Q. Which of the following nitrogenous base is present in DNA, but not in RNA? