This collection of 300 USMLE high-yield practice questions is designed for medical students preparing for USMLE Step 1 and Step 2 CK. Each clinical vignette MCQ includes detailed explanations to strengthen exam performance.
🧠PART 1 — CARDIOLOGY + PHYSIOLOGY + PHARMACOLOGY
Question 1
A 58-year-old man presents with crushing substernal chest pain radiating to the left arm. ECG shows ST elevation in leads II, III, and aVF. Which coronary artery is most likely occluded?
A. Left anterior descending artery
B. Left circumflex artery
C. Right coronary artery
D. Posterior descending artery
E. Diagonal branch
Answer: C. Right coronary artery
Explanation:
Leads II, III, and aVF represent the inferior wall of the heart.
Inferior wall MI = most commonly due to Right Coronary Artery (RCA) occlusion.
RCA supplies:
- SA node (60%)
- AV node (80%)
- Inferior wall of LV
Why others are wrong:
- LAD → anterior wall MI (V1–V4)
- LCX → lateral wall MI
- PDA → branch of RCA, not primary culprit usually
- Diagonal → branch of LAD
Question 2
A patient with heart failure is given a drug that increases intracellular calcium by inhibiting Na⁺/K⁺ ATPase. What drug was administered?
A. Furosemide
B. Digoxin
C. Metoprolol
D. Enalapril
E. Spironolactone
Answer: B. Digoxin
Explanation:
Digoxin inhibits Na⁺/K⁺ ATPase → increases intracellular Na⁺ → decreases Na⁺/Ca²⁺ exchange → increases intracellular Ca²⁺ → increased contractility.
High yield:
- Used in HFrEF + atrial fibrillation
- Toxicity: nausea, vision changes (yellow vision), arrhythmias
Question 3
A 25-year-old tall male presents with sudden chest pain and dyspnea. CXR shows widened mediastinum. He has long fingers and hypermobile joints. What is the most likely diagnosis?
A. Ehlers-Danlos syndrome
B. Marfan syndrome
C. Turner syndrome
D. Down syndrome
E. Homocystinuria
Answer: B. Marfan syndrome
Explanation:
Marfan = Fibrillin-1 mutation → weak connective tissue → risk of aortic dissection → widened mediastinum.
Associated findings:
- Tall
- Arachnodactyly
- Lens subluxation (upward)
- Aortic root dilation
Question 4
A patient with hypertension is given an ACE inhibitor. Which of the following is increased?
A. Angiotensin II
B. Bradykinin
C. Aldosterone
D. Renin suppression
E. Vasoconstriction
Answer: B. Bradykinin
Explanation:
ACE inhibitors:
- ↓ Angiotensin II
- ↓ Aldosterone
- ↑ Renin
- ↑ Bradykinin → causes cough + angioedema
Question 5
A 70-year-old man presents with syncope. ECG shows complete AV dissociation. What is the diagnosis?
A. First-degree AV block
B. Mobitz I
C. Mobitz II
D. Third-degree heart block
E. Atrial flutter
Answer: D. Third-degree heart block
Explanation:
Complete AV dissociation = atria and ventricles beat independently.
Treatment = pacemaker.
Question 6
Which electrolyte abnormality causes peaked T waves on ECG?
A. Hypokalemia
B. Hyperkalemia
C. Hypercalcemia
D. Hypocalcemia
E. Hyponatremia
Answer: B. Hyperkalemia
Explanation:
ECG changes in hyperkalemia:
- Peaked T waves
- Wide QRS
- Sine wave (severe)
Question 7
A patient develops ankle edema after starting amlodipine. Mechanism?
A. Increased venous return
B. Precapillary arteriolar dilation
C. RAAS activation
D. Sodium retention
E. Decreased cardiac output
Answer: B. Precapillary arteriolar dilation
Explanation:
Dihydropyridine CCBs cause arteriolar dilation → increased hydrostatic pressure → edema.
Question 8
Which drug reduces mortality in heart failure?
A. Digoxin
B. Furosemide
C. Metoprolol
D. Dopamine
E. Nitrates
Answer: C. Metoprolol
Explanation:
Drugs that reduce mortality in HFrEF:
- ACE inhibitors
- Beta blockers
- Spironolactone
- SGLT2 inhibitors
Digoxin improves symptoms but does NOT reduce mortality.
Question 9
A patient has bounding pulses and wide pulse pressure. Which condition?
A. Aortic stenosis
B. Mitral stenosis
C. Aortic regurgitation
D. Pulmonary hypertension
E. Cardiac tamponade
Answer: C. Aortic regurgitation
Explanation:
Aortic regurgitation → high systolic + low diastolic → wide pulse pressure.
Question 10
Which receptor is primarily responsible for increasing heart rate?
A. Alpha-1
B. Alpha-2
C. Beta-1
D. Beta-2
E. M2
Answer: C. Beta-1
Explanation:
Beta-1:
- ↑ HR
- ↑ Contractility
- ↑ Renin
(Continuing in same high-yield format…)
Question 11
ST elevation in V1–V4 → LAD occlusion
Answer: A
Question 12
Loop diuretics act on thick ascending limb
Answer: Inhibit Na-K-2Cl
Question 13
Hypertrophic cardiomyopathy → harsh systolic murmur ↑ with Valsalva
Answer: Dynamic LV outflow obstruction
Question 14
Cardiac tamponade → Beck triad
Answer: Hypotension + JVD + muffled heart sounds
Question 15
Warfarin mechanism → Inhibits vitamin K epoxide reductase
PART 2 — Respiratory + Acid–Base + Microbiology (High-Yield Clinical Style)
Question 26
A 65-year-old smoker presents with chronic cough and dyspnea. ABG shows:
pH 7.34, PaCO₂ 60 mmHg, HCO₃⁻ 32 mEq/L.
What is the acid–base disorder?
A. Acute respiratory acidosis
B. Chronic respiratory acidosis
C. Metabolic acidosis
D. Metabolic alkalosis
E. Mixed disorder
Answer: B. Chronic respiratory acidosis
Explanation:
- ↓ pH (slightly)
- ↑ CO₂
- ↑ HCO₃⁻ (renal compensation)
Chronic CO₂ retention (e.g., COPD) → kidneys retain bicarbonate.
Acute would not have elevated HCO₃⁻.
Question 27
A patient with asthma is given a drug that increases cAMP via β₂ stimulation. Which drug?
A. Ipratropium
B. Salmeterol
C. Montelukast
D. Theophylline
E. Prednisone
Answer: B. Salmeterol
Explanation:
β₂ agonists → activate adenylate cyclase → ↑ cAMP → bronchodilation.
Theophylline increases cAMP by PDE inhibition (different mechanism).
Question 28
A premature infant develops respiratory distress shortly after birth. CXR shows ground-glass appearance. Cause?
A. Surfactant deficiency
B. Meconium aspiration
C. Diaphragmatic hernia
D. Cystic fibrosis
E. Pneumonia
Answer: A. Surfactant deficiency
Explanation:
Neonatal RDS → deficiency of surfactant from type II pneumocytes → alveolar collapse.
Associated with maternal diabetes and prematurity.
Question 29
A 45-year-old man presents with hemoptysis and renal failure. Anti-GBM antibodies are detected. Diagnosis?
A. Granulomatosis with polyangiitis
B. Goodpasture syndrome
C. SLE
D. IgA nephropathy
E. Microscopic polyangiitis
Answer: B. Goodpasture syndrome
Explanation:
Anti-glomerular basement membrane antibodies → pulmonary hemorrhage + glomerulonephritis.
Question 30
Which organism causes atypical pneumonia with cold agglutinins?
A. Streptococcus pneumoniae
B. Mycoplasma pneumoniae
C. Legionella pneumophila
D. Chlamydia pneumoniae
E. Klebsiella
Answer: B. Mycoplasma pneumoniae
Explanation:
- Walking pneumonia
- No cell wall
- Cold agglutinins (IgM against RBCs)
Question 31
A 22-year-old presents with sudden dyspnea. Decreased breath sounds on one side and hyperresonance. Diagnosis?
A. Pulmonary embolism
B. Pneumonia
C. Pneumothorax
D. Asthma attack
E. Pleural effusion
Answer: C. Pneumothorax
Explanation:
Air in pleural space → hyperresonance + absent breath sounds.
Question 32
A patient hyperventilates during a panic attack. What happens to calcium?
A. Increased ionized calcium
B. Decreased ionized calcium
C. Increased total calcium
D. No change
E. Increased PTH
Answer: B. Decreased ionized calcium
Explanation:
Respiratory alkalosis → more calcium binds albumin → ↓ free calcium → tingling, tetany.
Question 33
Which bacteria is associated with cavitary lung lesions in alcoholics?
