In a double-stranded DNA molecule 15 percent of the bases are adenine. What percentage are guanine?
Answer and explanation
Correct answer: A. 35%
- Step 1: A pairs with T, so thymine is also 15%.
- Step 2: A + T = 30%; the remaining 70% is G + C, shared equally, so G = 35%.
Answer
35%.
Why not the others: 15%: guanine was assumed to be as common as adenine. 70%: this is the combined percentage of guanine and cytosine. 65%: the percentages were added.
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