Type Question:
Match the following diseases with their causative agents:
A. Malaria  I. Rhinovirus
B. Common Cold  II. Plasmodium
C. Typhoid  III. Salmonella typhi
D. Tuberculosis  IV. Mycobacterium tuberculosis
(1) A-II, B-I, C-III, D-IV
(2) A-I, B-II, C-III, D-IV
(3) A-II, B-IV, C-I, D-III
(4) A-III, B-II, C-IV, D-I
Explanation: The correct answer is (1). Malaria is caused by Plasmodium, common cold by Rhinovirus, typhoid by Salmonella typhi, and tuberculosis by Mycobacterium tuberculosis. Each disease exhibits unique modes of transmission and symptoms, highlighting the importance of understanding pathogenic diversity in human health.

9. Fill in the Blanks:
Haemozoin is produced during the rupture of ________ infected with ________.
(1) RBCs, Plasmodium
(2) WBCs, Rhinovirus
(3) Liver cells, Salmonella
(4) Lymphocytes, Mycobacterium
Explanation: The correct answer is (1). During malaria infection, Plasmodium multiplies inside red blood cells and digests hemoglobin, forming haemozoin pigment. When RBCs rupture, haemozoin enters the bloodstream, triggering fever and chills by stimulating immune cells. This cyclical process defines malaria’s periodic fever pattern.

10. Choose the Correct Statements:
Statement I: Allergy is caused by the release of histamine from mast cells.
Statement II: Histamine dilates blood vessels and causes allergic symptoms.
(1) Both statements are true.
(2) Both statements are false.
(3) Statement I is true, Statement II is false.
(4) Statement I is false, Statement II is true.
Explanation: The correct answer is (1). Allergic reactions are mediated by histamine, a chemical released by mast cells upon exposure to allergens. Histamine causes vasodilation, itching, redness, and inflammation, leading to symptoms like sneezing, watery eyes, and skin rashes. Antihistamines help in relieving such hypersensitivity responses.

Topic: Drugs and Alcohol Abuse; Subtopic: Types and Sources of Addictive Drugs

Keyword Definitions:
• Cocaine: A stimulant drug extracted from the leaves of Erythroxylum coca that affects the central nervous system.
• Heroin: A semi-synthetic opioid derived from morphine, highly addictive and depresses brain activity.
• Morphine: A natural narcotic alkaloid obtained from Papaver somniferum, used as a strong painkiller.
• Marijuana: A hallucinogenic drug obtained from dried leaves and flowers of Cannabis sativa.
• Sedative: A drug that induces sleep or calms mental excitement, often used in surgery.

Lead Question – 2024

Match List I with List II
List I            List II
A. Cocaine          I. Effective sedative in surgery
B. Heroin           II. Cannabis sativa
C. Morphine          III. Erythroxylum coca
D. Marijuana         IV. Papaver somniferum

Choose the correct answer from the options given below
(1) A-I, B-III, C-II, D-IV
(2) A-II, B-I, C-III, D-IV
(3) A-III, B-IV, C-I, D-II
(4) A-IV, B-III, C-I, D-II

Explanation: The correct matching is A–III, B–IV, C–I, D–II. Cocaine is obtained from Erythroxylum coca, heroin is a derivative of morphine from Papaver somniferum, morphine is a sedative and analgesic used in surgeries, and marijuana comes from Cannabis sativa. These drugs affect the nervous system differently—cocaine stimulates, heroin and morphine depress, while marijuana distorts perception.

Guessed Question 1: Which plant is the natural source of morphine?
(1) Digitalis purpurea
(2) Papaver somniferum
(3) Erythroxylum coca
(4) Cannabis sativa

Explanation: Morphine is an alkaloid derived from the latex of the opium poppy, Papaver somniferum. It is a potent analgesic used in medicine to relieve severe pain but causes dependence when misused. It depresses the central nervous system and reduces the perception of pain.

Guessed Question 2: Which of the following drugs acts as a strong CNS stimulant?
(1) Heroin
(2) Morphine
(3) Cocaine
(4) Marijuana

Explanation: Cocaine is a powerful central nervous system stimulant that increases alertness, confidence, and energy. It inhibits the reuptake of dopamine, causing euphoria. However, prolonged use results in addiction, hallucinations, and cardiovascular problems due to excessive stimulation of brain activity.

Guessed Question 3: Which of the following is correctly matched?
(1) Heroin – Stimulant
(2) Morphine – Hallucinogen
(3) Cocaine – Analgesic
(4) Marijuana – Hallucinogen

Explanation: Marijuana acts as a hallucinogen. It is derived from Cannabis sativa and contains tetrahydrocannabinol (THC), which alters perception, mood, and cognition. It produces euphoria and a sense of relaxation, but prolonged use may impair coordination and short-term memory.

Guessed Question 4: Match the following drugs with their sources:
A. Morphine  I. Cannabis sativa
B. Marijuana  II. Papaver somniferum
C. Cocaine   III. Erythroxylum coca
Choose the correct code:
(1) A-I, B-II, C-III
(2) A-II, B-I, C-III
(3) A-III, B-II, C-I
(4) A-II, B-III, C-I

Explanation: The correct answer is (2). Morphine is obtained from Papaver somniferum, marijuana from Cannabis sativa, and cocaine from Erythroxylum coca. These natural sources provide alkaloids that act on the human nervous system, producing sedative, hallucinogenic, or stimulant effects.

Guessed Question 5: Heroin is synthesized by acetylation of which compound?
(1) Cocaine
(2) Morphine
(3) Codeine
(4) Nicotine

Explanation: Heroin is a semi-synthetic derivative of morphine produced by acetylation. This process enhances lipid solubility, allowing heroin to cross the blood-brain barrier rapidly, producing an intense euphoric effect. It is highly addictive and illegal for non-medical use due to its abuse potential.

Guessed Question 6: Which of the following statements about cocaine is incorrect?
(1) It is obtained from Erythroxylum coca
(2) It acts as a depressant
(3) It stimulates the CNS
(4) It causes euphoria and confidence

Explanation: Option (2) is incorrect. Cocaine is a CNS stimulant, not a depressant. It enhances dopamine activity, producing temporary euphoria, alertness, and excitement. Prolonged use causes anxiety, heart problems, and addiction due to overstimulation of the nervous system.

Guessed Question 7 (Assertion–Reason Type):
Assertion (A): Marijuana is classified as a hallucinogen.
Reason (R): It contains THC which affects brain perception and coordination.
(1) Both A and R are true and R is the correct explanation of A
(2) Both A and R are true but R is not the correct explanation of A
(3) A is true but R is false
(4) A is false but R is true

Explanation: Both A and R are true and R correctly explains A. Marijuana contains tetrahydrocannabinol (THC), a psychoactive compound that alters sensory perception, mood, and cognition. This makes it a classic hallucinogen affecting the central nervous system.

Guessed Question 8 (Fill in the Blanks):
_________ is obtained from Erythroxylum coca and acts as a strong stimulant on the central nervous system.
(1) Heroin
(2) Cocaine
(3) Morphine
(4) Marijuana

Explanation: Cocaine is the correct answer. It is derived from Erythroxylum coca leaves and acts as a potent CNS stimulant by blocking dopamine reuptake, increasing alertness and energy. Chronic use leads to dependency and severe psychological effects.

Guessed Question 9 (Choose the Correct Statements):
Statement I: Morphine is a CNS stimulant.
Statement II: Heroin is a depressant and causes addiction.
(1) Both statements are correct
(2) Statement I is correct but Statement II is false
(3) Statement I is false but Statement II is correct
(4) Both statements are false

Explanation: The correct answer is (3). Morphine is a CNS depressant, not a stimulant, while heroin is a depressant derived from morphine and causes addiction by reducing neuronal activity and inducing euphoria and drowsiness.

Guessed Question 10: Which of the following is not a hallucinogenic drug?
(1) LSD
(2) Marijuana
(3) Morphine
(4) Mescaline

Explanation: Morphine is not hallucinogenic; it is a depressant. LSD, marijuana, and mescaline cause hallucinations by altering neurotransmission. Morphine, obtained from the opium poppy, reduces pain sensation and induces sleep but does not cause perceptual distortions.

Topic: Immunity and Autoimmune Disorders; Subtopic: Mechanism and Examples of Autoimmune Diseases

Keyword Definitions:
• Autoimmune disorder: A condition where the immune system attacks the body’s own tissues.
• Myasthenia gravis: An autoimmune disease causing muscle weakness due to antibodies blocking acetylcholine receptors.
• Rheumatoid arthritis: Chronic inflammation of joints caused by immune attack on synovial membranes.
• Systemic Lupus Erythematosus (SLE): A systemic autoimmune disease affecting multiple organs due to autoantibodies.
• Antibody: A protein produced by B-cells to neutralize pathogens or foreign substances.

Lead Question – 2024
Which of the following are Autoimmune disorders?

A. Myasthenia gravis
B. Rheumatoid arthritis
C. Gout
D. Muscular dystrophy
E. Systemic Lupus Erythematosus (SLE)

Choose the most appropriate answer from the options given below:
(1) A, B & E only
(2) B, C & E only
(3) C, D & E only
(4) A, B & D only

Explanation: The correct answer is (1) A, B & E only. Myasthenia gravis, Rheumatoid arthritis, and Systemic Lupus Erythematosus are autoimmune diseases. They occur when the body’s immune system mistakenly attacks healthy tissues. Gout results from uric acid crystal deposition, and muscular dystrophy is a genetic disorder, not autoimmune in origin.

1. Which immune cells produce antibodies during autoimmune reactions?
(1) T-helper cells
(2) B-lymphocytes
(3) Natural killer cells
(4) Macrophages

Explanation: The correct answer is (2) B-lymphocytes. In autoimmune diseases, B-cells produce antibodies that mistakenly target the body’s own cells and tissues, causing inflammation and damage. These self-reactive antibodies play a key role in disorders like lupus and rheumatoid arthritis.

2. Which of the following is a systemic autoimmune disorder?
(1) Rheumatoid arthritis
(2) Myasthenia gravis
(3) Systemic Lupus Erythematosus
(4) Type I Diabetes Mellitus

Explanation: The correct answer is (3) Systemic Lupus Erythematosus. Unlike localized autoimmune diseases, SLE affects multiple organs such as the skin, kidneys, joints, and heart. It involves production of autoantibodies that form immune complexes, damaging tissues throughout the body.

3. Which autoimmune disorder causes muscle weakness by blocking neurotransmission at the neuromuscular junction?
(1) Myasthenia gravis
(2) Rheumatoid arthritis
(3) Addison’s disease
(4) Multiple sclerosis

Explanation: The correct answer is (1) Myasthenia gravis. In this condition, antibodies block or destroy acetylcholine receptors on muscle cells, preventing normal muscle contraction and resulting in weakness and fatigue, especially in the eyes and facial muscles.

4. Which enzyme is responsible for increased uric acid in gout?
(1) Xanthine oxidase
(2) DNA polymerase
(3) Catalase
(4) Lipase

Explanation: The correct answer is (1) Xanthine oxidase. This enzyme converts hypoxanthine to uric acid during purine metabolism. Excessive uric acid forms crystals in joints, causing inflammation and pain characteristic of gout, which is a metabolic disorder, not autoimmune.

5. Which autoimmune disorder affects insulin-producing β-cells of the pancreas?
(1) Type I Diabetes Mellitus
(2) Addison’s disease
(3) Hashimoto’s thyroiditis
(4) Myasthenia gravis

Explanation: The correct answer is (1) Type I Diabetes Mellitus. It occurs when the immune system attacks pancreatic β-cells, reducing insulin production. This results in high blood glucose and dependence on insulin therapy for glucose regulation.

6. Which of the following statements about autoimmune diseases is true?
(1) They occur due to viral infections only.
(2) They always affect the nervous system.
(3) They occur due to loss of immune tolerance to self-antigens.
(4) They are caused by nutritional deficiency.

Explanation: The correct answer is (3). Autoimmune disorders result from a loss of immune tolerance, where the immune system fails to recognize self-antigens and attacks body tissues, leading to chronic inflammation and tissue damage.

