NBME CBSE AND USMLE STEP 1
PRACTICE EXAM QUESTIONS AND
ANSWERS
1. A 24-year-old male presents with a painless, hard mass in his right testicle. Lab results
show elevated alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG). What is the
most likely diagnosis?
A. Seminoma
B. Yolk sac tumor
C. Leydig cell tumor
D. Embryonal carcinoma
Answer: D
Conceptual Explanation: Embryonal carcinoma is an aggressive non-seminomatous germ
cell tumor that often presents with elevated hCG and AFP when mixed components are
present. Pure seminomas usually have normal AFP.
2. A 45-year-old female with a history of systemic lupus erythematosus (SLE) presents with
swelling of the legs. Urinalysis reveals 4+ protein and ‘fatty casts.’ What is the most likely
glomerular pathology?
A. Minimal change disease
,B. Focal segmental glomerulosclerosis
C. Diffuse proliferative glomerulonephritis
D. Membranous nephropathy
Answer: D
Conceptual Explanation: Membranous nephropathy is the most common cause of
nephrotic syndrome in adults with SLE, characterized by subepithelial deposits and ‘spike
and dome’ appearance.
3. Which of the following biochemical changes occurs in a patient during the first 24 hours of
fasting?
A. Increased muscle protein breakdown
B. Inhibition of hormone-sensitive lipase
C. Ketone body production as the primary fuel for the brain
D. Depletion of hepatic glycogen stores
Answer: D
Conceptual Explanation: In the early stages of fasting (12-24 hours), hepatic
glycogenolysis is the primary source of blood glucose. Glycogen stores are typically
depleted after 24 hours.
, 4. A 60-year-old man presents with sudden-onset tearing chest pain radiating to the back. His
blood pressure is 180/110 mmHg. What is the most significant risk factor for this condition?
A. Diabetes mellitus
B. Hyperlipidemia
C. Hypertension
D. Bicuspid aortic valve
Answer: C
Conceptual Explanation: Hypertension is the most common and significant risk factor for
aortic dissection, leading to cystic medial degeneration.
5. A patient is diagnosed with Megaloblastic Anemia. Labs show elevated homocysteine but
normal methylmalonic acid. What is the deficiency?
A. Vitamin B12
B. Vitamin B6
C. Iron
D. Folate
Answer: D
Conceptual Explanation: Folate deficiency leads to increased homocysteine but normal
methylmalonic acid levels, whereas B12 deficiency increases both.
PRACTICE EXAM QUESTIONS AND
ANSWERS
1. A 24-year-old male presents with a painless, hard mass in his right testicle. Lab results
show elevated alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG). What is the
most likely diagnosis?
A. Seminoma
B. Yolk sac tumor
C. Leydig cell tumor
D. Embryonal carcinoma
Answer: D
Conceptual Explanation: Embryonal carcinoma is an aggressive non-seminomatous germ
cell tumor that often presents with elevated hCG and AFP when mixed components are
present. Pure seminomas usually have normal AFP.
2. A 45-year-old female with a history of systemic lupus erythematosus (SLE) presents with
swelling of the legs. Urinalysis reveals 4+ protein and ‘fatty casts.’ What is the most likely
glomerular pathology?
A. Minimal change disease
,B. Focal segmental glomerulosclerosis
C. Diffuse proliferative glomerulonephritis
D. Membranous nephropathy
Answer: D
Conceptual Explanation: Membranous nephropathy is the most common cause of
nephrotic syndrome in adults with SLE, characterized by subepithelial deposits and ‘spike
and dome’ appearance.
3. Which of the following biochemical changes occurs in a patient during the first 24 hours of
fasting?
A. Increased muscle protein breakdown
B. Inhibition of hormone-sensitive lipase
C. Ketone body production as the primary fuel for the brain
D. Depletion of hepatic glycogen stores
Answer: D
Conceptual Explanation: In the early stages of fasting (12-24 hours), hepatic
glycogenolysis is the primary source of blood glucose. Glycogen stores are typically
depleted after 24 hours.
, 4. A 60-year-old man presents with sudden-onset tearing chest pain radiating to the back. His
blood pressure is 180/110 mmHg. What is the most significant risk factor for this condition?
A. Diabetes mellitus
B. Hyperlipidemia
C. Hypertension
D. Bicuspid aortic valve
Answer: C
Conceptual Explanation: Hypertension is the most common and significant risk factor for
aortic dissection, leading to cystic medial degeneration.
5. A patient is diagnosed with Megaloblastic Anemia. Labs show elevated homocysteine but
normal methylmalonic acid. What is the deficiency?
A. Vitamin B12
B. Vitamin B6
C. Iron
D. Folate
Answer: D
Conceptual Explanation: Folate deficiency leads to increased homocysteine but normal
methylmalonic acid levels, whereas B12 deficiency increases both.
