12 USMLE Step 1 Mixed Review Questions with Answers (Set 10)

These 12 quick USMLE review questions test high-yield facts that show up again and again on the exam: diabetes in pregnancy, leukemia CNS prophylaxis, the Hawthorne effect, syphilis, fifth disease, UTI, vaccine refusal, chronic kidney disease, porphyria cutanea tarda, Rocky Mountain spotted fever, fat embolism and osteoarthritis. Each question includes the correct answer.

Written by Dr. Ray Makar, MD, author of the Repeated USMLE Questions eBook series.

Prefer video? Watch daily USMLE case questions on MedFocus by Dr. Ray on YouTube.

How to use this page: read the question, pick your answer, then tap Show Answer and Explanation.

Questions

Question 1. A 30-year-old pregnant woman visits her obstetrician’s clinic at 10 weeks of gestation. The patient has a history of type 1 diabetes and is worried that her condition may cause some complications in her pregnancy. From the list below, advise your patient that all of the following are a potential risk of type 1 diabetes in pregnancy EXCEPT which one?

A- Fetal malformations
B- Neonatal hyperglycemia
C- Preterm labor
D- Spontaneous abortions in the first trimester

B- Neonatal hyperglycemia- Babies of diabetic mothers develop neonatal HYPOglycemia after birth, because their own insulin production stays high once the maternal glucose supply is cut off. Poorly controlled type 1 diabetes in pregnancy raises the risk of congenital malformations (especially heart and neural tube defects, caudal regression), first-trimester miscarriage, preterm labor, preeclampsia, macrosomia and cesarean delivery.
The correct answer is B

 

Question 2. Which one of the following treatments most likely prevents meningeal leukemia in a young boy diagnosed with acute lymphoblastic leukemia?

A- Cyclophosphamide
B- High dose of cortisone
C- Intrathecal methotrexate
D- Radiotherapy

C- Intrathecal methotrexate- Acute lymphoblastic leukemia often causes meningeal leukemia when relapse occurs. Intrathecal methotrexate is the only one on the list prevents meningeal leukemia during if relapse occurs.
The correct answer is C

 

Question 3. A group of people is assigned for a research study about the effect of a new hypoglycemia medication. Because they are aware of the study, they eat less carbohydrate. Which type of bias is involved in this study?

A- Confounding bias
B- Hawthorne effect
C- Information bias
D- Sample distortion bias

B- Hawthorne effect- This bias will affect the outcome of the study because are aware of it. This bias can be avoided by keeping them unaware of the study. “Blind study”.
The correct answer is B

 

Question 4. Which of the following conditions is characterized by the presence of smooth, painless, wart-like lesions on genital organs?

A- Candida infection
B- Chlamydia infection
C- Gonococcal infection
D- Secondary syphilis

D- Secondary syphilis- These are condyloma lata and are found in secondary syphilis.
The correct answer is D

 

Question 5. Erythema infectiosum (Fifth disease) is caused by which of the following organisms?

A- Coxsackie A virus
B- Paramyxovirus
C- Parvovirus B19
D- Rubella virus

C- Parvovirus B19- This disease is characterized by “slapped-check” erythematous rash and rashes on the arms, trunk and legs that worsen with fever, hot weather and exposure to sun.
The correct answer is C

 

Question 6. A 32-year-old woman presents with burning micturition, frequency, and pain in the suprapubic region. There is no fever, vaginal discharge, or pruritus. She had no similar episodes, and she has not taken any medications. Which of the following is the most likely causative organism of this condition?

A- Campylobacter
B- Escherichia coli
C- Staphylococcus aureus
D- Streptococcus viridians

B- Escherichia coli- This is most likely a case of uncomplicated lower urinary tract infection. 75%-95% of cases are caused by E. coli. A- Food poisoning C and D causes a lot of other infections, but E. coli is the most common in UTI.
The correct answer is B

 

Question 7. When you suggested to a mother to vaccinate her child with MMR on a scheduled basis, she refused for religious reasons. What is the most appropriate next step?

A- Explain to her with documentation the benefits and risks of immunization
B- Obtain a court order
C- Proceed with immunization
D- Report her to the health authorities

A- Explain to her with documentation the benefits and risks of immunization- Unfortunately, the parents still have the right to refuse immunization for their children but it is necessary to keep documentation in case of future problems.
The correct answer is A

 

Question 8. Which of the following findings distinguishes chronic renal failure from acute renal failure?

A- High serum calcium
B- High serum sodium
C- History of elevated BUN
D- History of elevated serum creatinine

D- History of elevated serum creatinine- A, B and C may occur in both acute and chronic renal failure but creatinine is specific for chronic renal failure
The correct answer is D

 

Question 9. Which one of the following conditions is characterized by painless blisters on the back of the hands and hyperpigmentation of the face?

A- Contact dermatitis
B- Dermatitis herpetiformis
C- Herpes zoster
D- Porphyria cutanea tarda

D- Porphyria cutanea tarda- it is due deficiency of uroporphyrinogen decarboxylase enzyme leading to skin fragility and facial hyperpigmentation.
The correct answer is D

 

Question 10. Which of the following is the vector responsible for the transmission of Rocky Mountain spotted fever?

A- Flea
B- Louse
C- Mite
D- Tick

D- Tick
The correct answer is D

 

Question 11. Which one of the following is a fatal complication of multiple long bone fractures in a young age?

A- Deep venous thrombosis
B- Fat embolism
C- Pericardial effusion
D- Thromboembolism

B- Fat embolism- It is rare but unpredictable. It can lead to sudden death in a young patient. Thrombosis and its complication are excluded because the patient is young.
The correct answer is B

 

Question 12. Which of the following joint conditions is characterized by narrowing of the joint space and formation of osteophytes?

A- Gouty arthritis
B- Osteoarthritis
C- Pseudogout
D- Rheumatoid arthritis

B- Osteoarthritis
The correct answer is B

 

High-yield points from this set

  • Infants of diabetic mothers develop neonatal hypoglycemia.
  • Parvovirus B19 causes fifth disease (“slapped cheek”).
  • Ticks transmit Rocky Mountain spotted fever.
  • Osteoarthritis causes joint space narrowing with osteophytes.

Keep practicing

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