An organism's genome is analyzed and found to contain 18% thymine. What percentage of that organism's DNA is cytosine?
A)32%
B)18%
C)82%
D)64%
E)36%

Question

Quizplus · Accepted Answer

Thymine always pairs with adenine, and cytosine always pairs with guanine. Therefore, the percentage of cytosine in the DNA must be equal to the percentage of guanine, which is 100% - 18% (thymine) - 18% (adenine) = 64%.

An Organism's Genome Is Analyzed and Found to Contain 18