7. Assertion-Reason Type:
Assertion (A): Rheumatoid arthritis is caused by autoimmunity.
Reason (R): It occurs due to bacterial infection of joints.
(1) Both A and R are true and R is the correct explanation of A
(2) Both A and R are true but R is not the correct explanation of A
(3) A is true but R is false
(4) A is false but R is true

Explanation: The correct answer is (3). Rheumatoid arthritis is an autoimmune disease, not caused by bacterial infection. It involves the immune system attacking synovial membranes, leading to chronic inflammation and joint deformities.

8. Matching Type:
Match the following autoimmune disorders with affected organs:

A. Myasthenia gravis — I. Muscles
B. Rheumatoid arthritis — II. Joints
C. Type I Diabetes Mellitus — III. Pancreas
D. Multiple sclerosis — IV. Brain and spinal cord

(1) A-I, B-II, C-III, D-IV
(2) A-II, B-I, C-IV, D-III
(3) A-III, B-IV, C-II, D-I
(4) A-IV, B-III, C-I, D-II

Explanation: The correct answer is (1). Each disorder affects a specific organ: Myasthenia gravis (muscles), Rheumatoid arthritis (joints), Type I Diabetes (pancreas), and Multiple sclerosis (nervous system). These involve immune-mediated destruction of target tissues.

9. Fill in the Blanks:
Autoimmune disorders result from the body’s immune system attacking its own __________.
(1) Hormones
(2) Organs
(3) Tissues
(4) Enzymes

Explanation: The correct answer is (3) Tissues. In autoimmune diseases, immune cells fail to differentiate between self and non-self antigens, leading to attack on normal body tissues and resulting in chronic inflammation or organ dysfunction.

10. Choose the Correct Statements:
Statement I: Autoimmune diseases can be treated by immunosuppressive drugs.
Statement II: All autoimmune diseases are contagious.
(1) Both I and II are true
(2) Both I and II are false
(3) I is true but II is false
(4) I is false but II is true

Explanation: The correct answer is (3). Autoimmune diseases are treated using immunosuppressive drugs like corticosteroids to reduce immune activity. However, they are non-contagious and arise due to internal immune dysfunction, not infection.

Topic: Immunity; Subtopic: Body’s Barriers and Defense Mechanisms

Keyword Definitions:

• Immunity: The body's ability to resist infection and disease through defense mechanisms.

• Cytokine Barriers: Signaling proteins like interferons that help coordinate immune responses.

• Cellular Barriers: Immune cells such as neutrophils and macrophages that destroy pathogens.

• Physiological Barriers: Body fluids and secretions like tears and saliva that inhibit pathogen growth.

• Physical Barriers: Structural features like mucus coating, skin, and epithelial layers preventing pathogen entry.

• Interferons: Proteins produced by infected cells to inhibit viral replication in neighboring cells.

• Neutrophils: White blood cells that engulf and digest pathogens during immune responses.

• Macrophages: Large phagocytic cells that digest microbes and cellular debris.

• Tears and Saliva: Secretions containing enzymes and antibodies to neutralize pathogens.

• Mucus Coating: Slimy layer lining respiratory and digestive tracts to trap microbes.

• Phagocytosis: Process by which cells engulf and destroy pathogens.

Lead Question - 2023 (Manipur):

Match List-I with List-II:
List-I  List-II
(A) Cytokine barriers    (I) Mucus coating of respiratory tract
(B) Cellular barriers    (II) Interferons
(C) Physiological barriers    (III) Neutrophils and Macrophages
(D) Physical barriers    (IV) Tears and Saliva

Choose the correct answer from the options below:
1. II, III, IV, I
2. III, I, IV, II
3. III, I, II, IV
4. II, III, I, IV

Explanation: Correct answer is option 1: II, III, IV, I. Cytokine barriers (A) involve interferons (II) that coordinate antiviral responses. Cellular barriers (B) include neutrophils and macrophages (III) that engulf pathogens. Physiological barriers (C) are secretions like tears and saliva (IV) that inhibit microbial growth. Physical barriers (D) include mucus coating of respiratory tract (I) that traps microbes. These layers work together as innate immunity, providing the first line of defense. Understanding these barriers clarifies how the body prevents infection and maintains homeostasis through complementary structural and functional mechanisms.

Guessed MCQs:

1. Single Correct Answer MCQ: Interferons are primarily classified under:
(A) Cellular barriers
(B) Cytokine barriers
(C) Physical barriers
(D) Physiological barriers
Explanation: Correct answer is (B). Interferons are cytokine proteins secreted by infected cells to alert neighboring cells and inhibit viral replication. Cellular barriers involve immune cells, physical barriers are structural, and physiological barriers are secretions. Cytokines act as signaling molecules coordinating innate and adaptive immune responses, essential for antiviral defense.

2. Single Correct Answer MCQ: Neutrophils and macrophages belong to:
(A) Cytokine barriers
(B) Cellular barriers
(C) Physiological barriers
(D) Physical barriers
Explanation: Correct answer is (B). Neutrophils and macrophages are phagocytic cells that engulf and destroy pathogens. Cytokines are signaling proteins, physiological barriers include body secretions, and physical barriers include skin and mucus. Cellular barriers are the second line of innate defense, responding rapidly to microbial invasion.

3. Single Correct Answer MCQ: Tears and saliva act as:
(A) Cytokine barriers
(B) Cellular barriers
(C) Physiological barriers
(D) Physical barriers
Explanation: Correct answer is (C). Tears and saliva contain enzymes and antibodies that neutralize microbes, forming physiological barriers. Cytokines coordinate immune signaling, cellular barriers include immune cells, and physical barriers are structural. These secretions prevent pathogen colonization and are part of innate immunity.

4. Single Correct Answer MCQ: Mucus coating in the respiratory tract represents:
(A) Physical barrier
(B) Cellular barrier
(C) Physiological barrier
(D) Cytokine barrier
Explanation: Correct answer is (A). Mucus traps inhaled microbes and particles, preventing their entry into the body. Cellular barriers are immune cells, physiological barriers are secretions, and cytokines are signaling proteins. Structural defenses are first-line protective mechanisms in innate immunity.

5. Single Correct Answer MCQ: The first line of defense in immunity includes:
(A) Cytokines
(B) Phagocytic cells
(C) Physical and physiological barriers
(D) Antibodies
Explanation: Correct answer is (C). Physical and physiological barriers, like skin, mucus, tears, and saliva, prevent pathogen entry. Cytokines and phagocytic cells act as secondary defense. Antibodies are adaptive responses. First-line defense is innate, immediate, and nonspecific, providing a crucial barrier against infection.

6. Single Correct Answer MCQ: Which barrier involves signaling proteins coordinating immune response?
(A) Cellular barrier
(B) Cytokine barrier
(C) Physical barrier
(D) Physiological barrier
Explanation: Correct answer is (B). Cytokine barriers involve proteins like interferons that signal neighboring cells and modulate immune responses. Cellular barriers are immune cells, physical barriers are structural, and physiological barriers are secretions. Cytokines integrate innate and adaptive immunity efficiently.

7. Assertion-Reason MCQ:
Assertion (A): Mucus in respiratory tract prevents pathogen entry.
Reason (R): It traps microbes and dust particles before they reach lungs.
(A) Both A and R are true, and R explains A
(B) Both A and R are true, but R does not explain A
(C) A is true, R is false
(D) A is false, R is true
Explanation: Correct answer is (A). Mucus acts as a physical barrier, trapping microbes and dust particles, preventing infection. The reason correctly explains the assertion. This demonstrates the first line of defense in innate immunity and the functional role of epithelial secretions.

8. Matching Type MCQ: Match barriers with examples:
1. Cytokine    A. Interferons
2. Cellular    B. Neutrophils and macrophages
3. Physiological    C. Tears and saliva
4. Physical    D. Mucus coating
(A) 1-A, 2-B, 3-C, 4-D
(B) 1-B, 2-A, 3-D, 4-C
(C) 1-A, 2-C, 3-B, 4-D
(D) 1-D, 2-B, 3-A, 4-C
Explanation: Correct answer is (A). Cytokine barriers include interferons, cellular barriers include phagocytic cells, physiological barriers include secretions, and physical barriers include mucus coating. Each barrier provides a specific type of protection in innate immunity, acting together for pathogen defense.

9. Fill in the Blanks / Completion MCQ: Neutrophils and macrophages are examples of ______ barriers.
(A) Cytokine
(B) Cellular
(C) Physiological
(D) Physical
Explanation: Correct answer is (B). Neutrophils and macrophages are phagocytic cells that engulf pathogens, representing cellular barriers. Cytokines are signaling proteins, physiological barriers are secretions, and physical barriers prevent pathogen entry structurally. Cellular barriers form the second line of defense in innate immunity.

10. Choose the correct statements MCQ:
Statement I: Tears and saliva form physiological barriers.
Statement II: Interferons act as cytokine barriers.
(A) Only Statement I is correct
(B) Only Statement II is correct
(C) Both I and II are correct
(D) Neither I nor II is correct
Explanation: Correct answer is (C). Tears and saliva inhibit pathogen growth, forming physiological barriers. Interferons signal neighboring cells and coordinate immune responses as cytokine barriers. Both statements highlight distinct aspects of innate immunity, emphasizing the complementary nature of defense mechanisms.

Topic: Narcotics and Addiction; Subtopic: Opioids and Their Effects

Keyword Definitions:

• Diacetyl morphine: Another name for heroin, an opioid drug derived from morphine, highly addictive.

• Amphetamine: A central nervous system stimulant used medically and misused as a recreational drug.

• Barbiturate: Sedative-hypnotic drugs acting on the CNS, used to treat insomnia or seizures.

• Crack: A smokable form of cocaine, highly addictive and fast-acting.

• Smack: Street name for heroin (diacetyl morphine).

• Opioids: Class of drugs that act on opioid receptors to produce analgesia and euphoria.

• Addiction: Chronic disease characterized by compulsive drug seeking and use despite harmful consequences.

• Tolerance: Reduced response to a drug after repeated use.

• Withdrawal: Physical and mental symptoms following cessation of addictive drug use.

• Euphoria: Intense feeling of pleasure caused by drugs like opioids.

• Analgesia: Relief from pain without loss of consciousness.

Lead Question - 2023 (Manipur)

Diacetyl morphine is also called as:

1. Amphetamine

2. Barbiturate

3. Crack

4. Smack

Explanation:

Diacetyl morphine is chemically derived from morphine and is commonly known as heroin. In street language, it is referred to as "smack." It acts on the central nervous system by binding to opioid receptors, producing analgesia, euphoria, and high addiction potential. Amphetamine is a stimulant, barbiturates are sedatives, and crack is a form of cocaine. Hence, the correct answer is 4.

1. Single Correct Answer MCQ:

Which receptor type does heroin primarily act on?

1. Dopamine receptor

2. Opioid receptor

3. Adrenergic receptor

4. Serotonin receptor

Explanation:

Heroin acts on opioid receptors in the brain and spinal cord, producing analgesia, euphoria, and sedation. It does not primarily act on dopamine, adrenergic, or serotonin receptors, although opioid receptor activation indirectly affects dopamine pathways. Correct answer is 2.

2. Single Correct Answer MCQ:

Withdrawal from heroin primarily causes:

1. Euphoria

2. Anxiety and sweating

3. Analgesia

4. Sedation

Explanation:

Heroin withdrawal manifests as anxiety, sweating, nausea, muscle pain, and insomnia due to sudden cessation of opioid receptor stimulation. Euphoria and analgesia occur during use, while sedation is a drug effect, not a withdrawal symptom. Correct answer is 2.

3. Single Correct Answer MCQ:

Long-term heroin use can result in:

1. Reduced tolerance

2. Addiction

3. Improved memory

4. Enhanced immunity

Explanation:

Prolonged heroin use leads to addiction, tolerance, and dependence. It does not enhance memory or immunity. Correct answer is 2.

4. Single Correct Answer MCQ:

Which drug is a CNS stimulant?