A. Staphylococcus aureus
B. Pseudomonas
C. Klebsiella pneumoniae
D. H. influenzae
E. Moraxella
Answer: C. Klebsiella pneumoniae
Explanation:
- Currant jelly sputum
- Upper lobe cavitation
- Alcoholics
Question 34
A patient with TB has caseating granulomas. Which immune cell is primarily responsible?
A. Neutrophils
B. Eosinophils
C. CD8 T cells
D. CD4 Th1 cells
E. B cells
Answer: D. CD4 Th1 cells
Explanation:
Th1 → IFN-γ → macrophage activation → granuloma formation.
Question 35
A patient on isoniazid develops peripheral neuropathy. Cause?
A. Vitamin B1 deficiency
B. Vitamin B6 deficiency
C. Vitamin B12 deficiency
D. Folate deficiency
E. Vitamin D deficiency
Answer: B. Vitamin B6 deficiency
Explanation:
Isoniazid inhibits pyridoxine metabolism → neuropathy.
Question 36
Metabolic acidosis with elevated anion gap is seen in:
A. Diarrhea
B. Renal tubular acidosis
C. Lactic acidosis
D. Vomiting
E. Hyperaldosteronism
Answer: C. Lactic acidosis
Explanation:
High anion gap causes (MUDPILES):
Methanol
Uremia
DKA
Propylene glycol
Isoniazid
Lactic acidosis
Ethylene glycol
Salicylates
Question 37
A cystic fibrosis patient has recurrent lung infections. Most common organism?
A. Strep pneumoniae
B. H influenzae
C. Pseudomonas aeruginosa
D. Legionella
E. TB
Answer: C. Pseudomonas aeruginosa
Explanation:
CF → thick mucus → chronic Pseudomonas colonization.
Question 38
Which condition causes decreased DLCO?
A. Asthma
B. Chronic bronchitis
C. Emphysema
D. Pneumonia
E. Pulmonary embolism
Answer: C. Emphysema
Explanation:
Destruction of alveolar walls → ↓ surface area → ↓ diffusion capacity.
Question 39
ARDS is characterized by:
A. Increased hydrostatic pressure
B. Increased capillary permeability
C. Decreased surfactant production
D. Bronchospasm
E. Pleural fluid
Answer: B. Increased capillary permeability
Explanation:
ARDS = noncardiogenic pulmonary edema → diffuse alveolar damage.
Question 40
A 50-year-old smoker with weight loss and SIADH likely has:
A. Adenocarcinoma
B. Squamous cell carcinoma
C. Small cell carcinoma
D. Large cell carcinoma
E. Carcinoid
Answer: C. Small cell carcinoma
Explanation:
Small cell lung cancer → ectopic ADH → SIADH.
Question 41
Primary respiratory alkalosis is caused by:
A. COPD
B. Panic attack
C. Opiate overdose
D. Pneumothorax
E. CHF
Answer: B. Panic attack
Question 42
Bronchiectasis is most associated with:
A. Reversible obstruction
B. Permanent airway dilation
C. Pleural effusion
D. Restrictive pattern
E. Surfactant deficiency
Answer: B. Permanent airway dilation
Question 43
Legionella pneumonia is treated with:
A. Penicillin
B. Azithromycin
C. Ceftriaxone
D. Vancomycin
E. Rifampin
Answer: B. Azithromycin
Question 44
Which causes respiratory acidosis?
A. Hyperventilation
B. Opioid overdose
C. Anxiety
D. Salicylate early
E. Fever
Answer: B. Opioid overdose
Question 45
Which TB drug causes optic neuritis?
A. Isoniazid
B. Rifampin
C. Pyrazinamide
D. Ethambutol
E. Streptomycin
Answer: D. Ethambutol
Question 46
Sarcoidosis is associated with:
A. Caseating granulomas
B. Noncaseating granulomas
C. Neutrophilic infiltrate
D. Eosinophilia
E. Fibrosis only
Answer: B. Noncaseating granulomas
Question 47
A patient with metabolic alkalosis likely has:
A. Diarrhea
B. Vomiting
C. Renal failure
D. DKA
E. Lactic acidosis
Answer: B. Vomiting
Question 48
Which asthma medication prevents leukotriene action?
A. Salbutamol
B. Ipratropium
C. Montelukast
D. Prednisone
E. Omalizumab
Answer: C. Montelukast
Question 49
Histoplasma capsulatum is commonly found in:
A. Bird droppings
B. Water systems
C. Soil only
D. Dairy
E. Skin
Answer: A. Bird droppings
Question 50
Which condition increases hemoglobin’s oxygen affinity (left shift)?
A. Fever
B. Acidosis
C. Increased 2,3-BPG
D. Fetal hemoglobin
E. Hypercapnia
Answer: D. Fetal hemoglobin
Explanation:
HbF binds oxygen more tightly → left shift.
PART 3 — Renal Physiology + Electrolytes + Nephrology (Questions 51–75)
Question 51
A 7-year-old boy develops periorbital edema after a respiratory infection. Urinalysis shows massive proteinuria. Renal biopsy shows effacement of podocyte foot processes on EM. Diagnosis?
A. FSGS
B. Membranous nephropathy
C. Minimal change disease
D. IgA nephropathy
E. Post-streptococcal GN
Answer: C. Minimal change disease
Explanation:
- Most common nephrotic syndrome in children
- Triggered by infection
- EM: podocyte effacement
- Responds to steroids
Question 52
A diabetic patient develops nephrotic syndrome. Biopsy shows mesangial expansion and Kimmelstiel-Wilson nodules. Diagnosis?
A. FSGS
B. Membranous nephropathy
C. Diabetic nephropathy
D. Amyloidosis
E. RPGN
Answer: C. Diabetic nephropathy
Explanation:
- Nodular glomerulosclerosis
- Due to nonenzymatic glycation
- Leading cause of ESRD
Question 53
Which diuretic works on the thick ascending limb?
A. Hydrochlorothiazide
B. Spironolactone
C. Furosemide
D. Acetazolamide
E. Amiloride
Answer: C. Furosemide
Explanation:
Loop diuretics inhibit Na⁺-K⁺-2Cl⁻ transporter.
Side effects: hypokalemia, ototoxicity.
Question 54
A patient has hyperkalemia with peaked T waves. Immediate treatment?
A. Insulin
B. Calcium gluconate
C. Kayexalate
D. Furosemide
E. Dialysis
Answer: B. Calcium gluconate
Explanation:
Calcium stabilizes cardiac membrane (does NOT lower K⁺).
Always first step if ECG changes.
Question 55
A patient with hematuria 2 days after URI likely has:
A. Post-strep GN
B. IgA nephropathy
C. Lupus nephritis
D. Membranous nephropathy
E. RPGN
Answer: B. IgA nephropathy
Explanation:
- Occurs within days of URI
- IgA deposition in mesangium
- “Synpharyngitic” hematuria
Question 56
Post-streptococcal GN occurs:
A. Immediately after infection
B. 1–3 weeks after infection
C. During infection
D. 6 months later
E. Only in adults
Answer: B. 1–3 weeks after infection
Question 57
Which condition causes nephritic syndrome?
A. Minimal change disease
B. FSGS
C. Membranous nephropathy
D. Post-strep GN
E. Diabetic nephropathy
Answer: D. Post-strep GN
Explanation:
Nephritic = hematuria + RBC casts + hypertension.
Question 58
A patient has polyuria after head trauma. Serum sodium is high. Diagnosis?
A. SIADH
B. Central diabetes insipidus
C. Nephrogenic DI
D. Addison disease
E. Primary polydipsia
Answer: B. Central diabetes insipidus
Explanation:
Head trauma → ↓ ADH → polyuria + hypernatremia.
Question 59
Which hormone increases sodium reabsorption in collecting duct?
A. ADH
B. ANP
C. Aldosterone
D. Renin
E. Cortisol
Answer: C. Aldosterone
Question 60
A patient on ACE inhibitor develops hyperkalemia. Mechanism?
A. Increased renin
B. Increased aldosterone
C. Decreased aldosterone
D. Increased ADH
E. Increased Na excretion
Answer: C. Decreased aldosterone
Question 61
Nephrotic syndrome is characterized by:
A. Hematuria
B. RBC casts
C. Protein >3.5 g/day
D. Low cholesterol
E. Hypertension always
Answer: C. Protein >3.5 g/day
Question 62
Which condition causes high anion gap metabolic acidosis?
A. Diarrhea
B. Renal tubular acidosis
C. DKA
D. Vomiting
E. Hyperaldosteronism
Answer: C. DKA
Question 63
Which part of nephron is impermeable to water?
