Question

Adenine of DNA is equimolar with

• A. Uridine
• B. Thymine
• C. Guanine
• D. Cytosine

Answer 1

The correct option is B Thymine

The nitrogenous bases are purines and pyrimidines. The purines are adenine and guanine. The pyrimidines are thymine and cytosine. The purines are double ring structure while the pyrimidines are the single ring made up of carbon and nitrogen. Purines pair with the pyrimidines by hydrogen bonds. Adenine pairs with thymine by two hydrogen bond while the cytosine pairs with the guanosine by three hydrogen bonds. The number of adenine is equal to the number of thymine. According to Chargaff's rule, 1:1 ratio exists between pyrimidine and purine bases.

So, the correct answer is option B.