1. Heroin

2. Amphetamine

3. Barbiturate

4. Morphine

Explanation:

Amphetamine is a central nervous system stimulant, increasing alertness and energy. Heroin and morphine are CNS depressants (opioids), and barbiturates are sedatives. Correct answer is 2.

5. Single Correct Answer MCQ:

Which street name corresponds to heroin?

1. Crack

2. Smack

3. Ice

4. Molly

Explanation:

Heroin is commonly called "smack" in street language. Crack refers to cocaine, ice is methamphetamine, and molly is MDMA. Correct answer is 2.

6. Single Correct Answer MCQ:

Heroin is classified under which category of drugs?

1. Stimulant

2. Hallucinogen

3. Opioid

4. Depressant only

Explanation:

Heroin is an opioid, producing analgesia, sedation, and euphoria by acting on opioid receptors. Though it depresses CNS, the correct pharmacological category is opioid. Stimulants and hallucinogens are different drug classes. Correct answer is 3.

7. Assertion-Reason MCQ:

Assertion (A): Heroin can cause severe addiction.

Reason (R): It binds to opioid receptors causing euphoria and tolerance.

1. Both A and R are true and R explains A

2. Both A and R are true but R does not explain A

3. A is true but R is false

4. Both A and R are false

Explanation:

Heroin causes strong euphoria by binding to opioid receptors, leading to tolerance, dependence, and severe addiction. Both assertion and reason are correct, and the reason explains the assertion. Correct answer is 1.

8. Matching Type MCQ:

Match the drug with its class:

A. Heroin — (i) Opioid

B. Amphetamine — (ii) Stimulant

C. Barbiturate — (iii) Sedative

D. Cocaine — (iv) Stimulant

1. A-(i), B-(ii), C-(iii), D-(iv)

2. A-(ii), B-(i), C-(iv), D-(iii)

3. A-(iii), B-(iv), C-(i), D-(ii)

4. A-(iv), B-(iii), C-(ii), D-(i)

Explanation:

Heroin is an opioid (i), amphetamine is a stimulant (ii), barbiturate is a sedative (iii), and cocaine is a stimulant (iv). Correct answer is 1.

9. Fill in the Blanks MCQ:

The highly addictive opioid derived from morphine is called _______.

1. Amphetamine

2. Heroin

3. Barbiturate

4. Cocaine

Explanation:

Heroin is diacetyl morphine, a highly addictive opioid derived from morphine. Amphetamines are stimulants, barbiturates are sedatives, and cocaine is a stimulant. Correct answer is 2.

10. Choose the correct statements MCQ:

Statement I: Heroin produces analgesia and euphoria.

Statement II: Amphetamines are CNS depressants.

1. Statement I only

2. Statement II only

3. Both statements are true

4. Both statements are false

Explanation:

Heroin produces analgesia and euphoria (true), while amphetamines are CNS stimulants, not depressants (false). Therefore, only Statement I is correct. Correct answer is 1.

Topic: Infectious Diseases; Subtopic: Causative Agents of Common Diseases

Keyword Definitions:

• Typhoid: A bacterial infection caused by Salmonella typhi, transmitted through contaminated food and water.

• Elephantiasis: A parasitic disease caused by filarial worms (Aschelminthes) leading to extreme swelling of limbs.

• Ringworm: A fungal infection of skin, hair, or nails caused by dermatophytes such as Microsporum.

• Malaria: A protozoan disease caused by Plasmodium species, transmitted by female Anopheles mosquitoes.

• Protozoan: Single-celled eukaryotic organisms, some of which are pathogenic to humans.

• Salmonella: Genus of rod-shaped bacteria causing typhoid and gastroenteritis.

• Aschelminthes: Phylum of parasitic worms including filarial worms.

• Microsporum: Genus of fungi causing dermatophytic infections like ringworm.

Lead Question – 2023 (Manipur)

Match List-I with List-II:
List-I    List-II
(A) Typhoid    (I) Protozoan
(B) Elephantiasis    (II) Salmonella
(C) Ringworm    (III) Aschelminthes
(D) Malaria    (IV) Microsporum
Choose the correct answer from the options given below:
1. (I) (IV) (III) (II)
2. (I) (III) (IV) (II)
3. (II) (III) (IV) (I)
4. (II) (IV) (III) (I)

Explanation: Typhoid is caused by the bacterium Salmonella typhi (II). Elephantiasis is caused by parasitic worms (Aschelminthes) (III). Ringworm is a fungal infection caused by Microsporum (IV). Malaria is a protozoan disease caused by Plasmodium species (I). Matching the correct causative agents with diseases gives the sequence (A)–(II), (B)–(III), (C)–(IV), (D)–(I). Therefore, the correct option is 3. (II) (III) (IV) (I).

1. Single Correct Answer MCQ:
Which of the following is caused by a protozoan?
1. Typhoid
2. Elephantiasis
3. Malaria
4. Ringworm
Explanation: Malaria is caused by protozoan parasites of genus Plasmodium, transmitted by female Anopheles mosquitoes. Correct answer: 3. Malaria.

2. Single Correct Answer MCQ:
Which disease is bacterial in origin?
1. Elephantiasis
2. Typhoid
3. Malaria
4. Ringworm
Explanation: Typhoid is caused by the bacterium Salmonella typhi and is transmitted via contaminated food and water. Correct answer: 2. Typhoid.

3. Single Correct Answer MCQ:
Ringworm is caused by which of the following?
1. Protozoa
2. Bacteria
3. Fungi
4. Parasitic worms
Explanation: Ringworm is a dermatophytic infection caused by fungi such as Microsporum. Correct answer: 3. Fungi.

4. Single Correct Answer MCQ:
Elephantiasis is caused by:
1. Filarial worms
2. Bacteria
3. Virus
4. Protozoa
Explanation: Elephantiasis is caused by filarial worms, belonging to phylum Aschelminthes, leading to severe swelling of limbs. Correct answer: 1. Filarial worms.

5. Single Correct Answer MCQ:
Which disease is transmitted by mosquitoes?
1. Typhoid
2. Malaria
3. Ringworm
4. Elephantiasis
Explanation: Malaria is transmitted through the bite of infected female Anopheles mosquitoes, which carry Plasmodium protozoa. Correct answer: 2. Malaria.

6. Single Correct Answer MCQ:
Which disease can be treated with antibiotics?
1. Ringworm
2. Typhoid
3. Malaria
4. Elephantiasis
Explanation: Typhoid is bacterial and can be effectively treated with antibiotics like ciprofloxacin or azithromycin. Correct answer: 2. Typhoid.

7. Assertion-Reason MCQ:
Assertion (A): Ringworm is caused by fungi.
Reason (R): Fungal infections are non-contagious.
1. Both A and R true, R explains A
2. Both A and R true, R does not explain A
3. A true, R false
4. A false, R true
Explanation: Ringworm is indeed fungal and contagious. Correct answer: 3. A true, R false.

8. Matching Type MCQ:
Match disease with type of pathogen:
A. Typhoid – (i) Bacteria
B. Elephantiasis – (ii) Helminth
C. Ringworm – (iii) Fungi
D. Malaria – (iv) Protozoa
1. A–i, B–ii, C–iii, D–iv
2. A–iv, B–i, C–ii, D–iii
3. A–ii, B–iii, C–iv, D–i
4. A–iii, B–iv, C–i, D–ii
Explanation: Typhoid is bacterial, Elephantiasis is helminthic, Ringworm is fungal, and Malaria is protozoan. Correct answer: 1.

9. Fill in the Blanks MCQ:
__________ is a fungal disease, while __________ is a bacterial disease.
1. Ringworm, Typhoid
2. Typhoid, Ringworm
3. Malaria, Elephantiasis
4. Elephantiasis, Malaria
Explanation: Ringworm is fungal, caused by Microsporum. Typhoid is bacterial, caused by Salmonella. Correct answer: 1.

10. Choose the Correct Statements MCQ:
Statement I: Malaria is transmitted by mosquitoes.
Statement II: Ringworm is caused by bacteria.
1. Both true
2. Both false
3. I true, II false
4. I false, II true
Explanation: Malaria is transmitted by Anopheles mosquitoes. Ringworm is fungal, not bacterial. Correct answer: 3.

Topic: Sexually Transmitted Infections (STIs); Subtopic: Curable and Incurable STIs

Keyword Definitions:

• Sexually Transmitted Infections (STIs): Infections transmitted primarily through sexual contact, caused by bacteria, viruses, or protozoa.

• HIV Infection: Caused by Human Immunodeficiency Virus; currently incurable but manageable with antiretroviral therapy.

• Trichomoniasis: A protozoan infection caused by Trichomonas vaginalis; curable with antibiotics like metronidazole.

• Syphilis: Bacterial STI caused by Treponema pallidum; curable with penicillin.

• Hepatitis B: Viral infection affecting the liver; no complete cure, only vaccines and antiviral treatment available.

• Genital herpes: Viral infection caused by Herpes Simplex Virus; incurable, only symptomatic management possible.

• Genital warts: Viral infection caused by Human Papillomavirus (HPV); treatment removes warts but virus persists.

Lead Question – 2023 (Manipur)

Which of the following sexually transmitted infections are completely curable?
1. HIV infection and Trichomoniasis
2. Syphilis and Trichomoniasis
3. Hepatitis-B and Genital herpes
4. Genital Herpes and Genital warts

Explanation: Trichomoniasis is caused by the protozoan Trichomonas vaginalis and is completely curable with a short course of antibiotics such as metronidazole. Syphilis, caused by Treponema pallidum, is a bacterial STI and can be completely cured with penicillin. Viral STIs such as HIV, Hepatitis-B, genital herpes, and genital warts are not completely curable, only manageable with treatment or vaccines. Therefore, among the options, the pair of STIs that are fully curable are Syphilis and Trichomoniasis. Correct answer: 2. Syphilis and Trichomoniasis.

1. Single Correct Answer MCQ:
Which STI is caused by a protozoan and is curable?
1. HIV
2. Trichomoniasis
3. Genital herpes
4. Hepatitis B
Explanation: Trichomoniasis is a protozoan infection caused by Trichomonas vaginalis and is completely curable with antibiotics. Correct answer: 2. Trichomoniasis.

2. Single Correct Answer MCQ:
Which STI is bacterial and curable with penicillin?
1. HIV
2. Syphilis
3. Genital herpes
4. Genital warts
Explanation: Syphilis is caused by the bacterium Treponema pallidum and can be completely cured using penicillin. Correct answer: 2. Syphilis.

3. Single Correct Answer MCQ:
Which of the following viral STIs is incurable?
1. Trichomoniasis
2. Syphilis
3. HIV
4. None of the above
Explanation: HIV is a viral infection and currently incurable; treatment can only manage viral load and symptoms. Correct answer: 3. HIV.

4. Single Correct Answer MCQ:
Which STI causes genital warts and is viral?
1. Hepatitis B
2. HPV infection
3. Syphilis
4. Trichomoniasis
Explanation: Genital warts are caused by Human Papillomavirus (HPV), a viral STI; treatment removes warts but the virus persists. Correct answer: 2. HPV infection.

5. Single Correct Answer MCQ:
Which of the following is managed by antiviral therapy but not cured?
1. Syphilis
2. Trichomoniasis
3. Genital herpes
4. Gonorrhea
Explanation: Genital herpes, caused by Herpes Simplex Virus, is incurable; antiviral therapy manages outbreaks but does not eradicate the virus. Correct answer: 3. Genital herpes.

6. Single Correct Answer MCQ:
Which STI is preventable by vaccination?
1. Trichomoniasis
2. Genital herpes
3. Hepatitis B
4. Syphilis
Explanation: Hepatitis B is a viral infection; although incurable, it can be prevented effectively by vaccination. Correct answer: 3. Hepatitis B.

7. Assertion-Reason MCQ:
Assertion (A): Trichomoniasis can be completely cured.
Reason (R): It is caused by a bacterial pathogen.
1. Both A and R true, R explains A
2. Both A and R true, R does not explain A
3. A true, R false
4. A false, R true
Explanation: Trichomoniasis is curable, but it is caused by a protozoan, not bacteria. Correct answer: 3. A true, R false.

