NBME CBSE ACTUAL TEST QUIZ BANK 2024/2025| REAL
EXAM QUESTIONS AND 100% CORRECT DETAILED
ANSWERS (USMLE STEP 1) MEDICAL EXAMINATION
A 62-year-old woman is diagnosed with osteoporosis and prescribed a bisphosphonate. What is the expected
beneficial effect of the drug?
Answer: Decreased osteoclast activity
A cohort study of elderly women finds that the relative risk for hip fractures among those who exercise
regularly is 1.2, with a 95% confidence interval of 1.1 to 1.8. What conclusion can be drawn about the effect of
exercise on hip fracture risk?
Answer: Statistically significant overall increased risk
A 52-year-old man presents to the ER with chest pain radiating to his jaw while shoveling snow. His pulse is
80/min, and blood pressure is 130/70. What is the mechanism of action of the most immediate treatment?
Answer: Increased nitric oxide concentration
A 24-year-old woman spills hot grease on her left leg while working at a fast-food restaurant. Examination
reveals a 7 cm pink, soft, granular, edematous wound. The formation of this tissue is most likely due to the
increased activity of which factor?
Answer: Vascular Endothelial Growth Factor (VEGF)
VEGF stimulates angiogenesis.
Type III collagen is involved in early wound repair and blood vessel formation.
A 27-year-old man involved in a motor vehicle collision has a skull X-ray revealing a linear, non-depressed
basal skull fracture. His serum osmolarity is increased, and urine osmolarity is decreased. Following
administration of desmopressin, urine osmolarity increases. The effect of desmopressin is due to activation of
which pathway?
Answer: Adenylyl cyclase (V2 receptor activation)
A 10-month-old boy with a four-day history of fever and cough attends a daycare center. Chest examination
reveals intercostal retractions, bilateral diffuse wheezing, and expiratory rhonchi. What property does the most
likely infectious agent have?
Answer: Mediates cell entry via a fusion protein
,A 17-year-old girl arrives at the ED 15 minutes after being stung by a bee. She reports mild lightheadedness but
has no difficulty swallowing. Bilateral wheezing is noted. What is the most appropriate pharmacologic
treatment?
Answer: Beta-2 agonist
A 14-year-old boy presents with a two-day history of sore throat, fever peaking in the late afternoon, and
fatigue lasting one week. He recently had sexual intercourse with one partner. Physical examination reveals
cervical lymphadenopathy and pharyngeal erythema with a creamy exudate. What is the diagnosis?
Answer: Infectious mononucleosis
A 57-year-old man undergoes radiation therapy for squamous cell carcinoma of the lung. Despite treatment, the
tumor continues to grow, and he dies six months later. The tumor's progression is due to a defect in which phase
of the cell cycle?
Answer: G1 phase
A 28-year-old man who lived in sub-Saharan Africa before moving to the U.S. presents with a temperature of
100.4°F. Imaging reveals bilateral hydroureter and hydronephrosis. Biopsy shows marked fibrosis and scattered
granulomas. What is the most likely diagnosis?
Answer: Schistosomiasis
A couple has a family history of alpha-thalassemia. The woman has a one-gene deletion, and the man has a
two-gene deletion in trans. What percentage of their offspring will inherit a two-gene deletion?
Answer: 50%
A previously healthy 40-year-old woman is brought to the ED by her husband due to a two-day history of fever,
lethargy, and confusion. Physical examination reveals scattered petechiae and ecchymoses on the lower
extremities. Laboratory findings show 3+ polychromasia, 3+ schistocytes, and low platelet count. What is the
most likely diagnosis?
Answer: Thrombotic thrombocytopenic purpura (TTP)
A 16-year-old boy is admitted to the ER after sustaining a knife wound to the left side of his chest. A chest X-
ray reveals an air-fluid level on the left side, partial lung collapse, and an elevated stomach bubble. The
mediastinum remains midline. What is the diagnosis?