A. Proximal tubule
B. Descending limb
C. Thick ascending limb
D. Collecting duct (with ADH)
E. Glomerulus
Answer: C. Thick ascending limb
Question 64
A patient has low potassium and metabolic alkalosis. Likely cause?
A. Diarrhea
B. Vomiting
C. DKA
D. Renal failure
E. Addison disease
Answer: B. Vomiting
Question 65
Which condition causes nephrotic syndrome in adults?
A. Minimal change
B. Membranous nephropathy
C. Post-strep
D. IgA nephropathy
E. Alport syndrome
Answer: B. Membranous nephropathy
Question 66
Renin is secreted by:
A. Macula densa
B. Juxtaglomerular cells
C. Proximal tubule
D. Collecting duct
E. Podocytes
Answer: B. Juxtaglomerular cells
Question 67
Which electrolyte abnormality causes U waves?
A. Hyperkalemia
B. Hypokalemia
C. Hypercalcemia
D. Hyponatremia
E. Hypermagnesemia
Answer: B. Hypokalemia
Question 68
SIADH causes:
A. Hypernatremia
B. Hypovolemia
C. Hyperkalemia
D. Hyponatremia
E. Polyuria
Answer: D. Hyponatremia
Question 69
Alport syndrome is due to defect in:
A. IgA
B. Collagen type IV
C. Podocytes
D. Complement
E. Mesangial cells
Answer: B. Collagen type IV
Question 70
A patient develops acute kidney injury after contrast. Cause?
A. ATN
B. RPGN
C. Membranous nephropathy
D. Pyelonephritis
E. IgA nephropathy
Answer: A. Acute tubular necrosis
Question 71
FSGS is associated with:
A. Diabetes
B. HIV
C. Hepatitis B
D. SLE
E. TB
Answer: B. HIV
Question 72
Which diuretic spares potassium?
A. Furosemide
B. HCTZ
C. Spironolactone
D. Acetazolamide
E. Mannitol
Answer: C. Spironolactone
Question 73
Renal tubular acidosis type 1 is due to:
A. Proximal bicarbonate loss
B. Distal H⁺ secretion defect
C. Aldosterone excess
D. Hyperkalemia only
E. Glomerular damage
Answer: B. Distal H⁺ secretion defect
Question 74
Which increases GFR?
A. Efferent arteriole constriction
B. Afferent constriction
C. Dehydration
D. Shock
E. NSAIDs
Answer: A. Efferent arteriole constriction
Question 75
Which electrolyte is highest intracellularly?
A. Sodium
B. Calcium
C. Potassium
D. Chloride
E. Bicarbonate
Answer: C. Potassium
PART 4 — Endocrinology (Diabetes, Thyroid, Adrenal, Pituitary)
Question 76
A 14-year-old boy presents with polyuria, polydipsia, weight loss, and fruity breath odor. Labs show glucose 450 mg/dL, positive ketones, and high anion gap metabolic acidosis. Diagnosis?
A. HHS
B. Type 2 DM
C. DKA
D. Lactic acidosis
E. Addison crisis
Answer: C. DKA
Explanation:
- Type 1 DM
- Insulin deficiency → lipolysis → ketone production
- High anion gap metabolic acidosis
HHS has no significant ketosis.
Question 77
Which electrolyte abnormality is commonly seen in DKA before treatment?
A. Hypokalemia
B. Hyperkalemia
C. Hypercalcemia
D. Hyponatremia only
E. Hypomagnesemia
Answer: B. Hyperkalemia
Explanation:
Total body potassium is low, but serum K⁺ is elevated due to acidosis shifting K⁺ out of cells.
Question 78
A patient with Type 2 DM is started on a drug that decreases hepatic gluconeogenesis and increases insulin sensitivity. Drug?
A. Sulfonylurea
B. Insulin
C. Metformin
D. DPP-4 inhibitor
E. GLP-1 agonist
Answer: C. Metformin
Explanation:
- First-line for Type 2 DM
- Risk: lactic acidosis
- Weight neutral or slight loss
Question 79
A patient develops hypoglycemia after taking a sulfonylurea. Mechanism?
A. Blocks insulin receptor
B. Inhibits glucagon
C. Closes K⁺ channels in β cells
D. Activates GLP-1
E. Decreases glucose absorption
Answer: C. Closes K⁺ channels in β cells
Explanation:
Sulfonylureas close ATP-sensitive K⁺ channels → depolarization → insulin release.
Question 80
A patient presents with heat intolerance, weight loss, tremor, and exophthalmos. Diagnosis?
A. Hashimoto
B. Subacute thyroiditis
C. Graves disease
D. Toxic adenoma
E. Riedel thyroiditis
Answer: C. Graves disease
Explanation:
- TSH receptor antibodies
- Exophthalmos
- Diffuse goiter
Question 81
Hashimoto thyroiditis is associated with:
A. TSH receptor stimulation
B. Anti-TPO antibodies
C. Iodine excess
D. TSH suppression
E. Hyperthyroidism only
Answer: B. Anti-TPO antibodies
Question 82
Which thyroid drug can cause agranulocytosis?
A. Levothyroxine
B. Methimazole
C. Propranolol
D. Iodine
E. Prednisone
Answer: B. Methimazole
Question 83
A patient with low cortisol, low aldosterone, and hyperpigmentation has:
A. Cushing syndrome
B. Secondary adrenal insufficiency
C. Addison disease
D. Pheochromocytoma
E. SIADH
Answer: C. Addison disease
Explanation:
Primary adrenal failure → ↑ ACTH → hyperpigmentation.
Question 84
Cushing syndrome is characterized by:
A. Weight loss
B. Hypotension
C. Moon face
D. Hyperkalemia
E. Hypoglycemia
Answer: C. Moon face
Question 85
Which tumor secretes catecholamines?
A. Adrenal adenoma
B. Pheochromocytoma
C. Craniopharyngioma
D. Prolactinoma
E. Thyroid adenoma
Answer: B. Pheochromocytoma
Explanation:
Triad:
- Headache
- Sweating
- Palpitations
Question 86
A patient with acromegaly has excess:
A. ACTH
B. GH
C. Prolactin
D. TSH
E. Cortisol
Answer: B. GH
Question 87
Prolactin secretion is inhibited by:
A. TRH
B. Dopamine
C. Estrogen
D. TSH
E. Oxytocin
Answer: B. Dopamine
Question 88
A patient has central obesity, striae, and muscle weakness. Cause?
A. High cortisol
B. Low cortisol
C. High T3
D. Low T4
E. High ADH
Answer: A. High cortisol
Question 89
Which hormone increases blood calcium?
A. Calcitonin
B. PTH
C. Insulin
D. ADH
E. TSH
Answer: B. PTH
Question 90
Hyperparathyroidism causes:
A. Low calcium
B. High phosphate
C. Kidney stones
D. Hypotension
E. Hypoglycemia
Answer: C. Kidney stones
Question 91
Which drug treats acromegaly?
A. Insulin
B. Octreotide
C. Methimazole
D. Ketoconazole
E. Fludrocortisone
Answer: B. Octreotide
Question 92
SIADH results in:
A. Hypernatremia
B. Hypovolemia
C. Hyponatremia
D. Hyperkalemia
E. Polyuria
Answer: C. Hyponatremia
Question 93
A thyroid storm is treated with:
A. Insulin
B. Propranolol
C. Dopamine
D. ACTH
E. Aldosterone
Answer: B. Propranolol
Question 94
Which lab pattern suggests primary hypothyroidism?
A. High T3, low TSH
B. Low T4, high TSH
C. Low TSH only
D. High T4 only
E. Normal TSH
Answer: B. Low T4, high TSH
Question 95
Which is most associated with MEN2?
A. Prolactinoma
B. Pheochromocytoma
C. Hashimoto
D. Addison
E. Acromegaly
Answer: B. Pheochromocytoma
Question 96
A patient with Type 1 DM has which antibody?
A. Anti-insulin receptor
B. Anti-GAD
C. Anti-TPO
D. Anti-dsDNA
E. Anti-GBM
Answer: B. Anti-GAD
Question 97
Which increases insulin secretion?
A. GLP-1
B. Cortisol
C. Epinephrine
D. GH
E. Glucagon
Answer: A. GLP-1
Question 98
Diabetes insipidus causes:
A. Hyperglycemia
B. Polyuria
C. Ketoacidosis
D. Hypertension
E. Hyperkalemia
Answer: B. Polyuria
Question 99
Which hormone is released from posterior pituitary?
A. TSH
B. ACTH
C. GH
D. ADH
E. Prolactin
Answer: D. ADH
Question 100
A patient with severe hypoglycemia is treated with:
A. Insulin
B. Glucagon
C. Metformin
D. Propranolol
E. Cortisol
Answer: B. Glucagon
PART 5 — Neurology (Stroke, Seizures, Neuroanatomy, CNS Pharmacology)
Questions 101–125
Question 101
A 68-year-old man suddenly develops right-sided weakness and expressive aphasia. Which artery is most likely occluded?
