Molecular Biology/Genetics USMLE Step 1 Practice Questions
58 board-style USMLE Step 1 questions in Biochemistry. Each question shows the correct answer; create a free account for the full explanation and adaptive practice.
- USMLE Step 1 · medium49. A 24-year-old female with phenylketonuria (PKU) gives birth to her first child. Although there is no history of PKU in the father's family, the couple could not afford genetic t…
- USMLE Step 1 · medium50. A 12-year-old male has a particular genetic disease. His mother is a carrier of the mutated gene, but his father is not clinically affected and is not a carrier. The patient has…
- USMLE Step 1 · medium51. A 28-year-old molecular biology researcher identifies a novel gene with a conserved 7-helix transmembrane domain motif in a patient with familial hypercholesterolemia. Laborator…
- USMLE Step 1 · medium52. A 32-year-old pregnant woman at 28 weeks gestation is concerned about her female fetus inheriting glucose-6-phosphate dehydrogenase (G6PD) deficiency. Her 6-year-old son has the…
- USMLE Step 1 · medium53. Genomic DNA from a child with pyruvate kinase deficiency identifies a mutation in the 3'-splice site of intron 3. The mRNA from the child's reticulocytes is used to produce cDNA…
- USMLE Step 1 · medium54. A prokaryotic operon codes for 2 enzymes and 1 regulatory protein. The operon is expressed only in the presence of a particular sugar. Initial mapping of the operon has differen…
- USMLE Step 1 · medium55. A 17-year-old high-school student comes to the school health clinic. She has missed her last menstrual period and is worried about being pregnant. In the past history, it is not…
- USMLE Step 1 · medium56. A 23-year-old White female with cystic fibrosis (FEV₁ 65% predicted, pancreatic insufficiency on enzyme replacement therapy) presents with her first cousin to discuss reproducti…
- USMLE Step 1 · medium57. A 45-year-old male with a confirmed diagnosis of hemochromatosis tests negative for the 2 most common mutations in the HFE gene known to cause this disease. The patient and seve…
- USMLE Step 1 · medium58. A 35-year-old female and her husband seek genetic counseling before attempting to conceive. The patient suffers from a particular condition and wants to know the chances that he…