18
35.
A 10-month-old boy is brought to the physician because of a 4-day history of fever and cough. His illness began with low-
grade fever and copious, clear nasal discharge. Two days ago he developed a moist, nonproductive cough and rapid
breathing. He has received all scheduled childhood immunizations. He attends a large day-care center and has three school-
aged siblings. His temperature is 38°C (100.4°F), pulse is 101/min, respirations are 38/min, and blood pressure is
85/60 mm Hg. Physical examination shows nasal flaring and rhinorrhea. Chest examination shows intercostal retractions
along with bilateral, diffuse wheezes and expiratory rhonchi. The infectious agent of this patient's condition most likely has
which of the following properties?
(A) DNA genome
(B) Double-stranded nucleic acid genome
(C) Mature virion lacking viral polymerase
(D) Mediation of cell entry via a fusion protein
(E) Viability on surfaces for several weeks
36.
A 17-year-old girl is brought to the emergency department 15 minutes after being stung by a bee. She has mild light-
headedness but no difficulty swallowing. Her temperature is 37.1°C (98.8°F), pulse is 100/min, respirations are 30/min, and
blood pressure is 115/70 mm Hg. Physical examination shows no urticaria. Bilateral wheezing is heard on auscultation of the
chest. Which of the following types of drugs is the most appropriate pharmacotherapy for this patient?
(A) α
1
-Adrenergic agonist
(B) α
2
-Adrenergic agonist
(C) α
1
-Adrenergic antagonist
(D) β
2
-Adrenergic agonist
(E) β
2
-Adrenergic antagonist
37.
A 30-year-old woman, gravida 2, para 0, aborta 1, at 28 weeks' gestation comes to the office for a prenatal visit. She has had
one previous pregnancy resulting in a spontaneous abortion at 12 weeks' gestation. Today, her vital signs are within normal
limits. Physical examination shows a uterus consistent in size with a 28-week gestation. Fetal ultrasonography shows a male
fetus with no abnormalities. Her blood group is O, Rh-negative. The father's blood group is B, Rh-positive. The physician
recommends administration of Rh
o
(D) immune globulin to the patient. This treatment is most likely to prevent which of the
following in this mother?
(A) Development of natural killer cells
(B) Development of polycythemia
(C) Formation of antibodies to RhD
(D) Generation of IgM antibodies from fixing complement in the fetus
(E) Immunosuppression caused by RhD on erythrocytes from the fetus
38.
A 52-year-old woman begins pharmacotherapy after being diagnosed with type 2 diabetes mellitus. Four weeks later, her
hepatic glucose output is decreased, and target tissue glucose uptake and utilization are increased. Which of the following
drugs was most likely prescribed for this patient?
(A) Acarbose
(B) Glyburide
(C) Metformin
(D) Nateglinide
(E) Repaglinide
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39.
A sexually active 23-year-old man with multiple sex partners has dysuria and a yellow urethral exudate. Gram stain of the
exudate shows numerous neutrophils, many that contain intracellular gram-negative diplococci. He has had three similar
episodes of urethritis over the past 2 years. Which of the following properties of the infecting organism best explains the
reinfection?
(A) Antigenic variation
(B) Catalase
(C) Inhibition of B-lymphocyte function
(D) Inhibition of T-lymphocyte function
(E) Polysaccharide capsule
40.
A 17-year-old girl is brought to the physician by her mother because she has not had a menstrual period for 6 months. The
patient is unconcerned about the lack of menses. Menarche occurred at the age of 12 years, and menses had occurred at
regular 28-day intervals until they became irregular 1 year ago. She is a member of her high school gymnastics team. She
appears emaciated. She is 163 cm (5 ft 4 in) tall and weighs 40 kg (88 lb); BMI is 15 kg/m
2
. Her pulse is 54/min, and blood
pressure is 80/50 mm Hg. Which of the following is the most likely cause of this patient's amenorrhea?
(A) Hyperthyroidism
(B) Hypogonadotropic hypogonadism
(C) Hypothyroidism
(D) Polycystic ovarian syndrome
(E) Prolactinoma
20
USMLE STEP 1 SAMPLE TEST QUESTIONS
BLOCK 2, ITEMS 41-80
41.
A 49-year-old woman comes to the physician for a follow-up examination. She has a strong family history of coronary artery
disease. Her blood pressure has ranged from 150/95 mm Hg to 130/85 mm Hg during the previous three visits within the past
2 months. Her blood pressure today is 140/90 mm Hg. Physical examination shows no other abnormalities. Laboratory
studies show:
Cholesterol, total
290 mg/dL
HDL-cholesterol
40 mg/dL
LDL-cholesterol
190 mg/dL
Triglycerides
350 mg/dL
Treatment with atorvastatin and losartan is initiated. Which of the following serum findings is most likely to occur in this
patient?
HDL-cholesterol
Triglycerides
(A)
Decreased
decreased
(B)
Decreased
increased
(C)
Increased
decreased
(D)
Increased
increased
(E)
No change
no change
42.
A 15-year-old girl comes to the physician because of a 3-month history of acne. Breast and pubic hair development began at
the age of 12 years. Menarche occurred at the age of 14 years. Physical examination shows scattered open and closed
comedones over the cheeks and forehead. Breast and pubic hair development are Tanner stage 5. Which of the following is
the most likely underlying cause of this patient's acne?
(A) Decreased parasympathetic stimulation to the sebaceous glands
(B) Increased estrogen stimulation of the sebaceous glands
(C) Increased responsiveness of the sebaceous glands to follicle-stimulating hormone
(D) Increased sympathetic stimulation to the sebaceous glands
(E) Stimulation of the sebaceous glands by androgens
43.
A previously healthy 40-year-old man is brought to the emergency department because of constant substernal chest pain for
12 hours that is exacerbated by coughing and inspiration. The pain is relieved with sitting up and leaning forward. There is no
family history of heart disease. His temperature is 38°C (100.4°F), pulse is 120/min, and blood pressure is 110/60 mm Hg.
The lungs are clear to auscultation. Cardiac examination shows distant heart sounds. An ECG shows diffuse ST-segment
elevation in all leads. An x-ray of the chest shows normal findings. The most likely cause of his condition is injury to which
of the following tissues?
(A) Aortic intima
(B) Esophageal sphincter
(C) Myocardium
(D) Pericardium
(E) Pleura