A. Posterior cerebral artery
B. Middle cerebral artery
C. Anterior cerebral artery
D. Basilar artery
E. Vertebral artery
Answer: B. Middle cerebral artery
Explanation:
MCA stroke causes:
- Contralateral face & arm weakness > leg
- Aphasia (if dominant hemisphere, usually left)
Question 102
Occlusion of anterior cerebral artery causes weakness primarily in:
A. Face
B. Arm
C. Leg
D. Tongue
E. Eye
Answer: C. Leg
Explanation:
ACA supplies medial frontal lobe → leg motor area.
Question 103
A patient has loss of pain and temperature on right body and left face. Lesion location?
A. Medial medulla
B. Lateral medulla
C. Internal capsule
D. Pons
E. Thalamus
Answer: B. Lateral medulla
Explanation:
Wallenberg syndrome (PICA infarct).
Question 104
A patient has resting tremor, rigidity, bradykinesia. Diagnosis?
A. Huntington disease
B. Alzheimer disease
C. Parkinson disease
D. ALS
E. MS
Answer: C. Parkinson disease
Explanation:
Loss of dopaminergic neurons in substantia nigra.
Question 105
Which drug increases dopamine in Parkinson disease?
A. Haloperidol
B. Levodopa
C. Phenytoin
D. Fluoxetine
E. Propranolol
Answer: B. Levodopa
Question 106
A 6-year-old boy has progressive muscle weakness and calf pseudohypertrophy. Diagnosis?
A. Myasthenia gravis
B. Duchenne muscular dystrophy
C. Becker dystrophy
D. ALS
E. MS
Answer: B. Duchenne muscular dystrophy
Explanation:
X-linked dystrophin mutation.
Question 107
Which neurotransmitter is decreased in Alzheimer disease?
A. Dopamine
B. Serotonin
C. Acetylcholine
D. GABA
E. Glutamate
Answer: C. Acetylcholine
Question 108
A patient with MS has which pathology?
A. Peripheral demyelination
B. CNS demyelination
C. Axonal degeneration only
D. NMJ destruction
E. Motor neuron death
Answer: B. CNS demyelination
Question 109
Myasthenia gravis involves antibodies against:
A. Dopamine receptors
B. Acetylcholine receptors
C. Sodium channels
D. Myelin
E. GABA receptors
Answer: B. Acetylcholine receptors
Question 110
Guillain-Barré syndrome is characterized by:
A. CNS demyelination
B. Ascending paralysis
C. Hyperreflexia
D. UMN lesion
E. Tremor
Answer: B. Ascending paralysis
Question 111
Which seizure type presents with brief loss of awareness and 3 Hz spike-wave pattern?
A. Tonic-clonic
B. Absence
C. Myoclonic
D. Focal
E. Status epilepticus
Answer: B. Absence seizure
Question 112
First-line drug for status epilepticus?
A. Phenytoin
B. Valproate
C. Diazepam
D. Carbamazepine
E. Levetiracetam
Answer: C. Diazepam
Question 113
A patient with temporal lobe seizure may experience:
A. Visual aura
B. Metallic taste
C. Sudden paralysis
D. Bilateral weakness
E. Loss of sensation
Answer: B. Metallic taste
Question 114
Huntington disease is due to:
A. Trinucleotide deletion
B. CAG repeat expansion
C. X-linked mutation
D. Mitochondrial mutation
E. Autoimmune
Answer: B. CAG repeat expansion
Question 115
A patient has dilated pupil and ptosis. Nerve involved?
A. CN II
B. CN III
C. CN IV
D. CN V
E. CN VI
Answer: B. CN III
Question 116
Which neurotransmitter is inhibitory in CNS?
A. Glutamate
B. Dopamine
C. Acetylcholine
D. GABA
E. Norepinephrine
Answer: D. GABA
Question 117
A patient with epidural hematoma has rupture of:
A. Bridging veins
B. Middle meningeal artery
C. Basilar artery
D. Internal carotid
E. Vertebral artery
Answer: B. Middle meningeal artery
Question 118
Subdural hematoma is caused by rupture of:
A. Artery
B. Bridging veins
C. Capillaries
D. Sinus
E. Aneurysm
Answer: B. Bridging veins
Question 119
Which drug treats neuropathic pain?
A. Ibuprofen
B. Morphine
C. Gabapentin
D. Aspirin
E. Penicillin
Answer: C. Gabapentin
Question 120
A patient with ALS shows:
A. Only UMN signs
B. Only LMN signs
C. Both UMN and LMN signs
D. Sensory loss
E. Tremor
Answer: C. Both UMN and LMN signs
Question 121
Wernicke encephalopathy is due to deficiency of:
A. B1
B. B6
C. B12
D. Folate
E. Vitamin D
Answer: A. Thiamine (B1)
Question 122
A patient cannot recognize objects but vision intact. Lesion?
A. Occipital lobe
B. Temporal lobe
C. Parietal lobe
D. Frontal lobe
E. Cerebellum
Answer: B. Temporal lobe
Question 123
Cerebellar lesion causes:
A. Spasticity
B. Hyperreflexia
C. Ataxia
D. Rigidity
E. Paralysis
Answer: C. Ataxia
Question 124
Which drug is used for absence seizures?
A. Phenytoin
B. Carbamazepine
C. Ethosuximide
D. Diazepam
E. Phenobarbital
Answer: C. Ethosuximide
Question 125
A patient with stroke receives tPA. Mechanism?
A. Inhibits platelet aggregation
B. Activates plasminogen
C. Blocks thrombin
D. Inhibits factor Xa
E. Decreases fibrin
Answer: B. Activates plasminogen
PART 6 — Microbiology (Bacteria + Antibiotics)
Questions 126–150
Question 126
A 25-year-old man presents with urethral discharge. Gram stain shows gram-negative diplococci inside neutrophils. Diagnosis?
A. Chlamydia trachomatis
B. Neisseria gonorrhoeae
C. Treponema pallidum
D. Mycoplasma
E. E. coli
Answer: B. Neisseria gonorrhoeae
Explanation:
- Gram-negative diplococci
- Intracellular in neutrophils
- Treat with ceftriaxone + azithromycin/doxycycline
Question 127
Which organism lacks a cell wall?
A. Streptococcus
B. Staphylococcus
C. Mycoplasma
D. Listeria
E. Neisseria
Answer: C. Mycoplasma
Explanation:
- No cell wall → not seen on Gram stain
- Resistant to β-lactams
Question 128
A patient develops pseudomembranous colitis after antibiotics. Cause?
A. E. coli
B. Clostridioides difficile
C. Salmonella
D. Shigella
E. Campylobacter
Answer: B. Clostridioides difficile
Question 129
Which toxin inhibits acetylcholine release causing flaccid paralysis?
A. Tetanus toxin
B. Botulinum toxin
C. Diphtheria toxin
D. Cholera toxin
E. Shiga toxin
Answer: B. Botulinum toxin
Question 130
Which organism causes “rice-water stools”?
A. EHEC
B. Vibrio cholerae
C. Salmonella
D. Shigella
E. Yersinia
Answer: B. Vibrio cholerae
Question 131
A patient with pneumonia produces rusty sputum. Organism?
A. Klebsiella
B. Staph aureus
C. Streptococcus pneumoniae
D. Legionella
E. Mycoplasma
Answer: C. Streptococcus pneumoniae
Question 132
MRSA resistance is due to:
A. β-lactamase
B. Altered PBP (PBP2a)
C. Efflux pump
D. Ribosomal mutation
E. Capsule
Answer: B. Altered PBP
Question 133
A patient with meningitis has gram-positive diplococci. Diagnosis?
A. Neisseria
B. Listeria
C. Streptococcus pneumoniae
D. E. coli
E. H. influenzae
Answer: C. Streptococcus pneumoniae
Question 134
Which organism is associated with neonatal meningitis?
A. S. aureus
B. Group B Streptococcus
C. Pseudomonas
D. TB
E. Legionella
Answer: B. Group B Streptococcus
Question 135
Which bacteria causes painless genital ulcer?
A. HSV
B. Syphilis (Treponema pallidum)
C. Gonorrhea
D. Chlamydia
E. HPV
Answer: B. Treponema pallidum
Question 136
Diphtheria toxin inhibits:
A. DNA polymerase
B. Ribosomal subunit
C. EF-2
D. Cell wall synthesis
E. ATP synthesis
Answer: C. EF-2
Question 137
Which antibiotic inhibits 30S ribosomal subunit?
