Assume a certain molecule of DNA is composed of exactly 22 percent adenine.How much cytosine would you expect to find in this molecule?

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Quizplus · Accepted Answer

According to Chargaff's rule, the percentage of adenine (A) in DNA is always equivalent to the percentage of thymine (T), and the percentage of cytosine (C) is always equivalent to the percentage of guanine (G). Therefore, if the DNA molecule is composed of 22 percent adenine, it must also contain 22 percent thymine. The remaining 56 percent must be split equally between cytosine and guanine, meaning that the percentage of cytosine would be 28 percent (56 percent divided by 2). Thus, the correct choice is B.

Assume a Certain Molecule of DNA Is Composed of Exactly