MDCAT Biology MCQ #898

An X-ray diffraction study of the DNA molecule reveals a repeating pattern in the double helix. What is the standard diameter of the DNA molecule?

MDCAT Biology MCQ #898

  1. Question 1

    Q1. An X-ray diffraction study of the DNA molecule reveals a repeating pattern in the double helix. What is the standard diameter of the DNA molecule?

    • A) 2 nm
    • B) 3.4 nm
    • C) 0.34 nm
    • D) 20 nm

    Answer: 2 nm

    Explanation: DNA diameter is 2nm; 3.4nm is the distance of one complete turn of the helix, which is a common distractor.