A. Penicillin
B. Vancomycin
C. Tetracycline
D. Erythromycin
E. Ciprofloxacin
Answer: C. Tetracycline
Question 138
Vancomycin works by:
A. Inhibiting 50S
B. Blocking PBP
C. Binding D-Ala-D-Ala
D. DNA inhibition
E. Membrane disruption
Answer: C. Binding D-Ala-D-Ala
Question 139
A patient has hemolytic uremic syndrome after diarrhea. Organism?
A. ETEC
B. EHEC
C. Salmonella
D. Shigella
E. Vibrio
Answer: B. EHEC
Question 140
Which bacteria is oxidase positive?
A. E. coli
B. Klebsiella
C. Neisseria
D. Shigella
E. Proteus
Answer: C. Neisseria
Question 141
Pseudomonas is treated with:
A. Penicillin G
B. Amoxicillin
C. Piperacillin
D. Erythromycin
E. Vancomycin
Answer: C. Piperacillin
Question 142
Which antibiotic inhibits DNA gyrase?
A. Tetracycline
B. Ciprofloxacin
C. Vancomycin
D. Rifampin
E. Penicillin
Answer: B. Ciprofloxacin
Question 143
A patient develops gray pseudomembrane in throat. Cause?
A. Strep pyogenes
B. Diphtheria
C. EBV
D. Adenovirus
E. Influenza
Answer: B. Diphtheria
Question 144
Which bacteria produces superantigen causing toxic shock syndrome?
A. E. coli
B. Staph aureus
C. Salmonella
D. Shigella
E. TB
Answer: B. Staph aureus
Question 145
A child has strawberry tongue and rash. Diagnosis?
A. Measles
B. Scarlet fever
C. Rubella
D. Varicella
E. Fifth disease
Answer: B. Scarlet fever
(Caused by Streptococcus pyogenes toxin.)
Question 146
Listeria is treated with:
A. Ceftriaxone
B. Ampicillin
C. Vancomycin
D. Azithromycin
E. Ciprofloxacin
Answer: B. Ampicillin
Question 147
Which antibiotic causes red man syndrome?
A. Penicillin
B. Vancomycin
C. Tetracycline
D. Rifampin
E. Clindamycin
Answer: B. Vancomycin
Question 148
Rifampin inhibits:
A. DNA polymerase
B. RNA polymerase
C. Ribosome
D. Cell wall
E. ATP synthase
Answer: B. RNA polymerase
Question 149
Which bacteria is urease positive and causes peptic ulcer?
A. E. coli
B. H. pylori
C. Salmonella
D. Shigella
E. Vibrio
Answer: B. Helicobacter pylori
Question 150
Clindamycin inhibits:
A. 30S
B. 50S
C. DNA
D. Cell wall
E. Membrane
Answer: B. 50S ribosomal subunit
PART 7 — Virology (DNA/RNA Viruses, HIV, Hepatitis, Vaccines)
Questions 151–175
Question 151
Which virus is a double-stranded DNA virus?
A. Influenza
B. HIV
C. Hepatitis C
D. Adenovirus
E. Rabies
Answer: D. Adenovirus
Explanation:
Most DNA viruses are double-stranded except Parvovirus (single-stranded DNA).
Question 152
Which virus is enveloped, segmented, negative-sense RNA?
A. Measles
B. Influenza
C. Rabies
D. Polio
E. Hepatitis A
Answer: B. Influenza
Explanation:
Influenza:
- Enveloped
- Segmented
- Negative-sense RNA
- Undergoes antigenic shift & drift
Question 153
A patient with HIV has CD4 count of 150. Which infection is most likely?
A. Candida oral thrush
B. Pneumocystis jirovecii
C. CMV retinitis
D. TB
E. Toxoplasmosis
Answer: B. Pneumocystis jirovecii
Explanation:
PCP risk when CD4 < 200.
Question 154
Which HIV drug inhibits reverse transcriptase by mimicking nucleosides?
A. Protease inhibitor
B. Integrase inhibitor
C. NRTI
D. NNRTI
E. CCR5 antagonist
Answer: C. NRTI
Question 155
Hepatitis B surface antigen indicates:
A. Immunity
B. Past infection
C. Active infection
D. Vaccination
E. Cure
Answer: C. Active infection
Question 156
Which hepatitis virus is RNA and fecal-oral transmitted?
A. Hepatitis B
B. Hepatitis C
C. Hepatitis D
D. Hepatitis A
E. Hepatitis E only in US
Answer: D. Hepatitis A
Question 157
A patient develops vesicular rash along dermatome. Virus?
A. HSV-1
B. HSV-2
C. VZV
D. CMV
E. EBV
Answer: C. Varicella-zoster virus
Question 158
Which virus causes infectious mononucleosis?
A. CMV
B. EBV
C. HSV
D. Adenovirus
E. HIV
Answer: B. Epstein-Barr virus
Question 159
Which virus is associated with cervical cancer?
A. HSV
B. EBV
C. HPV
D. CMV
E. VZV
Answer: C. HPV
(High-risk types 16, 18.)
Question 160
A child has Koplik spots and rash starting at face. Virus?
A. Rubella
B. Measles
C. Varicella
D. Fifth disease
E. Mumps
Answer: B. Measles
Question 161
Which virus causes slapped cheek rash?
A. Measles
B. Rubella
C. Parvovirus B19
D. VZV
E. EBV
Answer: C. Parvovirus B19
Question 162
CMV infection in immunocompromised patients causes:
A. Kaposi sarcoma
B. Retinitis
C. Thrush
D. Pneumonia
E. Meningitis
Answer: B. CMV retinitis
Question 163
Which virus is bullet-shaped?
A. Influenza
B. Rabies
C. HIV
D. Polio
E. Rotavirus
Answer: B. Rabies
Question 164
Which vaccine is live attenuated?
A. IPV
B. MMR
C. Hepatitis B
D. Tetanus
E. Influenza injection
Answer: B. MMR
Question 165
Hepatitis D requires:
A. Hepatitis A
B. Hepatitis B
C. Hepatitis C
D. HIV
E. EBV
Answer: B. Hepatitis B
Question 166
Which HIV drug blocks gp41-mediated fusion?
A. Enfuvirtide
B. Zidovudine
C. Ritonavir
D. Efavirenz
E. Dolutegravir
Answer: A. Enfuvirtide
Question 167
Which virus causes bronchiolitis in infants?
A. Influenza
B. RSV
C. Adenovirus
D. Parainfluenza
E. Rhinovirus
Answer: B. RSV
Question 168
Rotavirus causes:
A. Bloody diarrhea
B. Severe watery diarrhea in children
C. Hepatitis
D. Meningitis
E. Rash
Answer: B. Severe watery diarrhea
Question 169
Which virus integrates into host genome?
A. Influenza
B. Retrovirus
C. Adenovirus
D. Polio
E. Rotavirus
Answer: B. Retrovirus (HIV)
Question 170
Which hepatitis is most likely to become chronic?
A. Hepatitis A
B. Hepatitis B
C. Hepatitis C
D. Hepatitis E
E. Hepatitis A & E
Answer: C. Hepatitis C
Question 171
Which virus causes Kaposi sarcoma?
A. EBV
B. HHV-8
C. CMV
D. HPV
E. HSV
Answer: B. HHV-8
Question 172
Influenza antigenic shift occurs due to:
A. Point mutation
B. Gene reassortment
C. Deletion
D. Integration
E. Reverse transcription
Answer: B. Gene reassortment
Question 173
Which virus causes croup?
A. RSV
B. Influenza
C. Parainfluenza
D. Measles
E. Adenovirus
Answer: C. Parainfluenza
Question 174
A patient has painful vesicles on lips. Virus?
A. HSV-1
B. HSV-2
C. EBV
D. CMV
E. HPV
Answer: A. HSV-1
Question 175
Which virus is non-enveloped and very stable in environment?
A. HIV
B. Influenza
C. Hepatitis C
D. Adenovirus
E. HSV
Answer: D. Adenovirus
PART 8 — Immunology (Hypersensitivity, Autoimmune, Immunodeficiency, Transplant)
Questions 176–200
Question 176
An immediate allergic reaction to peanuts is mediated by:
A. IgG
B. IgM
C. IgE
D. IgA
E. Complement
Answer: C. IgE
Explanation:
Type I hypersensitivity → IgE-mediated → mast cell degranulation → histamine release.
Question 177
Hemolytic disease of newborn due to Rh incompatibility is which hypersensitivity type?
A. Type I
B. Type II
C. Type III
D. Type IV
E. Type V
Answer: B. Type II
Explanation:
Type II = antibody-mediated cytotoxicity (IgG/IgM against cell surface antigens).
