2. Many human genes encode more than one polypeptide sequence. Which of the following mechanisms accounts for the production of more than one protein by one human gene in most cases? A
) Alternative splicing of the transcript B i got this wrong, was between a and b for me
) Production of a polycistronic mRNA C
) Reading mRNA in both directions D
) Reading mRNA in more than one reading frame E
) Transcription of both strands of the gene Your answer is indicated by the filled-in circle.
8. Two children in a family have a disease characterized by mental ******ation and mild dysmorphic features. The family was evaluated by standard karyotype and then by DNA microsatellite polymorphism studies for two autosomal markers. A pedigree is shown. Which of the following is the most likely cause of the congenital disorder? A
) Anticipation B
) Autosomal recessive inheritance C
) Genomic imprinting D
) Mitochondrial inheritance
13. An HIV virus has been isolated that is not inhibited by soluble CD4. Mutations are most likely to have occurred in the viral gene encoding which of the following? A
) Core B
) Glycoprotein C
) Integrase D
) Matrix E
) Reverse transcriptase Your answer is indicated by the filled-in circle.
45. A 35-year-old woman with primary pulmonary hypertension undergoes an uncomplicated right lung transplantation. One month later, her FEV
1 is normal, and an exercise stress test shows no abnormalities. Which of the following is most likely to be increased in the transplanted lung compared with the left lung? A
) Airway resistance B
) Blood flow C
) Cough reflex D
) Lung compliance E
) Mucociliary clearance F
) Vascular resistance Your answer is indicated by the filled-in circle.
49. A newborn who has not yet been fed is having respiratory distress. The abdomen is relatively flat, and there are no breath sounds over the thorax on the left. Frontal and lateral plain x-rays of the chest show a shift to the right of the mediastinal structures and opacification of the left hemithorax except for several sausage-shaped air collections posteriorly and inferiorly; the right lung is aerated normally. Which of the following abnormalities is most likely? A
) Absence of the pericardium B
) Posterolateral hernia of the left hemidiaphragm C
) Pulmonary sequestration in the left lower lobe D
) Retrosternal hernia E
) Tracheoesophageal fistula Your answer is indicated by the filled-in circle.
An investigator is evaluating the outcome of coronary artery bypass grafting conducted by two surgeons in the community in the past year. Surgeon X, who operates exclusively at a tertiary-care facility, has a 30-day operative mortality of 3%. Surgeon Y, who operates exclusively at a community care facility, has a 30-day operative mortality of 1%. The difference in operative mortality between surgeon X and surgeon Y is significant (
p<0.05). The investigator concludes that patients should have care at the community care facility. Which of the following raises the most concern regarding the validity of this conclusion? A
) Lack of control of case complexity B
) Lack of control of patient cholesterol data C
) Lack of control of patient follow-up D
) Lack of control of patient recuperation E
) Unequal sample sizes between surgeons Your answer is indicated by the filled-in circle.
A 22-year-old woman participates in a clinical study of a putative protein hormone that is synthesized in the liver in response to a decrease in the blood platelet concentration. Injection of the hormone causes an increase in platelet production. Which of the following is the most likely location of the receptor that accounts for the increase in platelet count? A
) In the cytoplasm of hepatocytes B
) In the cytoplasm of megakaryocytes C
) In the nucleus of hepatocytes D
) In the nucleus of megakaryocytes E
) On the cell membrane of hepatocytes F
) On the cell membrane of megakaryocytes Your answer is indicated by the filled-in circle.
Solution
44. Treatment of respiratory syncytial virus with 70% ethanol destroys its infectivity. The loss of infectivity is the result of a direct effect of the treatment on which of the following viral functions? A
) Entry of the nucleocapsid into the nucleus B
) Fusion of the virion membrane with the target cell membrane C i think it was this one
) Replication of the virus genome D
) Transcription of mRNA Your answer is indicated by the filled-in circle.
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19. A 20-year-old woman comes to the physician for an examination prior to participating on the college varsity volleyball team. She has a 1-month history of mild facial acne. Physical examination shows no other abnormalities. Treatment with a topical agent is begun. Three weeks later, she returns to the physician because of leg swelling and weight gain. Physical examination shows severe facial acne and acne on the chest and back. There is 2+ pitting edema of the lower extremities. Laboratory studies show a mildly increased serum direct bilirubin concentration and serum transaminase activities. The most likely cause of her condition is self-administration of which of the following substances? A
) ACTH B
) Ethinyl estradiol C
) Growth hormone D
) Hydrocortisone E
)
Methandrostenolone Your answer is indicated by the filled-in circle.
49. A 48-year-old man comes to the physician with his wife because of a 10-month history of headache and daytime sleepiness. His wife says that he snores at night and often stops breathing while sleeping. He has no history of any major medical illness and takes no medications. He is 173 cm (5 ft 8 in) tall and weighs 115 kg (253 lb); BMI is 39 kg/m
2. His blood pressure is 150/110 mm Hg. Physical examination shows no other abnormalities. Overnight polysomnography confirms the diagnosis. Nocturnal treatment with nasal bi-level positive airway pressure is most appropriate for this patient to accomplish which of the following? A
) Allowing the airway to remain patent for appropriate ventilation B
) Decreasing the work of breathing during the respiratory cycle C
) Reducing airway secretions during the ventilatory cycle D
) Stimulating increased lung compliance on inspiration and decreased lung compliance on expiration E
) Stimulating increased respirations by splinting the mouth and nose Your answer is indicated by the filled-in circle.
Your answer is indicated by the filled-in circle.