8. Matching Type MCQ:
Match the STI with its causative agent:
A. Syphilis – (i) Treponema pallidum
B. Trichomoniasis – (ii) Trichomonas vaginalis
C. Genital herpes – (iii) Herpes Simplex Virus
D. Genital warts – (iv) Human Papillomavirus
1. A–i, B–ii, C–iii, D–iv
2. A–ii, B–i, C–iv, D–iii
3. A–iii, B–iv, C–i, D–ii
4. A–iv, B–iii, C–ii, D–i
Explanation: Syphilis is bacterial, Trichomoniasis is protozoan, Genital herpes and warts are viral. Correct answer: 1.

9. Fill in the Blanks MCQ:
_________ is a protozoan STI, and ________ is a bacterial STI.
1. Trichomoniasis, Syphilis
2. Syphilis, Trichomoniasis
3. Genital herpes, Syphilis
4. Hepatitis B, Genital warts
Explanation: Trichomoniasis is caused by Trichomonas vaginalis (protozoan) and Syphilis by Treponema pallidum (bacterial). Correct answer: 1.

10. Choose the Correct Statements MCQ:
Statement I: Syphilis is completely curable with penicillin.
Statement II: Genital herpes can be completely cured with antiviral drugs.
1. Both true
2. Both false
3. I true, II false
4. I false, II true
Explanation: Syphilis is curable with antibiotics; Genital herpes is incurable, managed with antivirals only. Correct answer: 3.

Topic: Disease Detection and Diagnostic Techniques; Subtopic: Molecular and Immunological Diagnostic Tools

Keyword Definitions:

• PCR (Polymerase Chain Reaction): A molecular technique used to amplify specific DNA sequences for detection of pathogens.

• ELISA (Enzyme Linked Immuno-Sorbent Assay): A biochemical test that identifies the presence of antigens or antibodies in a sample.

• Recombinant DNA Technology: A method used to manipulate genetic material for research or therapeutic purposes, not primarily for diagnosis.

• Serum Analysis: The study of blood serum to detect biochemical abnormalities or infections.

• Urine Analysis: A diagnostic test to check metabolic and kidney-related disorders.

Lead Question - 2023

Which one of the following techniques does not serve the purpose of early diagnosis of a disease for its early treatment?
(1) Polymerase Chain Reaction (PCR) technique
(2) Enzyme Linked Immuno-Sorbent Assay (ELISA) technique
(3) Recombinant DNA Technology
(4) Serum and Urine analysis

Answer & Explanation:
The correct answer is (3) Recombinant DNA Technology.
While PCR, ELISA, and biochemical analyses are used for early disease diagnosis, recombinant DNA technology is primarily used to create genetically modified organisms, produce therapeutic proteins like insulin, and study gene function. It is a research-based technique rather than a direct diagnostic tool for early disease detection in patients.

Guessed Question 1: Which technique amplifies specific DNA fragments for disease diagnosis?
(1) PCR
(2) ELISA
(3) Blotting
(4) Microarray
Answer & Explanation: (1) PCR. Polymerase Chain Reaction amplifies DNA, enabling detection of minute pathogen quantities. It identifies infectious diseases such as HIV and tuberculosis. PCR is highly sensitive and specific, making it an essential tool for early detection, genetic screening, and forensic investigations through rapid DNA replication cycles in laboratory diagnostics.

Guessed Question 2: ELISA is mainly used to detect:
(1) Antibody or antigen presence
(2) Genetic mutations
(3) Cell division rate
(4) Blood pressure levels
Answer & Explanation: (1) Antibody or antigen presence. ELISA works on antigen–antibody interaction principles. It is widely used in detecting HIV, hepatitis, and other infections. The enzyme-linked reaction produces a color change, indicating the presence of specific proteins. It combines immunological specificity with enzyme-based signal amplification for accurate clinical testing.

Guessed Question 3: Serum and urine analysis help detect abnormalities in:
(1) Liver and kidney function
(2) Bone development
(3) Nerve transmission
(4) Eye function
Answer & Explanation: (1) Liver and kidney function. Serum and urine analyses provide biochemical insights into organ function, glucose levels, electrolytes, and presence of toxins. They are simple, non-invasive diagnostic tools aiding early detection of metabolic, hepatic, or renal disorders, crucial for effective disease management and patient monitoring.

Guessed Question 4: Which of the following techniques is not based on antigen–antibody interaction?
(1) ELISA
(2) Western Blot
(3) PCR
(4) Immunofluorescence
Answer & Explanation: (3) PCR. Polymerase Chain Reaction relies on nucleic acid amplification, not antigen–antibody interaction. It detects DNA or RNA of pathogens. Immunoassays like ELISA and Western Blot depend on protein interactions, while PCR focuses on genetic material, making it a cornerstone of molecular diagnostics and genetic research applications.

Guessed Question 5: Recombinant DNA technology is primarily used for:
(1) Genetic modification and protein production
(2) Early disease diagnosis
(3) Urine testing
(4) Blood typing
Answer & Explanation: (1) Genetic modification and protein production. Recombinant DNA technology enables scientists to insert genes into host cells to express useful proteins like insulin, vaccines, or enzymes. It underpins biotechnology and therapeutic research but is not a direct diagnostic tool for detecting diseases in clinical practice settings.

Guessed Question 6: Which diagnostic technique can confirm HIV infection?
(1) PCR
(2) ELISA
(3) Both (1) and (2)
(4) None of these
Answer & Explanation: (3) Both (1) and (2). HIV diagnosis commonly involves ELISA as a preliminary screening method, followed by PCR for confirmation. ELISA detects antibodies, whereas PCR identifies viral RNA directly. Combining these techniques ensures high diagnostic accuracy and early intervention in viral infections through molecular and immunological approaches.

Guessed Question 7 (Assertion-Reason Type):
Assertion (A): PCR is a valuable tool for early detection of pathogens.
Reason (R): It amplifies specific DNA sequences, enabling detection even from minimal samples.
(1) Both A and R are true, and R explains A.
(2) Both A and R are true, but R does not explain A.
(3) A is true, R is false.
(4) Both A and R are false.
Answer & Explanation: (1) Both A and R are true, and R explains A. PCR detects infections in early stages by amplifying pathogen DNA millions of times, ensuring high sensitivity. It helps diagnose genetic and infectious diseases accurately before symptom onset, supporting rapid clinical decision-making and effective treatment strategies in healthcare.

Guessed Question 8 (Matching Type):
Match the following diagnostic tools with their applications:
A. PCR – (i) Detection of genetic diseases
B. ELISA – (ii) Detection of antigens
C. Western Blot – (iii) Confirmation of HIV
D. Urine analysis – (iv) Kidney function
(1) A-i, B-ii, C-iii, D-iv
(2) A-iv, B-i, C-ii, D-iii
(3) A-ii, B-iii, C-i, D-iv
(4) A-iii, B-ii, C-iv, D-i
Answer & Explanation: (1) A-i, B-ii, C-iii, D-iv. PCR identifies genetic abnormalities, ELISA detects antigen–antibody interactions, Western Blot confirms HIV diagnosis, and urine analysis monitors renal function. These diagnostic methods collectively contribute to modern medicine’s accuracy in identifying, confirming, and managing diseases efficiently across molecular and biochemical levels.

Guessed Question 9 (Fill in the Blanks):
ELISA works on the principle of _______ interaction.
(1) DNA–RNA
(2) Antigen–antibody
(3) Enzyme–substrate
(4) Hormone–receptor
Answer & Explanation: (2) Antigen–antibody. ELISA utilizes specific antigen–antibody binding to identify infectious agents or immune responses. The enzyme linked to the antibody produces a measurable color change when substrate is added, enabling quantitative analysis of antigen presence, widely applied in clinical diagnosis and immunological testing procedures.

Guessed Question 10 (Choose the Correct Statements):
Statement I: Recombinant DNA technology helps in producing human insulin.
Statement II: It is mainly used as a disease diagnostic method.
(1) Statement I true, Statement II false.
(2) Statement I false, Statement II true.
(3) Both statements true.
(4) Both statements false.
Answer & Explanation: (1) Statement I true, Statement II false. Recombinant DNA technology enables the synthesis of human insulin, vaccines, and enzymes through gene manipulation. However, it is not designed for direct diagnosis but for therapeutic and research applications, distinguishing it from molecular and immunological diagnostic tools.

Topic: Drugs and Alcohol Abuse; Subtopic: Effects of Drugs on the Nervous System

Keyword Definitions:

• Heroin: A depressant drug derived from morphine that slows down body functions and causes addiction.

• Marijuana: A hallucinogenic drug obtained from Cannabis that affects perception and coordination.

• Cocaine: A powerful stimulant that interferes with dopamine transport and causes euphoria and addiction.

• Morphine: A strong painkiller derived from opium used in medicine to relieve severe pain.

• Depressants: Drugs that reduce the activity of the central nervous system, leading to relaxation and drowsiness.

• Hallucinogens: Substances that alter perception, mood, and sensory experiences.

• Stimulants: Drugs that increase alertness, heart rate, and energy levels by stimulating the nervous system.

• Addiction: A chronic disorder characterized by compulsive drug-seeking behavior despite harmful consequences.

• Dopamine: A neurotransmitter involved in pleasure and reward pathways in the brain.

• Withdrawal symptoms: Physical and psychological effects that occur when a dependent person stops using a drug.

• Drug abuse: Excessive or inappropriate use of chemical substances leading to health and social problems.

Lead Question - 2023:

Match List I with List II.
List I    List II
A. Heroin    I. Effect on cardiovascular system
B. Marijuana    II. Slow down body function
C. Cocaine    III. Painkiller
D. Morphine    IV. Interfere with transport of dopamine

Choose the correct answer from the options given below:
(1) A-IV, B-III, C-II, D-I
(2) A-III, B-IV, C-I, D-II
(3) A-II, B-I, C-IV, D-III
(4) A-I, B-II, C-III, D-IV

Answer & Explanation: (3) A-II, B-I, C-IV, D-III. Heroin is a depressant that slows down body functions. Marijuana affects the cardiovascular system and perception. Cocaine interferes with dopamine transport, causing overstimulation of pleasure centers. Morphine is a strong analgesic or painkiller. These drugs show varied effects on the nervous system and lead to addiction if misused over time.

1. Which of the following is a depressant drug?
(1) Cocaine
(2) Heroin
(3) LSD
(4) Amphetamine
Explanation: Heroin is a depressant derived from morphine that slows body metabolism and induces sleep and drowsiness. Correct answer is (2). It depresses the central nervous system and leads to severe physical and psychological dependence. Long-term use results in tolerance, addiction, and withdrawal symptoms upon discontinuation.

2. The addictive property of cocaine is due to its interference with:
(1) Serotonin
(2) Dopamine transport
(3) Acetylcholine
(4) Norepinephrine
Explanation: Cocaine blocks the reuptake of dopamine in synapses, leading to prolonged stimulation of pleasure centers. Correct answer is (2). This causes euphoria and psychological dependence. The sudden withdrawal results in depression and fatigue, highlighting cocaine’s severe neurochemical impact on mood regulation.

3. Marijuana is obtained from which plant?
(1) Erythroxylum coca
(2) Cannabis sativa
(3) Papaver somniferum
(4) Nicotiana tabacum
Explanation: Marijuana is extracted from dried flowers and leaves of Cannabis sativa. Correct answer is (2). It contains tetrahydrocannabinol (THC), which causes relaxation and altered perception. Prolonged use affects coordination, reaction time, and cardiovascular function, making it a hallucinogenic and partially depressant drug.

4. Which of the following is a natural opiate?
(1) Morphine
(2) LSD
(3) Cocaine
(4) Marijuana
Explanation: Morphine is a natural opiate derived from the opium poppy, Papaver somniferum. Correct answer is (1). It acts as an analgesic by binding to opioid receptors in the brain and spinal cord, reducing pain sensation. However, excessive use leads to tolerance and dependence in chronic patients.

