Which of these statements explains why the ratio of adenine to thymine is nearly 1: 1 ? a adenine bases contain a form of thymine b adenine and thymine are identical in chemical composition c adenine and thymine pair with each other d adenine binds with phosphates, while thymine binds with nitrates

The correct answer is option (C) adenine and thymine pair with each other .

DNA is the genetic material of all the organisms, excpet a few viruses. It is made up of the four nitrogenous bases called the adenine, guanine, cytosine and thymine. Adenine and guanine form the purines and the cytosine and thymine form the pyrimidines. According to Chargaff's rule of base equivalence, a purine can pair only with a pyrimidine or vice-versa or it states that the DNA from any cell of any organism should have a 1:1 ratio of pyrimidine and purine bases. The amount of adenine is equal to the amount of thymine and the amount of guanine is equal to the amount of cytosine as adenine always pairs with thymine and guanine always pairs with the cytosine. Thus, the ratio of adenine to thymine is 1:1.

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