Practice Test 2 - USMLE Step 1

20 questions. Answer them in any order, then submit to see your score and every explanation.

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1. The initial event in the pathogenesis of this patient's coronary artery disease is most likely which of the following?
2. Activation of the TSH receptor ultimately leads to increased thyroid hormone synthesis primarily through stimulation of which of the following cellular processes?
3. Under these conditions, which of the following is the most likely outcome?
4. A deficiency in which of the following would most likely explain his recurrent infections with this specific pathogen?
5. This patient's condition is caused by a loss-of-function mutation in a gene whose product directly antagonizes the action of which signaling enzyme?
6. What is the relative risk reduction (RRR) of DVT with the new anticoagulant?
7. A 24-year-old woman with a history of generalized anxiety disorder presents with tremulousness and insomnia that began the day after she stopped taking alprazolam, which she had used at progressively higher doses for 2 years. Exam shows tachycardia, diaphoresis, and marked agitation. Which of the following benzodiazepines is most appropriate for managing her current condition while minimizing the risk of recurrent, severe withdrawal symptoms?
8. Which of the following processes is directly inhibited by the active form of tenofovir?
9. Which of the following additional mechanisms is characteristic of propylthiouracil but not methimazole?
10. This patient's symptoms are characteristic of a deficiency of a vitamin that serves as a precursor for cofactors required by which of the following enzymes?
11. Which of the following best describes the ventilation/perfusion (V/Q) abnormality in the affected lobe that is causing his hypoxemia?
12. Which stain is the standard method for visualizing parasites, such as Plasmodium species, within red blood cells on a blood smear?
13. The patient's neurologic symptoms are most directly related to a decrease in the serum concentration of which of the following?
14. In contrast to bisphosphonates, which are anti-resorptive, teriparatide improves bone density through which of the following mechanisms?
15. A defect in which of the following is the underlying cause of this patient's condition?
16. A 60-year-old man begins BP therapy. Baseline 10-year stroke risk is 10%; treated risk is 8% (ARR 2%). Which statement about the number needed to treat (NNT) is correct?​
17. Which of the following molecules acts as a key allosteric inhibitor of PFK-1, signaling a state of high cellular energy?
18. This patient's condition is most likely caused by a mutation in the gene encoding which of the following proteins?
19. The bactericidal effect of ceftriaxone is due to its ability to inhibit which of the following processes?
20. The AIRE protein plays a critical role in which of the following immunologic processes?

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