5. Which of the following statements about drug abuse is incorrect?
(1) It causes physical and mental dependence
(2) It improves brain function permanently
(3) It alters perception and mood
(4) It can damage the nervous system
Explanation: Drugs never improve brain function permanently; instead, they disrupt normal brain activity. Correct answer is (2). Prolonged usage leads to cognitive decline, mood instability, and health deterioration, affecting both physical and psychological well-being of individuals addicted to such substances.

6. Which neurotransmitter is mainly affected by heroin?
(1) Acetylcholine
(2) Dopamine
(3) Endorphins
(4) Serotonin
Explanation: Heroin mimics endorphins, the body’s natural pain-relieving neurotransmitters, binding to opioid receptors in the brain. Correct answer is (3). It produces euphoria, sedation, and dependence. Chronic use alters normal endorphin balance, resulting in tolerance and withdrawal symptoms when the drug is stopped abruptly.

Assertion-Reason Question
7. Assertion (A): Cocaine stimulates the central nervous system and increases alertness.
Reason (R): It blocks dopamine reuptake in synaptic clefts, prolonging its effect.
(1) Both A and R true, and R explains A
(2) Both A and R true, but R does not explain A
(3) A true, R false
(4) A false, R true
Explanation: Both statements are true and R correctly explains A. Cocaine inhibits dopamine reuptake, resulting in overstimulation of the pleasure centers. Correct answer is (1). This causes heightened alertness and euphoria initially but leads to addiction and severe withdrawal symptoms with prolonged use.

Matching Type Question
8. Match the drug with its major effect:
A. Alcohol – i. Hallucinogenic effect
B. LSD – ii. Depressant
C. Nicotine – iii. Stimulant
D. Morphine – iv. Painkiller
(1) A-ii, B-i, C-iii, D-iv
(2) A-i, B-ii, C-iv, D-iii
(3) A-iv, B-iii, C-ii, D-i
(4) A-iii, B-iv, C-i, D-ii
Explanation: Alcohol is a depressant, LSD a hallucinogen, nicotine a stimulant, and morphine a painkiller. Correct answer is (1). These drugs differ in chemical nature and physiological effects, influencing mood, perception, and body function through their action on the nervous system.

Fill in the Blanks Question
9. LSD acts as a _______ drug that causes hallucinations and altered sensory perception.
(1) Depressant
(2) Hallucinogenic
(3) Stimulant
(4) Analgesic
Explanation: LSD (Lysergic acid diethylamide) is a hallucinogenic drug that alters sensory perception and induces vivid visual illusions. Correct answer is (2). It affects serotonin receptors in the brain, leading to extreme mood swings and psychological disturbances in chronic users or after high doses.

Choose the Correct Statements Question
10. Statement I: Morphine acts on opioid receptors to relieve pain.
Statement II: Cocaine acts as a depressant on the nervous system.
(1) Both I and II true
(2) Only I true
(3) Only II true
(4) Both false
Explanation: Morphine binds to opioid receptors and provides analgesia, making Statement I true. Cocaine, however, is a stimulant, not a depressant, making Statement II false. Correct answer is (2). Thus, these drugs show contrasting actions on the nervous system—one slows it down while the other excites it.

Topic: Infectious Diseases; Subtopic: Pathogens and Disease Causation

Keyword Definitions:

• Ringworm: Superficial fungal infection of skin, hair, or nails caused by dermatophytes such as Trichophyton species.

• Filariasis: Parasitic disease caused by nematode worms like Wuchereria bancrofti, transmitted by mosquitoes, leading to lymphatic obstruction.

• Malaria: Vector-borne infectious disease caused by Plasmodium species, transmitted by Anopheles mosquitoes, characterized by periodic fever and chills.

• Pneumonia: Inflammatory condition of lungs, often caused by bacteria such as Haemophilus influenzae, leading to fluid accumulation and impaired gas exchange.

• Trichophyton: Genus of fungi causing superficial infections like ringworm and athlete’s foot.

• Wuchereria bancrofti: Filariid nematode worm responsible for lymphatic filariasis in humans.

• Plasmodium vivax: Protozoan parasite causing relapsing malaria, prevalent in tropical and subtropical regions.

• Haemophilus influenzae: Gram-negative bacterium causing respiratory infections including pneumonia and meningitis.

• Pathogen: Microorganism capable of causing disease in host organisms.

• Vector: Organism, often an insect, that transmits pathogens from one host to another.

• Infectious disease: Disease caused by pathogenic microorganisms, transmissible between hosts.

Lead Question - 2023:

Match List I with List II.
List I   List II
A. Ringworm  I. Haemophilus influenzae
B. Filariasis  II. Trichophyton
C. Malaria  III. Wuchereria bancrofti
D. Pneumonia  IV. Plasmodium vivax
Choose the correct answer from the options given below:
(1) A-III, B-II, C-I, D-IV
(2) A-III, B-II, C-IV, D-I
(3) A-II, B-III, C-IV, D-I
(4) A-II, B-III, C-I, D-IV

Answer & Explanation: (3) A-II, B-III, C-IV, D-I. Ringworm is caused by the fungus Trichophyton, making A-II correct. Filariasis is a parasitic disease caused by Wuchereria bancrofti, so B-III is correct. Malaria is caused by the protozoan Plasmodium vivax, therefore C-IV is correct. Pneumonia can be caused by the bacterium Haemophilus influenzae, making D-I correct. Understanding the correct pathogen-disease association is crucial for diagnosis and treatment. This mapping highlights fungal, parasitic, protozoan, and bacterial infections affecting humans, emphasizing the diversity of infectious agents and the importance of identifying the causative organism accurately for effective management.

1. Ringworm is caused by:
(1) Plasmodium vivax
(2) Trichophyton
(3) Wuchereria bancrofti
(4) Haemophilus influenzae
Explanation: Ringworm is a superficial fungal infection caused by dermatophytes such as Trichophyton species. These fungi invade keratinized tissues like skin, hair, and nails. Proper identification of the causative fungus is essential for antifungal treatment. Correct answer is (2).

2. Filariasis is transmitted by:
(1) Anopheles mosquito
(2) Aedes mosquito
(3) Culex mosquito
(4) Tsetse fly
Explanation: Filariasis is caused by Wuchereria bancrofti, transmitted by Culex mosquitoes. Larvae enter the human lymphatic system, causing blockage and edema. Correct answer is (3).

3. Malaria is caused by:
(1) Wuchereria bancrofti
(2) Trichophyton
(3) Plasmodium vivax
(4) Haemophilus influenzae
Explanation: Malaria is caused by the protozoan parasite Plasmodium vivax, transmitted through Anopheles mosquitoes, leading to periodic fever and chills. Correct answer is (3).

4. Pneumonia can be caused by:
(1) Trichophyton
(2) Haemophilus influenzae
(3) Plasmodium vivax
(4) Wuchereria bancrofti
Explanation: Pneumonia, an inflammatory lung condition, can be caused by Haemophilus influenzae, resulting in fluid accumulation in alveoli and impaired respiration. Correct answer is (2).

5. The causative agent of lymphatic obstruction in filariasis is:
(1) Plasmodium vivax
(2) Haemophilus influenzae
(3) Wuchereria bancrofti
(4) Trichophyton
Explanation: Wuchereria bancrofti is a filarial nematode that infects the lymphatic system, causing obstruction, edema, and elephantiasis. Correct answer is (3).

6. Which pathogen causes relapsing fever and cyclical chills?
(1) Trichophyton
(2) Plasmodium vivax
(3) Wuchereria bancrofti
(4) Haemophilus influenzae
Explanation: Plasmodium vivax causes malaria characterized by relapsing fever, chills, and anemia due to repeated erythrocytic cycles. Correct answer is (2).

Assertion-Reason Question
7. Assertion (A): Filariasis leads to lymphatic blockage.
Reason (R): Wuchereria bancrofti larvae mature in human lymphatic vessels.
(1) Both A and R true, R explains A
(2) Both A and R true, R does not explain A
(3) A true, R false
(4) A false, R true
Explanation: Wuchereria bancrofti larvae develop in human lymphatics, causing obstruction and edema, making both statements true. R correctly explains A. Correct answer is (1).

Matching Type Question
8. Match disease with pathogen:
A. Ringworm – i. Trichophyton
B. Pneumonia – ii. Haemophilus influenzae
C. Malaria – iii. Plasmodium vivax
D. Filariasis – iv. Wuchereria bancrofti
(1) A-i, B-ii, C-iii, D-iv
(2) A-ii, B-i, C-iv, D-iii
(3) A-iii, B-iv, C-i, D-ii
(4) A-iv, B-iii, C-ii, D-i
Explanation: Correct matching: Ringworm-Trichophyton, Pneumonia-Haemophilus influenzae, Malaria-Plasmodium vivax, Filariasis-Wuchereria bancrofti. Correct answer is (1).

Fill in the Blanks Question
9. The protozoan responsible for malaria in humans is ________.
(1) Wuchereria bancrofti
(2) Plasmodium vivax
(3) Trichophyton
(4) Haemophilus influenzae
Explanation: Plasmodium vivax is the protozoan parasite causing malaria, transmitted by Anopheles mosquitoes. Correct answer is (2).

Choose the Correct Statements Question
10. Statement I: Ringworm is caused by a fungus.
Statement II: Pneumonia can be caused by a bacterium.
(1) Only Statement I correct
(2) Only Statement II correct
(3) Both I and II correct
(4) Both I and II incorrect
Explanation: Ringworm is caused by dermatophyte fungi, and pneumonia can be caused by bacteria such as Haemophilus influenzae. Both statements are correct. Correct answer is (3).

Topic: HIV Infection and Replication; Subtopic: Target Cells of HIV

Keyword Definitions:

• HIV (Human Immunodeficiency Virus): A retrovirus that infects the immune system, particularly CD4+ T-helper cells, leading to immunodeficiency.

• TH cells: CD4+ T-helper lymphocytes that play a central role in activating immune responses by stimulating B cells and cytotoxic T cells.

• B-lymphocytes: White blood cells responsible for humoral immunity, producing antibodies against pathogens.

• Basophils: Granulocytes involved in inflammatory responses and release of histamine and heparin.

• Eosinophils: Granulocytes that combat parasitic infections and modulate allergic reactions.

• Replication: Process by which viruses produce progeny by hijacking the host cell machinery.

• Progeny viruses: Newly formed virus particles generated inside an infected host cell.

• Immune system: Network of cells and molecules that protect the body from infections.

• CD4 receptor: Surface protein on T-helper cells recognized by HIV for entry.

• Retrovirus: Virus with RNA genome that reverse transcribes its RNA into DNA in the host cell.

• Viremia: Presence of viruses in the blood, often associated with infection severity.

Lead Question - 2023:

In which blood corpuscles does HIV undergo replication and produce progeny viruses?
(1) Basophils
(2) Eosinophils
(3) TH cells
(4) B-lymphocytes

Answer & Explanation: (3) TH cells. HIV specifically targets CD4+ T-helper (TH) cells due to the presence of CD4 receptors, allowing viral entry. Once inside, the viral RNA is reverse transcribed into DNA, integrated into the host genome, and directs synthesis of viral proteins to assemble progeny viruses. Basophils and eosinophils are not infected by HIV, and B-lymphocytes lack CD4 receptors, although they are indirectly affected due to impaired TH cell-mediated activation. The destruction of TH cells compromises cellular and humoral immunity, leading to immunodeficiency and opportunistic infections. Viral replication in TH cells is central to the progression of HIV infection.

1. Which receptor on TH cells allows HIV entry?
(1) CD8
(2) CD4
(3) CCR5 only
(4) CXCR4 only
Explanation: CD4 receptor on T-helper cells is recognized by HIV for attachment, with co-receptors CCR5 or CXCR4 facilitating viral entry. Correct answer is (2).

2. HIV is classified as a:
(1) DNA virus
(2) Retrovirus
(3) Bacteriophage
(4) RNA virus without reverse transcription
Explanation: HIV is a retrovirus with RNA genome that reverse transcribes its RNA into DNA in host cells. Correct answer is (2).

