4. A 43-year-old man is evaluated for progressive neuropsychiatric symptoms. A year ago, he began feeling depressed and having hallucinations. Five months later, he developed intermittent paresthesias and progressively worsening choreiform movements, myoclonus, and ataxia. These symptoms have not improved despite multiple hospitalizations; an extensive workup has been unrevealing. The patient is a slaughterhouse worker with extensive exposure to bovine offal. As part of the evaluation for prion disease, a tissue sample lysate is processed via gel electrophoresis and transferred to filter paper. Antibodies to a specific prion protein are added to the filter. Next, a marked protein that combines with the antibody-protein complex is used to determine whether the test is positive. Which of the following best describes this test?
A. Microarray
B. Northern blot
C. Southern blot
D. Southwestern blot
E. Western blot
5. A healthy 34-year-old coal mine worker is trapped underground following partial collapse of an access shaft. Rescue efforts are directed toward clearing the obstructed tunnel, but it takes 2 days to reach him. While being taken to the surface, the miner tells rescuers that he feels dizzy and weak. He had an emergency supply of water but has not eaten anything for over 30 hours. Fingerstick blood glucose concentration is 78 mg/dl. Which of the following biochemical reactions is most likely responsible for maintaining this patient’s current blood glucose levels?
A. Acetoacetyl CoA → 3-hydroxy-3-methylglutaryl-CoA
B. Acetyl CoA → palmitic acid
C. Fructose 6-phosphate → fructose 1,6-bisphosphate
D. Glycogen → glucose-1-phosphate
E. Oxaloacetate → phosphoenolpyruvate
6. A man and woman come to the clinic for preconception counseling. The woman and her parents are healthy, but she has 2 siblings with a rare autosomal recessive disease. The woman’s genotype is unknown. The man is also healthy and has no family history of the disease. It is known that, among healthy individuals in the general population, the carrier frequency is 1 in 200. What is the probability of this couple conceiving a child with the disease?
A. 1/200
B. 1/400
C. 1/800
D. 1/1,200
E. 1/1,600