Sample questions / Multisystem & General Principles

Organ system

Multisystem & General Principles questions for Step 1

Work through multisystem & general principles vignettes that mix physiology, pathology and pharmacology, the way the exam does. Every explanation covers all five options.

GeneticsEasy

Beckwith-Wiedemann imprinting

A 4.8-kg newborn (>97th percentile) has a large tongue, an omphalocele, overgrowth of the left leg and enlarged organs, and needs IV dextrose for hypoglycemia. At 3 months, ultrasound shows enlarged kidneys on both sides. Testing shows loss of maternal methylation at IC2 on 11p15.5, with IGF2 expressed from both alleles.

Which genetic mechanism explains his condition?

1. Trinucleotide repeat expansion
2. Genomic imprinting abnormality
3. Mitochondrial mutation
4. X-linked recessive inheritance
5. Chromosomal translocation

MicrobiologyEasy

Germ tube test

Blood cultures from a 29-year-old patient grow yeast. The lab needs to rapidly distinguish Candida albicans from other Candida species.

Which test is fastest?

1. CHROMagar Candida
2. Cornmeal agar morphology
3. Germ tube test
4. Urease test
5. API 20C AUX

ImmunologyMedium

TAP deficiency

A 28-year-old man has recurrent HSV infections with normal immunoglobulins and vaccine titers. CD8 T-cell and NK killing are impaired, and he has a homozygous loss-of-function TAP1 mutation.

Which process is primarily impaired?

1. Cytokine receptor signaling
2. MHC class II expression on APCs
3. Peptide loading onto MHC class I
4. T cell receptor gene rearrangement
5. Immunoglobulin class switching

BiochemistryMedium

Mediator and Pol II CTD

Researchers map contacts in the preinitiation complex and find that Mediator, which links enhancer-bound transcription factors to the basal machinery, mainly contacts one region of RNA polymerase II.

Which domain of RNA polymerase II is Mediator's main partner?

1. The trigger loop that controls nucleotide addition specificity
2. The RNA exit channel where nascent transcript emerges
3. The DNA entry cleft that guides template DNA into the active site
4. The C-terminal domain (CTD) of the largest subunit (Rpb1)
5. The active site catalytic center containing conserved metal ions

PharmacologyEasy

Vancomycin infusion reaction

Thirty minutes into a first vancomycin infusion, a man develops flushing of face and upper trunk, pruritus and mild hypotension, without airway symptoms; tryptase is normal.

What is the best next step?

1. Permanently discontinue vancomycin and switch to linezolid
2. Resume vancomycin at the same rate with close monitoring
3. Administer intramuscular epinephrine immediately
4. Slow the infusion rate and premedicate with diphenhydramine
5. Obtain IgE-specific testing for vancomycin before re-challenge

Other systems

Cardiovascular · Respiratory · Renal & Urinary · Gastrointestinal & Hepatobiliary · Nervous System · Endocrine · Reproductive · Hematology & Oncology · Musculoskeletal & Skin · Behavioral Health ·