3. The main effect of HIV on TH cells is:
(1) Increased proliferation
(2) Cell death and depletion
(3) Transformation into B cells
(4) Phagocytosis
Explanation: HIV infection leads to destruction and depletion of TH cells, weakening both cellular and humoral immunity. Correct answer is (2).

4. Which blood cells produce antibodies?
(1) TH cells
(2) B-lymphocytes
(3) Basophils
(4) Eosinophils
Explanation: B-lymphocytes are responsible for humoral immunity, producing antibodies against pathogens. Correct answer is (2).

5. Viremia refers to:
(1) Virus replication inside cells
(2) Presence of viruses in blood
(3) Antibody production
(4) Immune activation
Explanation: Viremia is the presence of viruses in the bloodstream, often associated with the severity of infection. Correct answer is (2).

6. Co-receptors assisting HIV entry include:
(1) CD8 and MHC I
(2) CCR5 and CXCR4
(3) TLR4 and CD3
(4) IgG and IgM
Explanation: CCR5 and CXCR4 act as co-receptors for HIV entry into CD4+ TH cells. Correct answer is (2).

Assertion-Reason Question
7. Assertion (A): HIV replication occurs in TH cells.
Reason (R): TH cells express CD4 receptors facilitating viral entry.
(1) Both A and R true, R explains A
(2) Both A and R true, R does not explain A
(3) A true, R false
(4) A false, R true
Explanation: TH cells are the primary site for HIV replication because they express CD4 receptors required for viral entry. Both A and R are true, and R correctly explains A. Correct answer is (1).

Matching Type Question
8. Match the virus with its target cells:
A. HIV – i. CD4+ TH cells
B. Influenza virus – ii. Respiratory epithelial cells
C. Hepatitis B virus – iii. Hepatocytes
D. Rabies virus – iv. Neurons
(1) A-i, B-ii, C-iii, D-iv
(2) A-ii, B-i, C-iv, D-iii
(3) A-iv, B-iii, C-ii, D-i
(4) A-iii, B-iv, C-i, D-ii
Explanation: HIV targets CD4+ TH cells, Influenza virus infects respiratory epithelial cells, Hepatitis B virus infects hepatocytes, and Rabies virus infects neurons. Correct answer is (1).

Fill in the Blanks Question
9. The enzyme used by HIV to convert RNA into DNA is ________.
(1) DNA polymerase
(2) Reverse transcriptase
(3) Integrase
(4) Protease
Explanation: HIV uses reverse transcriptase to synthesize DNA from its RNA genome inside host TH cells. Correct answer is (2).

Choose the Correct Statements Question
10. Statement I: HIV directly infects CD4+ T-helper cells.
Statement II: B-lymphocytes are the main site for HIV replication.
(1) Only Statement I is correct
(2) Only Statement II is correct
(3) Both I and II are correct
(4) Both I and II are incorrect
Explanation: HIV specifically infects CD4+ TH cells; B-lymphocytes are not the main site for replication. Statement I is correct, Statement II is incorrect. Correct answer is (1).

Chapter : Immunology; Topic : Body Defenses; Subtopic : Barriers and Immune Response

Keyword Definitions :

• Cellular Barrier : Defense provided by immune cells like neutrophils and macrophages that destroy pathogens.

• Cytokine Barrier : Molecules such as interferons and interleukins that regulate immune response and inhibit pathogen replication.

• Physical Barrier : Structural defenses like skin and mucus that prevent entry of pathogens into the body.

• Physiological Barrier : Chemical conditions, e.g., gastric HCl or enzymes, that inhibit pathogen growth.

• Neutrophils : White blood cells involved in phagocytosis of pathogens.

• Interferons : Proteins secreted by cells to interfere with viral replication.

• Mucus : Sticky secretion lining respiratory and digestive tracts to trap pathogens.

• HCl : Hydrochloric acid in the stomach that destroys ingested microbes.

• Immune System : Network of cells, tissues, and molecules defending against infections.

• Innate Immunity : Non-specific defense present from birth, includes barriers and phagocytic cells.

Lead Question - 2022 (Ganganagar)
Match List-I with List-II:
List-I      List-II
(a) Cellular barrier      (i) Interferons
(b) Cytokine barrier      (ii) Mucus
(c) Physical barrier      (iii) Neutrophils
(d) Physiological barrier      (iv) HCl in gastric juice
Choose the correct answer from the options given below:
1. (ii) (iii) (iv) (i)
2. (ii) (iii) (i) (iv)
3. (iii) (iv) (ii) (i)
4. (iii) (i) (ii) (iv)

Explanation : Cellular barriers include immune cells such as neutrophils that phagocytose pathogens, matching (a)-(iii). Cytokine barriers include signaling molecules like interferons that prevent viral replication, matching (b)-(i). Physical barriers like mucus trap pathogens, matching (c)-(ii). Physiological barriers include chemical defenses like HCl in gastric juice, matching (d)-(iv). Therefore, the correct option is Option 4.

1. Single Correct Answer:
Which of the following cells are part of the cellular barrier?
1. Red blood cells
2. Neutrophils
3. Platelets
4. Endothelial cells

Explanation : Neutrophils are white blood cells that act as a cellular barrier by phagocytosing and destroying pathogens. Red blood cells transport oxygen, platelets aid in clotting, and endothelial cells line blood vessels but do not directly defend against pathogens. Hence, Option 2 is correct.

2. Single Correct Answer:
Interferons primarily belong to which barrier type?
1. Physical barrier
2. Cytokine barrier
3. Cellular barrier
4. Physiological barrier

Explanation : Interferons are signaling proteins released by infected cells to prevent viral replication and modulate immune response, classifying them as a cytokine barrier. They do not form structural, cellular, or chemical defenses. Hence, Option 2 is correct.

3. Single Correct Answer:
Which is an example of a physical barrier?
1. HCl
2. Mucus
3. Neutrophils
4. Interferons

Explanation : Mucus is a physical barrier that traps pathogens in the respiratory and digestive tracts, preventing entry into tissues. HCl is a physiological barrier, neutrophils are cellular, and interferons are cytokines. Hence, Option 2 is correct.

4. Single Correct Answer:
Which substance represents a physiological barrier?
1. Interferons
2. HCl in gastric juice
3. Mucus
4. Macrophages

Explanation : Physiological barriers include chemical defenses like hydrochloric acid in gastric juice that destroy ingested microbes. Interferons are cytokines, mucus is a physical barrier, and macrophages are cellular barriers. Hence, Option 2 is correct.

5. Single Correct Answer:
Neutrophils primarily provide defense through:
1. Chemical secretion
2. Phagocytosis
3. Physical blocking
4. Hormone production

Explanation : Neutrophils act as a cellular barrier by engulfing and destroying pathogens through phagocytosis. Chemical secretion and hormone production are functions of other cells, and physical blocking is performed by structures like mucus or skin. Hence, Option 2 is correct.

6. Single Correct Answer:
Which barrier prevents viral replication inside cells?
1. Physical barrier
2. Cytokine barrier
3. Cellular barrier
4. Physiological barrier

Explanation : Cytokines like interferons prevent viral replication within cells and modulate immune response, acting as a cytokine barrier. Physical barriers block entry, cellular barriers destroy pathogens, and physiological barriers include chemical defenses. Hence, Option 2 is correct.

7. Assertion-Reason:
Assertion (A): Mucus acts as a physical barrier.
Reason (R): It traps and prevents pathogen entry into tissues.
1. Both A and R are true, and R is the correct explanation of A
2. Both A and R are true, but R is not the correct explanation of A
3. A is true, R is false
4. A is false, R is true

Explanation : Mucus acts as a physical barrier because it traps pathogens and prevents them from entering epithelial tissues, directly explaining its defensive role. Hence, both assertion and reason are correct, and the reason explains the assertion. Therefore, Option 1 is correct.

8. Matching Type:
Match List-I with List-II:
List-I      List-II
(a) Cellular barrier      (i) Neutrophils
(b) Cytokine barrier      (ii) Interferons
(c) Physical barrier      (iii) Mucus
(d) Physiological barrier      (iv) HCl in gastric juice
1. (a)-(i), (b)-(ii), (c)-(iii), (d)-(iv)
2. (a)-(ii), (b)-(i), (c)-(iv), (d)-(iii)
3. (a)-(iii), (b)-(iv), (c)-(i), (d)-(ii)
4. (a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)

Explanation : Cellular barriers involve neutrophils (a-i), cytokines like interferons form the cytokine barrier (b-ii), physical barriers include mucus (c-iii), and physiological barriers include HCl (d-iv). Correct matching is (a)-(i), (b)-(ii), (c)-(iii), (d)-(iv). Hence, Option 1 is correct.

9. Fill in the Blank:
The first line of defense against pathogens includes _______.
1. Cytokines
2. Immune cells
3. Physical and physiological barriers
4. Antibodies

Explanation : Physical barriers like skin and mucus, along with physiological barriers like gastric HCl, form the first line of defense by preventing pathogen entry. Cytokines, immune cells, and antibodies are part of secondary or specific defense mechanisms. Hence, Option 3 is correct.

10. Choose the correct statements:
Statement I: Interferons are part of the cytokine barrier.
Statement II: HCl in gastric juice is a cellular barrier.
1. Both statements are correct
2. Only Statement I is correct
3. Only Statement II is correct
4. Both statements are incorrect

Explanation : Interferons are cytokines, forming the cytokine barrier (Statement I correct). HCl in gastric juice is a physiological, not cellular, barrier (Statement II incorrect). Hence, the correct answer is Option 2.

Chapter: Immunology and Human Health; Topic: Transplantation and Graft Rejection; Subtopic: Mechanisms of Immune Response in Organ Transplantation

Keyword Definitions:

• Graft: Tissue or organ transplanted from a donor to a recipient.

• Graft Rejection: Immune response of recipient against transplanted tissue leading to its destruction.

• Recipient: Individual receiving the transplanted organ or tissue.

• Self and Non–self Recognition: Ability of immune system to distinguish between body's own cells and foreign cells.

• Humoral Immune Response: Immune response mediated by antibodies produced by B lymphocytes.

• Cell-mediated Response: Immune response mediated by T lymphocytes without antibodies.

• Auto-immune Response: Immune system attacking its own healthy cells.

• Organ Transplantation: Surgical transfer of an organ from one individual to another.

• Major Histocompatibility Complex (MHC): Set of proteins on cell surface that presents antigens to immune system.

• Allograft: Graft between genetically different individuals of same species.

• Rejection: Failure of the graft due to immune attack.

Lead Question - 2022 (Ganganagar)

Which of the following reasons is mainly responsible for graft rejection in transplantation of organs?

1. Inability of recipient to differentiate between 'self' and 'non–self' tissues/cells

2. Humoral immune response only

3. Auto–immune response

4. Cell–mediated response

Explanation: Graft rejection occurs primarily because the recipient's immune system recognizes the transplanted organ as 'non–self'. This is mainly due to cell-mediated immune responses involving T lymphocytes attacking foreign MHC molecules on donor tissues. Humoral immunity plays a secondary role, while auto-immune responses are unrelated. The inability to recognize self versus non–self is a fundamental reason, making option 1 correct. Cell-mediated immunity is the direct effector in rejection, but it occurs because of non–self recognition. Therefore, the main reason for graft rejection is the immune system detecting non–self cells.

1. Single Correct Answer MCQ:

Which cells are primarily responsible for cell-mediated graft rejection?

a) B lymphocytes

b) T lymphocytes

c) Macrophages only

d) Plasma cells

Explanation: T lymphocytes are central in mediating graft rejection by recognizing non–self antigens and destroying donor cells. B cells contribute antibodies but are not the primary effectors. Correct answer is b.

2. Single Correct Answer MCQ:

An allograft refers to:

a) Graft from same individual

b) Graft from genetically different individual of same species

c) Graft from a different species

d) Synthetic graft

Explanation: Allografts are transplants between genetically non-identical members of the same species, often leading to immune-mediated rejection. Correct answer is b.