Answer: Tension hemopneumothorax
A 49-year-old woman with coronary artery disease has a blood pressure of 140/90, high cholesterol, LDL of
190, and triglycerides of 350. She is prescribed atorvastatin and losartan. What are the expected effects on her
lipid profile?
Answer:
, HDL: Increased
Triglycerides: Decreased
A 73-year-old woman experiences generalized weakness and tingling in her arms and legs. Sensory
examination reveals reduced vibration and proprioception in all extremities. What vitamin deficiency is most
likely?
Answer: Vitamin B12 deficiency (cyanocobalamin)
Common in individuals with a "tea and toast" diet.
A 15-year-old girl presents with a three-month history of acne. What is the underlying cause of her condition?
Answer: Stimulation of sebaceous glands by androgens
Acne: Often associated with Propionibacterium acnes.
A 4-year-old child from Brazil presents with a single 12x10 cm lesion on the right side of the jaw, characterized
by diffuse, regular edges. Photomicrographs from an incisional biopsy resemble the "starry night" pattern seen
in Burkitt's lymphoma. What is the primary process occurring in the indicated region?
Answer: Apoptosis
b. Endemic Burkitt lymphoma can occur in both Brazil and Africa, presenting with jaw lesions and facial
swelling.
A 51-year-old patient with a history of smoking one pack per day for 30 years presents with a 1.5 cm mass on
the apex of the tongue. Which lymph nodes should be evaluated first for metastasis?
Answer: Submental
A 15-year-old boy arrives at the ER with confusion, agitation, fever, headache, stiff neck, and vomiting,
occurring two hours after returning from summer camp. The patient is hallucinating. A lumbar puncture reveals
cysts and trophozoites. What is the most likely pathogen?
Answer: Naegleria fowleri (via the olfactory nerve)
A 17-year-old is brought to the ED 30 minutes after being found staring blankly. Physical examination reveals
rigidity. During the exam, he becomes aggressive and attacks the physician. What drug did the patient most
likely ingest?
Answer: PCP
, A placebo-controlled clinical trial involving 5000 patients with essential hypertension assigns 2500 patients to a
new drug and 2500 to a placebo. If the alpha level is lowered from 0.05 to 0.01, what is the likely outcome?
Answer: Significant findings will be reported with greater confidence.
A 17-year-old gymnast presents with a six-month history of absent menstrual periods. BMI is 15. What is the
most likely cause of her amenorrhea?
Answer: Hypogonadotropic hypogonadism
A male stillborn is delivered at 32 weeks with oligohydramnios and absence of a urethral opening. What is the
most likely associated finding?
Answer: Pulmonary hypoplasia
A 6-day-old breastfed infant presents to the ED with poor weight gain and irritability since birth. Physical
examination reveals jaundice and hepatomegaly. Which metabolite is most likely elevated?
Answer: Galactose-1-phosphate (indicative of congenital galactose intolerance)
A 25-year-old man presents to the ED with severe muscle pain and diffuse painful swelling in his neck, armpits,
and groin after camping in New Mexico. Examination reveals generalized black macules and an erythematous,
tender mass on the right upper extremity, which is draining blood and necrotic material. The most effective
antibiotic for this condition interferes with which process?
Answer: Ribosomal assembly (Yersinia pestis)
A 45-year-old man experiences progressive weakness, upper extremity muscle fasciculations, and lower
extremity weakness. What additional finding is expected?
Answer: Muscle atrophy (suggestive of ALS/Lou Gehrig’s disease)
A new severe respiratory illness is being studied. Why would a killed vaccine be preferred over a live vaccine?
Answer: To prevent the risk of reversion to virulence.
b. Killed vaccines avoid the possibility of causing disease, whereas live vaccines, though rare, may lead to
infection.
A 33-year-old woman is diagnosed with keratinizing squamous cell carcinoma of the cervix. What describes the
pathogenesis of her disease?