Question 178
Serum sickness is an example of:
A. Type I
B. Type II
C. Type III
D. Type IV
E. Autoimmune
Answer: C. Type III
Explanation:
Immune complex deposition (antigen-antibody complexes).
Question 179
Contact dermatitis is:
A. IgE-mediated
B. Antibody mediated
C. Immune complex
D. T-cell mediated
E. Complement mediated
Answer: D. T-cell mediated
Explanation:
Type IV hypersensitivity → delayed → T cells.
Question 180
Which immunoglobulin crosses placenta?
A. IgA
B. IgM
C. IgE
D. IgG
E. IgD
Answer: D. IgG
Question 181
Selective IgA deficiency presents with:
A. Severe bacterial infections
B. Recurrent mucosal infections
C. Severe viral infections
D. Complement deficiency
E. Autoimmune only
Answer: B. Recurrent mucosal infections
Question 182
DiGeorge syndrome results from:
A. B-cell deficiency
B. Thymic aplasia
C. Complement defect
D. NK deficiency
E. IgA deficiency
Answer: B. Thymic aplasia
Explanation:
22q11 deletion → absent thymus → T-cell deficiency.
Question 183
A patient with SLE has antibodies against:
A. dsDNA
B. Acetylcholine receptor
C. TSH receptor
D. Collagen IV
E. RBC membrane
Answer: A. dsDNA
Question 184
Graves disease is:
A. Type II hypersensitivity
B. Type III
C. Type IV
D. Immunodeficiency
E. Immune complex
Answer: A. Type II
(Antibodies stimulate TSH receptor.)
Question 185
Which complement pathway is antibody-dependent?
A. Alternative
B. Lectin
C. Classical
D. Intrinsic
E. Terminal
Answer: C. Classical
Question 186
Acute transplant rejection is mediated by:
A. IgE
B. T cells
C. Complement only
D. NK cells
E. B cells only
Answer: B. T cells
Question 187
Chronic granulomatous disease is due to defect in:
A. Antibody production
B. NADPH oxidase
C. Complement
D. T cells
E. B cells
Answer: B. NADPH oxidase
Question 188
Which cytokine activates macrophages?
A. IL-4
B. IL-5
C. IL-10
D. IFN-γ
E. TNF-β
Answer: D. IFN-γ
Question 189
A patient with HIV primarily loses:
A. CD8 cells
B. CD4 cells
C. B cells
D. NK cells
E. Macrophages
Answer: B. CD4 cells
Question 190
Anaphylaxis treatment of choice:
A. Antihistamine
B. Corticosteroid
C. Epinephrine
D. Oxygen
E. IV fluids only
Answer: C. Epinephrine
Question 191
Which cell presents antigen via MHC II?
A. RBC
B. Neutrophil
C. Macrophage
D. Platelet
E. Smooth muscle
Answer: C. Macrophage
Question 192
IgM is important because it:
A. Crosses placenta
B. First antibody produced
C. Secreted in breast milk
D. Binds allergens
E. Activates eosinophils
Answer: B. First antibody produced
Question 193
Which immunodeficiency causes recurrent Neisseria infections?
A. IgA deficiency
B. C3 deficiency
C. C5–C9 deficiency
D. T-cell deficiency
E. B-cell deficiency
Answer: C. C5–C9 deficiency
Question 194
SCID involves:
A. Only B cells
B. Only T cells
C. Both B and T cells
D. Only complement
E. Only IgA
Answer: C. Both B and T cells
Question 195
Rheumatoid arthritis is associated with:
A. Anti-dsDNA
B. Anti-CCP
C. Anti-TPO
D. Anti-GBM
E. Anti-AChR
Answer: B. Anti-CCP
Question 196
Which cell is primary in allergic asthma?
A. Neutrophil
B. Eosinophil
C. Macrophage
D. NK cell
E. Platelet
Answer: B. Eosinophil
Question 197
Immune complex deposition activates:
A. Dopamine
B. Complement
C. Insulin
D. Acetylcholine
E. Renin
Answer: B. Complement
Question 198
Which antibody is secreted in breast milk?
A. IgG
B. IgA
C. IgM
D. IgE
E. IgD
Answer: B. IgA
Question 199
Which interleukin stimulates eosinophils?
A. IL-1
B. IL-2
C. IL-4
D. IL-5
E. IL-10
Answer: D. IL-5
Question 200
Hyperacute transplant rejection is mediated by:
A. T cells
B. Preformed antibodies
C. NK cells
D. Complement deficiency
E. Cytokines
Answer: B. Preformed antibodies
PART 9 — Hematology (Anemias, Coagulation, Leukemia, Anticoagulants)
Questions 201–225
Question 201
A 25-year-old woman presents with fatigue. Labs show low hemoglobin, low MCV, low ferritin. Diagnosis?
A. Thalassemia
B. Iron deficiency anemia
C. Sideroblastic anemia
D. B12 deficiency
E. Aplastic anemia
Answer: B. Iron deficiency anemia
Explanation:
- Microcytic anemia
- Low ferritin
- Most common cause: chronic blood loss
Question 202
A patient with anemia has normal iron but low MCV and target cells. Diagnosis?
A. Iron deficiency
B. Thalassemia
C. B12 deficiency
D. Sickle cell
E. Aplastic anemia
Answer: B. Thalassemia
Question 203
Which anemia causes hypersegmented neutrophils?
A. Iron deficiency
B. Sickle cell
C. B12 deficiency
D. Thalassemia
E. Hemolytic anemia
Answer: C. B12 deficiency
Question 204
A patient with sickle cell disease has mutation in:
A. Alpha globin
B. Beta globin
C. Iron metabolism
D. Erythropoietin
E. Myosin
Answer: B. Beta globin
Question 205
G6PD deficiency leads to:
A. Spherocytes
B. Bite cells
C. Target cells
D. Schistocytes
E. Macrocytes
Answer: B. Bite cells
Question 206
Aplastic anemia results from:
A. Increased RBC destruction
B. Bone marrow failure
C. Iron deficiency
D. B12 deficiency
E. Autoimmune hemolysis
Answer: B. Bone marrow failure
Question 207
Which vitamin deficiency causes neurologic symptoms and anemia?
A. Iron
B. Folate
C. B12
D. Vitamin C
E. Vitamin K
Answer: C. B12
Question 208
Hemophilia A is deficiency of:
A. Factor VIII
B. Factor IX
C. Factor VII
D. Factor X
E. Factor V
Answer: A. Factor VIII
Question 209
Prolonged PT but normal PTT suggests deficiency of:
A. Factor VIII
B. Factor IX
C. Factor VII
D. Factor XI
E. Factor XII
Answer: C. Factor VII
Question 210
Warfarin inhibits:
A. Thrombin
B. Factor Xa
C. Vitamin K epoxide reductase
D. Platelet aggregation
E. Fibrinogen
Answer: C. Vitamin K epoxide reductase
Question 211
Heparin works by activating:
A. Protein C
B. Protein S
C. Antithrombin III
D. Plasmin
E. Fibrin
Answer: C. Antithrombin III
Question 212
A patient on heparin develops thrombocytopenia. Cause?
A. Bone marrow failure
B. HIT
C. DIC
D. TTP
E. ITP
Answer: B. Heparin-induced thrombocytopenia
Question 213
Which leukemia is associated with Auer rods?
A. ALL
B. AML
C. CLL
D. CML
E. Hodgkin
Answer: B. AML
Question 214
Philadelphia chromosome is seen in:
A. AML
B. ALL
C. CML
D. CLL
E. Hodgkin
Answer: C. CML
Question 215
Which lymphoma has Reed-Sternberg cells?
A. Non-Hodgkin
B. Hodgkin lymphoma
C. CLL
D. AML
E. CML
Answer: B. Hodgkin lymphoma
Question 216
ITP causes:
A. Low platelets
B. High platelets
C. RBC destruction
D. Clot formation
E. DIC
Answer: A. Low platelets
Question 217
DIC is characterized by:
A. Thrombosis only
B. Bleeding only
C. Both thrombosis and bleeding
D. High platelets
E. Normal PT
Answer: C. Both thrombosis and bleeding
Question 218
Which lab value increases in hemolytic anemia?
A. Haptoglobin
B. LDH
C. Platelets
D. Hemoglobin
E. Ferritin
Answer: B. LDH
(Haptoglobin decreases.)
Question 219
Polycythemia vera is associated with mutation in:
A. BCR-ABL
B. JAK2
C. p53
D. RAS
E. MYC
Answer: B. JAK2
Question 220
Which anticoagulant directly inhibits thrombin?