3. Single Correct Answer MCQ:

Major histocompatibility complex (MHC) molecules are important in graft rejection because:

a) They produce antibodies

b) They present antigens to T cells

c) They digest donor cells

d) They inactivate immune response

Explanation: MHC molecules present donor antigens to recipient T cells, triggering cell-mediated immune response and graft rejection. Correct answer is b.

4. Single Correct Answer MCQ:

Which type of immune response is secondary in graft rejection?

a) Humoral response

b) Cell-mediated response

c) Auto-immune response

d) Innate immunity

Explanation: Humoral immune response involving antibodies contributes but is secondary to T-cell mediated graft rejection. Correct answer is a.

5. Single Correct Answer MCQ:

Failure of graft due to recipient's immune attack is called:

a) Autoimmunity

b) Graft acceptance

c) Graft rejection

d) Immunodeficiency

Explanation: Graft rejection is the immune-mediated destruction of transplanted tissue recognized as non–self. Correct answer is c.

6. Single Correct Answer MCQ:

Which of the following can reduce graft rejection?

a) Immunosuppressive drugs

b) High-protein diet

c) Exercise

d) Antibiotics

Explanation: Immunosuppressive drugs reduce T-cell activity and help prevent graft rejection. Correct answer is a.

7. Assertion-Reason MCQ:

Assertion (A): Cell-mediated immunity is the major cause of graft rejection.

Reason (R): T lymphocytes recognize donor MHC molecules and attack.

a) Both A and R true, R explains A

b) Both A and R true, R does not explain A

c) A true, R false

d) Both false

Explanation: Both A and R are true, and R correctly explains why cell-mediated immunity causes graft rejection. Correct answer is a.

8. Matching Type MCQ:

Match List-I with List-II:

List-I | List-II

(a) Allograft | (i) Different species

(b) Autograft | (ii) Same individual

(c) Xenograft | (iii) Genetically different same species

(d) Isograft | (iv) Genetically identical individual

Options:

1. a-iii, b-ii, c-i, d-iv

2. a-ii, b-iii, c-i, d-iv

3. a-i, b-ii, c-iii, d-iv

4. a-iii, b-iv, c-i, d-ii

Explanation: Correct matches are: Allograft (iii), Autograft (ii), Xenograft (i), Isograft (iv). Correct answer is 1.

9. Fill in the Blanks / Completion MCQ:

Primary immune mechanism in graft rejection is _______.

a) Humoral immunity

b) Cell-mediated immunity

c) Autoimmune attack

d) Innate immunity

Explanation: T-cell mediated (cell-mediated) immunity is the main mechanism leading to graft rejection by attacking donor cells. Correct answer is b.

10. Choose the correct statements MCQ (Statement I & II):

Statement I: Graft rejection occurs when recipient immune system recognizes transplanted tissue as non–self.

Statement II: Autoimmune responses are the main cause of graft rejection.

a) Both I and II correct

b) Only I correct

c) Only II correct

d) Both incorrect

Explanation: Statement I is correct; Statement II is incorrect because autoimmunity attacks self cells, not donor grafts. Correct answer is b. 

Topic: Immunology and Transplantation; Subtopic: Immuno-suppressants and Immune Response Regulation

Keyword Definitions:

• Immuno-suppressants: Drugs that reduce the strength of the body’s immune system to prevent rejection of transplanted organs or reduce inflammation.

• Cell-mediated immunity: Immune response involving T lymphocytes that destroy infected or foreign cells.

• Humoral immunity: Immune response mediated by antibodies produced by B lymphocytes.

• Cytokine storm: Excessive immune response caused by overproduction of cytokines leading to tissue damage.

• Innate immunity: The body’s natural, non-specific defense mechanism present from birth.

Lead Question – 2022 (Abroad)
Immuno-suppressants are administered to burn-patients or during organ transplantation to suppress:
1. Innate immunity
2. Cytokine storm
3. Humoral immunity
4. Cell-mediated immunity

Explanation: During organ transplantation, immuno-suppressants are used to suppress cell-mediated immunity to prevent the rejection of the transplanted organ. T lymphocytes recognize the transplanted tissue as foreign and trigger immune destruction. Immuno-suppressants like cyclosporine inhibit this reaction while allowing partial humoral immunity to function. Correct answer: 4. Cell-mediated immunity

1. Which cells are primarily suppressed by immuno-suppressive drugs during organ transplantation?
1. B-lymphocytes
2. T-lymphocytes
3. Natural killer cells
4. Macrophages

Explanation: Immuno-suppressive drugs mainly act on T-lymphocytes, which are responsible for recognizing and attacking foreign antigens such as transplanted organs. By suppressing T-cell activation, rejection is minimized, allowing graft survival while maintaining some immune defense. Correct answer: 2. T-lymphocytes

2. Which of the following is a commonly used immuno-suppressive drug in organ transplantation?
1. Penicillin
2. Cyclosporine
3. Insulin
4. Paracetamol

Explanation: Cyclosporine is a potent immuno-suppressant used to prevent organ rejection after transplantation. It inhibits activation of T-cells by blocking interleukin-2 synthesis. Other drugs like azathioprine and tacrolimus are also used for similar purposes. Correct answer: 2. Cyclosporine

3. Which organ is commonly transplanted and requires long-term immuno-suppressive therapy?
1. Liver
2. Heart
3. Kidney
4. Lungs

Explanation: Kidney transplantation is the most common organ transplant worldwide. Recipients require lifelong immuno-suppressive medication to prevent rejection and maintain graft function. Drugs like cyclosporine and prednisolone are commonly prescribed. Correct answer: 3. Kidney

4. Which type of immunity is mainly responsible for graft rejection?
1. Innate immunity
2. Passive immunity
3. Cell-mediated immunity
4. Artificial immunity

Explanation: Cell-mediated immunity, driven by cytotoxic T-cells, is responsible for graft rejection. These T-cells recognize antigens on donor tissue as foreign and destroy the graft cells through immune attack. Immuno-suppressive drugs prevent this mechanism. Correct answer: 3. Cell-mediated immunity

5. Which of the following organs is least likely to cause rejection after transplantation?
1. Heart
2. Kidney
3. Liver
4. Lungs

Explanation: The liver is less immunogenic and more tolerant than other organs, hence it has lower chances of rejection after transplantation. This is due to its unique immune-regulating properties and regenerative capacity. Correct answer: 3. Liver

6. Which of the following immuno-suppressive drugs acts by inhibiting DNA synthesis in lymphocytes?
1. Azathioprine
2. Cyclosporine
3. Tacrolimus
4. Prednisolone

Explanation: Azathioprine is an immuno-suppressant that inhibits DNA synthesis in proliferating lymphocytes, reducing both humoral and cell-mediated immune responses. It is often used in combination with cyclosporine for effective suppression. Correct answer: 1. Azathioprine

Assertion-Reason Question
7. Assertion (A): Cyclosporine prevents transplant rejection by suppressing T-cell activation.
Reason (R): It blocks interleukin-2 production necessary for T-cell proliferation.
1. Both (A) and (R) are true and (R) is the correct explanation of (A)
2. Both (A) and (R) are true but (R) is not the correct explanation of (A)
3. (A) is true but (R) is false
4. (A) is false but (R) is true

Explanation: Cyclosporine suppresses T-cell activation by blocking calcineurin and thereby inhibiting interleukin-2 (IL-2) synthesis, which is essential for T-cell proliferation. Thus, both statements are true, and (R) correctly explains (A). Correct answer: 1. Both (A) and (R) are true and (R) is the correct explanation of (A)

Matching Type Question
8. Match the following drugs with their functions:
A. Cyclosporine — (i) Inhibits IL-2 synthesis
B. Azathioprine — (ii) Blocks DNA replication
C. Prednisolone — (iii) Reduces inflammation
D. Tacrolimus — (iv) Calcineurin inhibitor
1. A–i, B–ii, C–iii, D–iv
2. A–ii, B–iv, C–i, D–iii
3. A–iv, B–i, C–ii, D–iii
4. A–iii, B–ii, C–i, D–iv

Explanation: Cyclosporine inhibits IL-2 synthesis (i). Azathioprine blocks DNA replication (ii). Prednisolone reduces inflammation (iii). Tacrolimus acts as a calcineurin inhibitor (iv), similar in function to cyclosporine but more potent. Correct answer: 1. A–i, B–ii, C–iii, D–iv

Fill in the Blanks Question
9. The drug ________ is used to suppress immune response in transplant patients by inhibiting interleukin-2 synthesis.
1. Prednisolone
2. Azathioprine
3. Cyclosporine
4. Tacrolimus

Explanation: Cyclosporine inhibits calcineurin, which is essential for interleukin-2 synthesis. IL-2 is a key cytokine required for T-cell activation and proliferation. By blocking its production, cyclosporine effectively prevents transplant rejection. Correct answer: 3. Cyclosporine

Choose the Correct Statements Question
10. Statement I: Immuno-suppressants completely destroy the immune system.
Statement II: They are used in limited doses to prevent graft rejection while maintaining basic immunity.
1. Only Statement I is correct
2. Only Statement II is correct
3. Both Statements are correct
4. Both Statements are incorrect

Explanation: Immuno-suppressants do not completely destroy the immune system but selectively suppress certain immune responses to prevent rejection. They are administered in controlled doses to maintain partial immunity for protection against infections. Correct answer: 2. Only Statement II is correct

Chapter: Immunology
Topic: Acquired Immunity
Subtopic: Primary and Secondary Immune Response

Keyword Definitions:

• Acquired immunity: Adaptive immune system developed after exposure to specific pathogens.

• Anamnestic response: Enhanced secondary immune response upon re-exposure to the same pathogen.

• Memory cells: Long-lived lymphocytes that remember previous pathogen exposure to produce faster and stronger response.

• Primary response: Initial immune response triggered by first encounter with a pathogen, usually slower and weaker.

• Specific defense: Immune mechanisms targeting specific antigens.

• Non-specific defense: Innate immunity present from birth, including barriers and phagocytic cells.

• Pathogen: Microorganism causing disease in host organism.

Lead Question (2022):
Select the incorrect statement with respect to acquired immunity:
(1) Anamnestic response is elicited on subsequent encounters with the same pathogen
(2) Anamnestic response is due to memory of first encounter
(3) Acquired immunity is non-specific type of defence present at the time of birth
(4) Primary response is produced when our body encounters a pathogen for the first time

Explanation: Acquired immunity is specific and develops after first exposure to a pathogen. Statements (1), (2), and (4) correctly describe primary and secondary immune responses. Statement (3) is incorrect because acquired immunity is specific and not present at birth; innate immunity is the non-specific defense present at birth. Correct answer is option (3).

1. Memory cells are responsible for:
(1) Immediate primary response
(2) Faster secondary response
(3) Non-specific defense
(4) Phagocytosis

Explanation: Memory cells, produced during primary infection, remain in the body and recognize the pathogen upon re-exposure, eliciting a rapid and strong secondary immune response. Therefore, option (2) is correct.

2. Primary immune response is characterized by:
(1) Immediate and strong antibody production
(2) Slow onset and low antibody levels
(3) Absence of antigen recognition
(4) Non-specific defense activation

Explanation: Primary response occurs when the body encounters a pathogen for the first time. It is slow, with low antibody titers, and memory cells are generated for future encounters. Hence, option (2) is correct.

3. Secondary (anamnestic) immune response differs from primary response in that:
(1) It is slower
(2) It produces fewer antibodies
(3) It is faster and more effective
(4) It does not involve memory cells

Explanation: The secondary response is faster and more robust because memory B and T cells recognize the pathogen. It produces higher antibody titers compared to primary response. Therefore, option (3) is correct.

4. Which cells directly produce antibodies?
(1) T helper cells
(2) Plasma cells
(3) Memory T cells
(4) Macrophages

Explanation: Plasma cells, differentiated from B lymphocytes upon antigen stimulation, are responsible for secreting antibodies that neutralize pathogens. Hence, option (2) is correct.

5. Acquired immunity is specific because:
(1) It targets any pathogen
(2) It recognizes and responds to specific antigens
(3) It does not involve memory cells
(4) It is present at birth

Explanation: Acquired immunity is specific as it recognizes unique antigens on pathogens, producing tailored immune responses and generating memory cells for faster secondary response. Innate immunity is non-specific. Therefore, option (2) is correct.

