W2L3 - DNA MCQ

• What base is not found in the DNA?

  uracil
• How many base pairs are there in one full turn of the DNA double helix in its B form?

  • 10
  • 14
  • 16
  • 2
  • 4

  10
• The three major forms of the DNA double helix are A, B and Z form. Which is considered the normal form in the cell?


  B
• Which technique was used to determine the double-helical structure of DNA?

  • X-ray crystallography
  • centrifugation
  • chromatography
  • electrophoresis

  X-ray crystallography
• The double-helical structure of DNA is formed by which forces?

  1. a combination of hydrogen bonds and stacking interactions
  2. covalent bonds
  3. hydrogen bonds between the bases
  4. stacking interactions between the bases
  5. van der Waals interactions

  1
• DNA from any cell of any organism should have a 1:1 ratio of _______ and _______ bases (Chargaff's rule)

  1. adenine, thymidine
  2. cytosine, guanine
  3. phosphate, sugar
  4. pyrimidine, purine
  5. ribose, base

  4
• If 30% of the bases in a given DNA molecule are adenine. What is the correct percentage of guanine bases in the DNA molecule?

  1. 10%
  2. 20%
  3. 30%
  4. 40%

  2
• Which of the following pairs are purines?

  1. adenine and guanine
  2. adenine and thymidine
  3. cytosine and guanine
  4. cytosine and thymidine

  1
• The distance between a single base pair in B DNA is?

  1. 2 nm
  2. 34 nm
  3. 3.4 nm
  4. 4 μm
  5. 4 nm

  3