A. Warfarin
B. Heparin
C. Dabigatran
D. Aspirin
E. Clopidogrel
Answer: C. Dabigatran
Question 221
Aspirin inhibits:
A. COX
B. Thrombin
C. Factor Xa
D. Fibrin
E. ADP receptor
Answer: A. COX
Question 222
Clopidogrel inhibits:
A. COX
B. Thrombin
C. ADP receptor
D. Vitamin K
E. Factor Xa
Answer: C. ADP receptor
Question 223
A patient with DVT is treated with rivaroxaban. It inhibits:
A. Thrombin
B. Factor Xa
C. Platelets
D. Fibrin
E. Vitamin K
Answer: B. Factor Xa
Question 224
Which anemia is associated with chronic disease?
A. High iron
B. Low ferritin
C. High ferritin
D. Macrocytosis
E. Hemolysis
Answer: C. High ferritin
Question 225
Which disease causes microangiopathic hemolytic anemia?
A. ITP
B. TTP
C. Iron deficiency
D. Aplastic anemia
E. Thalassemia
Answer: B. TTP
PART 10 — Gastroenterology (Liver, Pancreas, IBD, GI Pathology)
Questions 226–250
Question 226
A 45-year-old man with history of alcohol use presents with epigastric pain radiating to the back. Elevated lipase. Diagnosis?
A. Cholecystitis
B. Peptic ulcer
C. Acute pancreatitis
D. GERD
E. Appendicitis
Answer: C. Acute pancreatitis
Explanation:
- Epigastric pain → radiates to back
- Elevated lipase (more specific than amylase)
- Common causes: alcohol, gallstones
Question 227
Which electrolyte abnormality is seen in acute pancreatitis?
A. Hypercalcemia
B. Hypocalcemia
C. Hypernatremia
D. Hyperkalemia
E. Hypermagnesemia
Answer: B. Hypocalcemia
Explanation:
Fat necrosis → calcium soap formation → ↓ serum calcium.
Question 228
A patient with RUQ pain after fatty meal has gallstones. Most common stone type?
A. Pigment stone
B. Calcium stone
C. Cholesterol stone
D. Bilirubin stone
E. Mixed stone
Answer: C. Cholesterol stone
Question 229
A patient with ulcerative colitis is at increased risk of:
A. Small bowel cancer
B. Colon cancer
C. Pancreatic cancer
D. Gastric cancer
E. Esophageal cancer
Answer: B. Colon cancer
Question 230
Crohn disease commonly affects:
A. Rectum only
B. Colon only
C. Terminal ileum
D. Stomach only
E. Esophagus
Answer: C. Terminal ileum
Question 231
Which feature distinguishes Crohn from ulcerative colitis?
A. Continuous lesions
B. Rectal involvement
C. Transmural inflammation
D. Bloody diarrhea
E. Colon cancer risk
Answer: C. Transmural inflammation
Question 232
A patient has jaundice and elevated unconjugated bilirubin. Cause?
A. Hemolysis
B. Obstruction
C. Hepatitis
D. Cholestasis
E. Pancreatitis
Answer: A. Hemolysis
Question 233
Hepatitis B is transmitted via:
A. Fecal-oral
B. Blood and sexual contact
C. Airborne
D. Skin contact
E. Water
Answer: B. Blood and sexual contact
Question 234
Which liver enzyme is most specific for alcohol use?
A. ALT
B. AST
C. ALP
D. GGT
E. LDH
Answer: D. GGT
Question 235
AST:ALT ratio >2 suggests:
A. Viral hepatitis
B. Alcoholic liver disease
C. NAFLD
D. Hemolysis
E. Cirrhosis only
Answer: B. Alcoholic liver disease
Question 236
A patient with cirrhosis develops ascites. Mechanism?
A. Increased oncotic pressure
B. Portal hypertension
C. Decreased ADH
D. Increased albumin
E. Hypercalcemia
Answer: B. Portal hypertension
Question 237
Which complication is seen in cirrhosis?
A. Hyperalbuminemia
B. Esophageal varices
C. Hypertension
D. Polycythemia
E. Hypernatremia
Answer: B. Esophageal varices
Question 238
A patient with GERD is treated with omeprazole. Mechanism?
A. H2 blockade
B. Proton pump inhibition
C. Antacid
D. Motility increase
E. Mucosal coating
Answer: B. Proton pump inhibition
Question 239
H. pylori increases risk of:
A. Esophageal cancer
B. Gastric cancer
C. Pancreatic cancer
D. Colon cancer
E. Liver cancer
Answer: B. Gastric cancer
Question 240
A patient has severe abdominal pain out of proportion to exam. Diagnosis?
A. Appendicitis
B. Pancreatitis
C. Mesenteric ischemia
D. Gastritis
E. IBS
Answer: C. Mesenteric ischemia
Question 241
Which vitamin deficiency occurs in Crohn disease?
A. Vitamin C
B. Vitamin A
C. Vitamin B12
D. Vitamin K
E. Vitamin D
Answer: C. Vitamin B12
(Terminal ileum involvement.)
Question 242
Which hepatitis has highest risk of chronic infection?
A. A
B. B
C. C
D. D
E. E
Answer: C. Hepatitis C
Question 243
Which tumor marker is elevated in hepatocellular carcinoma?
A. CEA
B. AFP
C. CA-125
D. PSA
E. CA 19-9
Answer: B. AFP
Question 244
A patient has clay-colored stools and dark urine. Cause?
A. Hemolysis
B. Obstructive jaundice
C. Viral hepatitis
D. Pancreatitis
E. IBS
Answer: B. Obstructive jaundice
Question 245
Which bacteria causes peptic ulcer?
A. E. coli
B. H. pylori
C. Salmonella
D. Shigella
E. Vibrio
Answer: B. Helicobacter pylori
Question 246
Which enzyme is elevated in cholestasis?
A. ALT
B. AST
C. ALP
D. CK
E. LDH
Answer: C. ALP
Question 247
Celiac disease is associated with antibodies against:
A. dsDNA
B. Tissue transglutaminase
C. TSH receptor
D. GBM
E. RBC
Answer: B. Tissue transglutaminase
Question 248
Which cancer is associated with Barrett esophagus?
A. Squamous cell
B. Adenocarcinoma
C. Small cell
D. Lymphoma
E. Sarcoma
Answer: B. Adenocarcinoma
Question 249
Which condition causes painless jaundice and weight loss?
A. Gallstones
B. Pancreatitis
C. Pancreatic cancer
D. Hepatitis
E. IBS
Answer: C. Pancreatic cancer
Question 250
Which drug is used to treat hepatic encephalopathy?
A. Omeprazole
B. Lactulose
C. Metformin
D. Warfarin
E. Prednisone
Answer: B. Lactulose
Explanation:
Lactulose decreases ammonia absorption in gut.
PART 11 — Musculoskeletal & Rheumatology
Questions 251–275
Question 251
A 55-year-old woman presents with bilateral hand pain and morning stiffness lasting >1 hour. Diagnosis?
A. Osteoarthritis
B. Rheumatoid arthritis
C. Gout
D. Septic arthritis
E. SLE
Answer: B. Rheumatoid arthritis
Explanation:
- Symmetric joint involvement
- Morning stiffness >1 hour
- Autoimmune synovitis
Question 252
Which antibody is most specific for rheumatoid arthritis?
A. ANA
B. RF
C. Anti-CCP
D. Anti-dsDNA
E. Anti-GBM
Answer: C. Anti-CCP
Question 253
Osteoarthritis is characterized by:
A. Autoimmune destruction
B. Cartilage degeneration
C. Synovial pannus
D. Hyperuricemia
E. Immune complex deposition
Answer: B. Cartilage degeneration
Question 254
Gout is caused by deposition of:
A. Calcium pyrophosphate
B. Uric acid crystals
C. Cholesterol
D. Immune complexes
E. Iron
Answer: B. Uric acid crystals
Question 255
Gout crystals appear as:
A. Positive birefringent
B. Negative birefringent
C. Round
D. Non-crystalline
E. Spiral
Answer: B. Negative birefringent
Question 256
Pseudogout involves deposition of:
A. Uric acid
B. Calcium pyrophosphate
C. Iron
D. Copper
E. Cholesterol
Answer: B. Calcium pyrophosphate
Question 257
Ankylosing spondylitis is associated with:
A. HLA-B27
B. HLA-DR4
C. HLA-DQ2
D. HLA-DQ8
E. HLA-B51
Answer: A. HLA-B27
Question 258
A patient has back pain that improves with exercise and worsens with rest. Diagnosis?
A. Osteoarthritis
B. RA
C. Ankylosing spondylitis
D. Gout
E. SLE
Answer: C. Ankylosing spondylitis
Question 259
SLE is associated with:
A. Anti-dsDNA
B. Anti-CCP
C. Anti-TPO
D. Anti-AChR
E. Anti-GBM only
Answer: A. Anti-dsDNA
Question 260
Which drug is first-line for acute gout attack?