6. Vaccination works by:
(1) Activating non-specific defenses
(2) Producing memory cells without causing disease
(3) Killing pathogens immediately
(4) Preventing antigen presentation

Explanation: Vaccines expose the body to antigens from pathogens without causing illness, stimulating production of memory B and T cells, enabling a rapid secondary immune response upon future exposure. Hence, option (2) is correct.

7. Assertion-Reason:
Assertion (A): Anamnestic response is stronger than primary response.
Reason (R): Memory cells facilitate rapid recognition and antibody production upon second exposure.
(1) Both A and R are true and R explains A
(2) Both A and R are true but R does not explain A
(3) A is true, R is false
(4) A is false, R is true

Explanation: The anamnestic response is faster and stronger due to memory cells recognizing the pathogen and rapidly producing antibodies. Both assertion and reason are true, and the reason explains the assertion. Correct answer is option (1).

8. Matching Type: Match the immune response with its feature:
A. Primary response – 1. Rapid and strong
B. Secondary response – 2. Slow and low antibody production
C. Innate immunity – 3. Non-specific, present at birth
(1) A–2, B–1, C–3
(2) A–1, B–2, C–3
(3) A–3, B–2, C–1
(4) A–2, B–3, C–1

Explanation: Primary response is slow with low antibodies (A–2), secondary response is rapid and strong (B–1), and innate immunity is non-specific and present from birth (C–3). Therefore, option (1) is correct.

9. Fill in the blank:
______ cells are long-lived and help in faster secondary immune response.

(1) Plasma
(2) Memory
(3) T helper
(4) Macrophages

Explanation: Memory cells are long-lived lymphocytes that remain after primary infection, recognizing previously encountered pathogens and facilitating a rapid, strong secondary response. Hence, option (2) is correct.

10. Choose the correct statements:
(a) Anamnestic response occurs on subsequent exposure
(b) Primary response is slower
(c) Acquired immunity is specific
(d) Innate immunity is specific

(1) a, b, c
(2) a, d
(3) b, d
(4) c, d

Explanation: Statements (a), (b), and (c) correctly describe acquired immunity and its features, including primary and secondary responses. Statement (d) is false as innate immunity is non-specific. Therefore, the correct answer is option (1).

Topic: Immunology
Subtopic: Autoimmune Disorders

Keyword Definitions:
• Autoimmune Disorder: Condition where the immune system attacks its own cells, mistaking them for foreign invaders.
• Immune System: Body’s defense mechanism against pathogens and abnormal cells.
• Rheumatoid Arthritis: Chronic autoimmune disease causing joint inflammation and tissue damage.
• Self-Antigen: Molecules produced by the body recognized as ‘self’ by a healthy immune system.
• Antibody: Protein produced by B cells that binds specific antigens.
• T Cells: Lymphocytes that mediate cellular immunity and can attack infected or abnormal cells.
• Inflammation: Response of tissues to injury or infection, often seen in autoimmune diseases.
• Tolerance: Immune system’s ability to ignore self-antigens.
• Pathogen: Disease-causing microorganism or virus.
• Autoantibody: Antibody produced against self-antigens, causing autoimmune damage.

Lead Question (2022):
Given below are two statements:
Statement I: Autoimmune disorder is a condition where body defense mechanism recognizes its own cells as foreign bodies.
Statement II: Rheumatoid arthritis is a condition where body does not attack self cells.
In the light of the above statements, choose the most appropriate answer from the options given below:
1. Both statement I and Statement II are incorrect
2. Statement I is correct but Statement II is incorrect
3. Statement I is incorrect but Statement II is correct
4. Both Statement I and Statement II are correct

Explanation: The correct answer is 2. Statement I is correct because autoimmune disorders occur when the immune system attacks self cells. Statement II is incorrect since rheumatoid arthritis is a classic autoimmune disease where the immune system attacks joint tissues, leading to inflammation and progressive joint damage.

Guessed MCQs:

1. Which antibody type is commonly elevated in autoimmune diseases?
Options:
(a) IgA
(b) IgE
(c) IgG
(d) IgM
Explanation: The correct answer is (c) IgG. IgG autoantibodies are often involved in autoimmune responses, attacking self-antigens and causing tissue damage. IgA, IgE, and IgM have specific roles in mucosal immunity, allergies, and primary immune responses, not primarily in autoimmunity.

2. Which organ is commonly affected in systemic lupus erythematosus?
Options:
(a) Kidney
(b) Liver
(c) Pancreas
(d) Lung
Explanation: The correct answer is (a) Kidney. Lupus nephritis occurs when autoantibodies target kidney tissues, causing inflammation and damage. Liver, pancreas, and lungs may be affected in specific autoimmune disorders, but the kidney is a primary target in SLE.

3. Assertion-Reason MCQ:
Assertion (A): T cells play a major role in autoimmune diseases.
Reason (R): They can attack self-antigens and trigger inflammation.
Options:
(a) Both A and R are true, R explains A
(b) Both A and R are true, R does not explain A
(c) A is true, R is false
(d) A is false, R is true
Explanation: The correct answer is (a). T cells mediate cellular immunity and can mistakenly recognize self-antigens, causing autoimmune damage and inflammation. This explains why T cells are central to the pathology of autoimmune diseases such as rheumatoid arthritis and multiple sclerosis.

4. Matching Type MCQ:
Match the autoimmune disease with the primary organ affected:
List - I List - II
(a) Type 1 Diabetes (i) Joints
(b) Rheumatoid Arthritis (ii) Pancreas
(c) Multiple Sclerosis (iii) Brain and Spinal Cord
Options:
1. a-ii, b-i, c-iii
2. a-i, b-ii, c-iii
3. a-iii, b-i, c-ii
4. a-ii, b-iii, c-i
Explanation: The correct answer is 1. Type 1 diabetes targets pancreatic beta cells, rheumatoid arthritis affects synovial joints, and multiple sclerosis attacks myelin in the brain and spinal cord, illustrating organ-specific autoimmune pathologies.

5. Which immune cell directly destroys self-cells in autoimmune diseases?
Options:
(a) Cytotoxic T cells
(b) B cells
(c) Macrophages
(d) NK cells
Explanation: The correct answer is (a) Cytotoxic T cells. These cells recognize self-antigens presented by MHC I molecules and induce apoptosis of target cells. B cells produce autoantibodies but do not directly kill cells, while macrophages and NK cells have different immune roles.

6. Single Correct Answer:
Which cytokine is associated with autoimmune inflammation?
Options:
(a) TNF-alpha
(b) IL-10
(c) IL-4
(d) TGF-beta
Explanation: The correct answer is (a) TNF-alpha. Tumor necrosis factor-alpha is a pro-inflammatory cytokine elevated in rheumatoid arthritis and other autoimmune diseases, promoting tissue damage. IL-10, IL-4, and TGF-beta are mostly anti-inflammatory or regulatory.

7. Fill in the Blanks:
Autoimmune disorders occur due to loss of __________.
Options:
(a) Immune tolerance
(b) Antigen specificity
(c) Lymphocyte production
(d) Inflammation
Explanation: The correct answer is (a) Immune tolerance. When tolerance to self-antigens is lost, the immune system attacks own tissues. Antigen specificity, lymphocyte production, and inflammation are components of immunity but do not directly cause autoimmunity.

8. Which autoantibody is characteristic of rheumatoid arthritis?
Options:
(a) Rheumatoid factor
(b) Anti-DNA antibody
(c) Anti-insulin antibody
(d) Anti-myelin antibody
Explanation: The correct answer is (a) Rheumatoid factor. It is an IgM antibody that targets IgG, forming immune complexes in joints. Anti-DNA is seen in lupus, anti-insulin in type 1 diabetes, and anti-myelin in multiple sclerosis.

9. Single Correct Answer:
Which therapy is commonly used to reduce autoimmune inflammation?
Options:
(a) Immunosuppressants
(b) Antibiotics
(c) Antivirals
(d) Vaccines
Explanation: The correct answer is (a) Immunosuppressants. Drugs such as corticosteroids or methotrexate dampen the immune response, reducing tissue damage in autoimmune diseases. Antibiotics, antivirals, and vaccines are for infections, not autoimmunity.

10. Choose the correct statements:
(i) Autoimmune disorders result from self-antigen recognition
(ii) Tolerance prevents autoimmunity
(iii) Rheumatoid arthritis is autoimmune
(iv) Bacteria are the primary cause
Options:
(a) i, ii, iii
(b) i, iii, iv
(c) ii, iv
(d) i, ii, iv
Explanation: The correct answer is (a) i, ii, iii. Autoimmune disorders arise from immune attack on self-antigens, tolerance prevents this response, and rheumatoid arthritis is an autoimmune disease. Bacteria are not the primary cause of autoimmune disorders.

Topic: Infectious Diseases
Subtopic: Parasitic, Bacterial, and Fungal Infections

Keyword Definitions:

• Filariasis: A parasitic disease caused by nematode worms like Wuchereria bancrofti, transmitted by mosquitoes.

• Amoebiasis: Intestinal infection caused by Entamoeba histolytica, leading to diarrhea and dysentery.

• Pneumonia: Inflammation of lungs, often caused by bacteria such as Haemophilus influenzae, resulting in difficulty in breathing.

• Ringworm: Superficial fungal infection of skin caused by dermatophytes like Trichophyton species.

• Wuchereria bancrofti: Parasitic worm responsible for lymphatic filariasis.

• Entamoeba histolytica: Protozoan parasite causing amoebic dysentery.

• Haemophilus influenzae: Gram-negative bacteria causing respiratory infections including pneumonia.

• Trichophyton: Genus of fungi causing dermatophytosis (ringworm).

• Parasitic infection: Disease caused by protozoans or worms infecting humans.

• Bacterial infection: Illness caused by pathogenic bacteria.

• Fungal infection: Disease caused by fungi affecting skin, nails, or internal organs.

Lead Question - 2021

Match List - I with List - II
List - I  List - II
(a) Filariasis  (i) Haemophilus influenzae
(b) Amoebiasis  (ii) Trichophyton
(c) Pneumonia  (iii) Wuchereria bancrofti
(d) Ringworm  (iv) Entamoeba histolytica
(1) (a)-(iii), (b)-(iv), (c)-(i), (d)-(ii)
(2) (a)-(i), (b)-(ii), (c)-(iv), (d)-(iii)
(3) (a)-(ii), (b)-(iii), (c)-(i), (d)-(iv)
(4) (a)-(iv), (b)-(i), (c)-(iii), (d)-(ii)

Explanation: Filariasis is caused by Wuchereria bancrofti (a-iii). Amoebiasis is due to Entamoeba histolytica (b-iv). Pneumonia can be caused by bacteria like Haemophilus influenzae (c-i). Ringworm is a fungal infection caused by Trichophyton species (d-ii). Correct answer is option (1).

1. Filariasis is transmitted by:
(1) Mosquitoes
(2) Contaminated water
(3) Direct skin contact
(4) Airborne droplets
Explanation: Filariasis is caused by Wuchereria bancrofti, transmitted via mosquito bites, which deposit larvae into the human bloodstream. It affects lymphatic vessels leading to elephantiasis. Water, skin contact, or airborne transmission are not relevant. Correct answer is option (1) Mosquitoes.

2. Amoebiasis primarily affects:
(1) Intestine
(2) Lungs
(3) Skin
(4) Liver
Explanation: Amoebiasis caused by Entamoeba histolytica mainly affects the intestine, leading to diarrhea and dysentery. Liver abscess can occur secondarily but intestine is the primary site. Lungs and skin are not directly affected. Correct answer is option (1) Intestine.

3. Pneumonia is inflammation of:
(1) Lungs
(2) Intestine
(3) Liver
(4) Skin
Explanation: Pneumonia involves inflammation of the alveoli in the lungs, caused by bacteria such as Haemophilus influenzae, viruses, or fungi. It results in difficulty in breathing, cough, and fever. Intestine, liver, and skin are not affected. Correct answer is option (1) Lungs.