USMLE Step 1: Question 101 (with answer and explanation)

he USMLE Content Outline organizes content according to general principles and individual organ systems. Test questions are classified in one of 18 major areas, depending on whether they focus on concepts and principles that are important across organ systems or within individual organ systems. Sections focusing on individual organ systems are subdivided according to normal and abnormal processes, including principles of therapy.

Each Step 1 examination covers content related to the following traditionally defined disciplines:

  • anatomy
  • behavioral sciences
  • biochemistry
  • biostatistics and epidemiology
  • microbiology
  • pathology
  • pharmacology
  • physiology
    The Step 1 examination also covers content related to the following interdisciplinary areas:
  • genetics
  • aging
  • immunology
  • nutrition
  • molecular and cell biology