Answer: Inactivation of cellular p53 (a tumor suppressor that promotes apoptosis)
A 54-year-old man with a 40-year history of type 1 diabetes is receiving hemodialysis for end-stage renal
disease while awaiting a kidney transplant. He is given a drug that induces reticulocyte release and stimulates a
EXAM QUESTIONS AND 100% CORRECT DETAILED
ANSWERS (USMLE STEP 1) MEDICAL EXAMINATION
A 62-year-old woman is diagnosed with osteoporosis and prescribed a bisphosphonate. What is the expected
beneficial effect of the drug?
Answer: Decreased osteoclast activity
A cohort study of elderly women finds that the relative risk for hip fractures among those who exercise
regularly is 1.2, with a 95% confidence interval of 1.1 to 1.8. What conclusion can be drawn about the effect of
exercise on hip fracture risk?
Answer: Statistically significant overall increased risk
A 52-year-old man presents to the ER with chest pain radiating to his jaw while shoveling snow. His pulse is
80/min, and blood pressure is 130/70. What is the mechanism of action of the most immediate treatment?
Answer: Increased nitric oxide concentration
A 24-year-old woman spills hot grease on her left leg while working at a fast-food restaurant. Examination
reveals a 7 cm pink, soft, granular, edematous wound. The formation of this tissue is most likely due to the
increased activity of which factor?
Answer: Vascular Endothelial Growth Factor (VEGF)
VEGF stimulates angiogenesis.
Type III collagen is involved in early wound repair and blood vessel formation.
A 27-year-old man involved in a motor vehicle collision has a skull X-ray revealing a linear, non-depressed
basal skull fracture. His serum osmolarity is increased, and urine osmolarity is decreased. Following
administration of desmopressin, urine osmolarity increases. The effect of desmopressin is due to activation of
which pathway?
Answer: Adenylyl cyclase (V2 receptor activation)
A 10-month-old boy with a four-day history of fever and cough attends a daycare center. Chest examination
reveals intercostal retractions, bilateral diffuse wheezing, and expiratory rhonchi. What property does the most
likely infectious agent have?
Answer: Mediates cell entry via a fusion protein
,A 17-year-old girl arrives at the ED 15 minutes after being stung by a bee. She reports mild lightheadedness but
has no difficulty swallowing. Bilateral wheezing is noted. What is the most appropriate pharmacologic
treatment?
Answer: Beta-2 agonist
A 14-year-old boy presents with a two-day history of sore throat, fever peaking in the late afternoon, and
fatigue lasting one week. He recently had sexual intercourse with one partner. Physical examination reveals
cervical lymphadenopathy and pharyngeal erythema with a creamy exudate. What is the diagnosis?
Answer: Infectious mononucleosis
A 57-year-old man undergoes radiation therapy for squamous cell carcinoma of the lung. Despite treatment, the
tumor continues to grow, and he dies six months later. The tumor's progression is due to a defect in which phase
of the cell cycle?
Answer: G1 phase
A 28-year-old man who lived in sub-Saharan Africa before moving to the U.S. presents with a temperature of
100.4°F. Imaging reveals bilateral hydroureter and hydronephrosis. Biopsy shows marked fibrosis and scattered
granulomas. What is the most likely diagnosis?
Answer: Schistosomiasis
A couple has a family history of alpha-thalassemia. The woman has a one-gene deletion, and the man has a
two-gene deletion in trans. What percentage of their offspring will inherit a two-gene deletion?
Answer: 50%
A previously healthy 40-year-old woman is brought to the ED by her husband due to a two-day history of fever,
lethargy, and confusion. Physical examination reveals scattered petechiae and ecchymoses on the lower
extremities. Laboratory findings show 3+ polychromasia, 3+ schistocytes, and low platelet count. What is the
most likely diagnosis?
Answer: Thrombotic thrombocytopenic purpura (TTP)
A 16-year-old boy is admitted to the ER after sustaining a knife wound to the left side of his chest. A chest X-
ray reveals an air-fluid level on the left side, partial lung collapse, and an elevated stomach bubble. The
mediastinum remains midline. What is the diagnosis?
Answer: Tension hemopneumothorax
A 49-year-old woman with coronary artery disease has a blood pressure of 140/90, high cholesterol, LDL of
190, and triglycerides of 350. She is prescribed atorvastatin and losartan. What are the expected effects on her
lipid profile?