A. Allopurinol
B. Colchicine
C. Methotrexate
D. Prednisone only
E. Warfarin
Answer: B. Colchicine
Question 261
Allopurinol works by inhibiting:
A. COX
B. Xanthine oxidase
C. Uric acid excretion
D. IL-1
E. TNF
Answer: B. Xanthine oxidase
Question 262
A child presents with bone pain and high alkaline phosphatase. Diagnosis?
A. Osteoporosis
B. Osteomalacia
C. Paget disease
D. RA
E. Scurvy
Answer: C. Paget disease
Question 263
Osteoporosis is characterized by:
A. Increased bone density
B. Decreased bone mass
C. Infection
D. Inflammation
E. Crystal deposition
Answer: B. Decreased bone mass
Question 264
Which vitamin deficiency causes osteomalacia?
A. Vitamin C
B. Vitamin A
C. Vitamin D
D. Vitamin K
E. B12
Answer: C. Vitamin D
Question 265
Which disease causes butterfly rash and photosensitivity?
A. RA
B. SLE
C. Psoriasis
D. Dermatomyositis
E. Scleroderma
Answer: B. SLE
Question 266
Dermatomyositis is associated with:
A. Muscle weakness
B. Joint swelling
C. Bone fracture
D. Uric acid crystals
E. Autoimmune kidney damage
Answer: A. Muscle weakness
Question 267
Which drug is disease-modifying in RA?
A. Ibuprofen
B. Methotrexate
C. Colchicine
D. Allopurinol
E. Acetaminophen
Answer: B. Methotrexate
Question 268
Which antibody is associated with scleroderma?
A. Anti-centromere
B. Anti-CCP
C. Anti-dsDNA
D. Anti-GBM
E. Anti-TPO
Answer: A. Anti-centromere
Question 269
A patient with bone pain and anemia has punched-out skull lesions. Diagnosis?
A. Osteoporosis
B. Multiple myeloma
C. Paget
D. RA
E. SLE
Answer: B. Multiple myeloma
Question 270
Which cytokine is targeted in RA therapy?
A. IL-1
B. IL-5
C. TNF-alpha
D. IFN-gamma
E. IL-10
Answer: C. TNF-alpha
Question 271
Which joint is most commonly affected in gout?
A. Knee
B. Hip
C. First MTP
D. Shoulder
E. Elbow
Answer: C. First MTP
Question 272
Osteomyelitis in sickle cell disease is commonly caused by:
A. Staph aureus
B. Salmonella
C. E. coli
D. Pseudomonas
E. TB
Answer: B. Salmonella
Question 273
Which autoimmune disease affects small vessels and causes purpura?
A. RA
B. SLE
C. Henoch-Schönlein purpura
D. Gout
E. Osteoarthritis
Answer: C. Henoch-Schönlein purpura
Question 274
A patient with proximal muscle weakness and elevated CK likely has:
A. Osteoarthritis
B. Myositis
C. Gout
D. RA
E. SLE
Answer: B. Myositis
Question 275
Which medication treats osteoporosis?
A. Bisphosphonates
B. Methotrexate
C. Colchicine
D. Allopurinol
E. Prednisone long-term
Answer: A. Bisphosphonates
PART 12 — Psychiatry (Mood, Anxiety, Psychosis, Pharmacology)
Questions 276–300
Question 276
A 25-year-old woman has depressed mood, anhedonia, insomnia, and fatigue for 3 weeks. Diagnosis?
A. Bipolar disorder
B. Major depressive disorder
C. Dysthymia
D. Adjustment disorder
E. Cyclothymia
Answer: B. Major depressive disorder
Explanation:
≥2 weeks of depressed mood or anhedonia + neurovegetative symptoms.
Question 277
First-line treatment for major depression?
A. Lithium
B. Haloperidol
C. SSRI
D. Benzodiazepine
E. Valproate
Answer: C. SSRI
Question 278
Fluoxetine works by:
A. Blocking dopamine
B. Blocking serotonin reuptake
C. Increasing GABA
D. Blocking NE
E. Blocking acetylcholine
Answer: B. Blocking serotonin reuptake
Question 279
Serotonin syndrome presents with:
A. Bradycardia
B. Muscle rigidity, hyperreflexia
C. Hypothermia
D. Constipation
E. Hypotension
Answer: B. Muscle rigidity, hyperreflexia
Question 280
A patient has periods of mania and depression. Diagnosis?
A. MDD
B. Bipolar disorder
C. Schizophrenia
D. Anxiety disorder
E. OCD
Answer: B. Bipolar disorder
Question 281
Lithium toxicity presents with:
A. Hypotension
B. Tremor and confusion
C. Rash
D. Agranulocytosis
E. Seizures only
Answer: B. Tremor and confusion
Question 282
A patient hears voices commenting on behavior for 6 months. Diagnosis?
A. Schizoaffective
B. Schizophrenia
C. Brief psychotic disorder
D. Bipolar
E. Delusional disorder
Answer: B. Schizophrenia
Question 283
Positive symptoms of schizophrenia are due to:
A. Decreased dopamine
B. Increased dopamine
C. Low serotonin
D. Low GABA
E. Low NE
Answer: B. Increased dopamine
Question 284
Haloperidol blocks:
A. Serotonin
B. Dopamine D2
C. GABA
D. Acetylcholine
E. NE
Answer: B. Dopamine D2
Question 285
Which side effect is common with antipsychotics?
A. Hypercalcemia
B. Extrapyramidal symptoms
C. Hypoglycemia
D. Renal failure
E. Hypernatremia
Answer: B. Extrapyramidal symptoms
Question 286
A patient develops muscle rigidity, fever, high CK after antipsychotic. Diagnosis?
A. Serotonin syndrome
B. NMS
C. Malignant hyperthermia
D. Heat stroke
E. Sepsis
Answer: B. Neuroleptic malignant syndrome
Question 287
First-line treatment for panic disorder?
A. Lithium
B. SSRI
C. Haloperidol
D. Valproate
E. Clozapine
Answer: B. SSRI
Question 288
Benzodiazepines act by:
A. Blocking dopamine
B. Increasing GABA-A activity
C. Blocking serotonin
D. Increasing NE
E. Blocking glutamate
Answer: B. Increasing GABA-A activity
Question 289
Which disorder involves intrusive thoughts and repetitive behaviors?
A. GAD
B. OCD
C. PTSD
D. Bipolar
E. Schizophrenia
Answer: B. OCD
Question 290
A patient exposed to trauma has flashbacks for 2 months. Diagnosis?
A. Acute stress disorder
B. PTSD
C. Adjustment disorder
D. GAD
E. MDD
Answer: B. PTSD
Question 291
Bulimia nervosa is characterized by:
A. Weight loss only
B. Binge eating with purging
C. No eating
D. Psychosis
E. Mania
Answer: B. Binge eating with purging
Question 292
Anorexia nervosa presents with:
A. Obesity
B. Hyperphagia
C. Fear of gaining weight
D. Psychosis
E. Mania
Answer: C. Fear of gaining weight
Question 293
A patient has elevated mood, decreased need for sleep for 3 days. Diagnosis?
A. Mania
B. Hypomania
C. Depression
D. Schizophrenia
E. OCD
Answer: B. Hypomania
Question 294
Which antidepressant is also used for smoking cessation?
A. Fluoxetine
B. Sertraline
C. Bupropion
D. Paroxetine
E. Citalopram
Answer: C. Bupropion
Question 295
Clozapine side effect:
A. Agranulocytosis
B. Hypernatremia
C. Kidney stones
D. Hypoglycemia
E. Hearing loss
Answer: A. Agranulocytosis
Question 296
Which neurotransmitter is low in depression?
A. Dopamine
B. Serotonin
C. GABA
D. Glutamate
E. Acetylcholine
Answer: B. Serotonin
Question 297
A patient is anxious most days for 6 months. Diagnosis?
A. Panic disorder
B. GAD
C. OCD
D. PTSD
E. Bipolar
Answer: B. Generalized anxiety disorder
Question 298
Which drug treats alcohol withdrawal?
A. SSRI
B. Benzodiazepine
C. Haloperidol
D. Lithium
E. Clozapine
Answer: B. Benzodiazepine
Question 299
A patient with schizophrenia has flat affect and lack of motivation. These are:
A. Positive symptoms
B. Negative symptoms
C. Mood symptoms
D. Anxiety
E. Mania
Answer: B. Negative symptoms
Question 300
Which drug stabilizes mood in bipolar disorder?
A. Fluoxetine
B. Lithium
C. Diazepam
D. Haloperidol
E. Sertraline
Answer: B. Lithium
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