Question

In a DNA molecule, the adenine is $15\%$. What will be the percentage of guanine in this DNA?

• A. 0.15
• B. 0.35
• C. 0.7
• D. 0.3

Answer 1

Answer: (B)

0.35

Answer 2

According to Chargaffs rule, the total amount of adenine released is equal to the total amount of thymine and the total amount of cytosine is equal to the total amount of guanine, ie, $A = T$ and $C = G$. Thus, if DNA molecule contains $15\%$ adenine then $C$ and $G$ will constitute $70\%$, out of which guanine will be $35\%$.