Repeated USMLE Questions Step 1- 372

Q- A study found that incidence of lung cancer in smokers is 230/100,000 and in non-smokers is 71/100,000. What is the relative risk for smokers?

A-2.3

B- 3.2

C- 71

D- 230

B- 3.2- Relative risk is reached by dividing the smokers’ group by the non-smokers’.

Q- A patient with cystic fibrosis is treated by gene therapy. Which of the following types of cells should be targeted as host cells?

A- Epithelial cells

B- Hemopoietic stem cells

C- Germ cells

D- T-cells

A- Epithelial cells- Chloride transport is defected in these cells.

Q- Which of the following should be added to premature infants of breast-feeding mothers after 2 month of age?

A- Copper

B- Iron

C- Vitamin C

D- Zink

B- Iron- It should be added after 2 months while vitamin C can be added after 3-6 months.