Final answer:
Given 22% guanine in a double-stranded DNA molecule, there will also be 22% cytosine. The remaining 56% of the bases are divided equally between adenine and thymine, each with 28%.
Step-by-step explanation:
The subject here is the base pairing in a double-stranded DNA molecule. According to Chargaff's rules, in DNA, the amount of adenine (A) is equal to the amount of thymine (T), and the amount of guanine (G) is equal to the amount of cytosine (C). This is because A:T and G:C are the base pairs in DNA. Therefore, if a double-stranded DNA molecule has 22% guanine, it will also have 22% cytosine, as guanine only pairs with cytosine. Moreover, the remaining 56% of the bases will be equally divided between adenine and thymine, giving each 28%. Therefore, the correct answer is 22% cytosine.
Learn more about DNA base pairing