Answer:
, HDL: Increased
Triglycerides: Decreased
A 73-year-old woman experiences generalized weakness and tingling in her arms and legs. Sensory
examination reveals reduced vibration and proprioception in all extremities. What vitamin deficiency is most
likely?
Answer: Vitamin B12 deficiency (cyanocobalamin)
Common in individuals with a "tea and toast" diet.
A 15-year-old girl presents with a three-month history of acne. What is the underlying cause of her condition?
Answer: Stimulation of sebaceous glands by androgens
Acne: Often associated with Propionibacterium acnes.
A 4-year-old child from Brazil presents with a single 12x10 cm lesion on the right side of the jaw, characterized
by diffuse, regular edges. Photomicrographs from an incisional biopsy resemble the "starry night" pattern seen
in Burkitt's lymphoma. What is the primary process occurring in the indicated region?
Answer: Apoptosis
b. Endemic Burkitt lymphoma can occur in both Brazil and Africa, presenting with jaw lesions and facial
swelling.
A 51-year-old patient with a history of smoking one pack per day for 30 years presents with a 1.5 cm mass on
the apex of the tongue. Which lymph nodes should be evaluated first for metastasis?
Answer: Submental
A 15-year-old boy arrives at the ER with confusion, agitation, fever, headache, stiff neck, and vomiting,
occurring two hours after returning from summer camp. The patient is hallucinating. A lumbar puncture reveals
cysts and trophozoites. What is the most likely pathogen?
Answer: Naegleria fowleri (via the olfactory nerve)
A 17-year-old is brought to the ED 30 minutes after being found staring blankly. Physical examination reveals
rigidity. During the exam, he becomes aggressive and attacks the physician. What drug did the patient most
likely ingest?
Answer: PCP
, A placebo-controlled clinical trial involving 5000 patients with essential hypertension assigns 2500 patients to a
new drug and 2500 to a placebo. If the alpha level is lowered from 0.05 to 0.01, what is the likely outcome?
Answer: Significant findings will be reported with greater confidence.
A 17-year-old gymnast presents with a six-month history of absent menstrual periods. BMI is 15. What is the
most likely cause of her amenorrhea?
Answer: Hypogonadotropic hypogonadism
A male stillborn is delivered at 32 weeks with oligohydramnios and absence of a urethral opening. What is the
most likely associated finding?
Answer: Pulmonary hypoplasia
A 6-day-old breastfed infant presents to the ED with poor weight gain and irritability since birth. Physical
examination reveals jaundice and hepatomegaly. Which metabolite is most likely elevated?
Answer: Galactose-1-phosphate (indicative of congenital galactose intolerance)
A 25-year-old man presents to the ED with severe muscle pain and diffuse painful swelling in his neck, armpits,
and groin after camping in New Mexico. Examination reveals generalized black macules and an erythematous,
tender mass on the right upper extremity, which is draining blood and necrotic material. The most effective
antibiotic for this condition interferes with which process?
Answer: Ribosomal assembly (Yersinia pestis)
A 45-year-old man experiences progressive weakness, upper extremity muscle fasciculations, and lower
extremity weakness. What additional finding is expected?
Answer: Muscle atrophy (suggestive of ALS/Lou Gehrig’s disease)
A new severe respiratory illness is being studied. Why would a killed vaccine be preferred over a live vaccine?
Answer: To prevent the risk of reversion to virulence.
b. Killed vaccines avoid the possibility of causing disease, whereas live vaccines, though rare, may lead to
infection.
A 33-year-old woman is diagnosed with keratinizing squamous cell carcinoma of the cervix. What describes the
pathogenesis of her disease?
Answer: Inactivation of cellular p53 (a tumor suppressor that promotes apoptosis)
A 54-year-old man with a 40-year history of type 1 diabetes is receiving hemodialysis for end-stage renal
disease while awaiting a kidney transplant. He is given a drug that induces reticulocyte release and stimulates a
