Question

In a DNA double helix, where are the nitrogenous bases located?

Options

• They face outward from the helical axis

• They face inward toward each other and pair via hydrogen bonds

• They are randomly distributed throughout the structure

• They are located on the exterior of the double helix

Answer 1

In a DNA double helix, the nitrogenous bases are located in the interior of the helix, facing inward toward each other. The complementary bases form hydrogen bonds between them (A with T, G with C), while the sugar-phosphate backbone faces outward.