MDCAT Biology MCQ #878

A sample of double-stranded DNA is analyzed and found to contain 20% Cytosine. What is the expected percentage of Adenine in this sample?

MDCAT Biology MCQ #878

  1. Question 1

    Q1. A sample of double-stranded DNA is analyzed and found to contain 20% Cytosine. What is the expected percentage of Adenine in this sample?

    • A) 20%
    • B) 40%
    • C) 25%
    • D) 30%

    Answer: 30%

    Explanation: Chargaff's rule (A=T, G=C) implies if C=20%, then G=20%. The remaining 60% is shared equally between A and T (30% each).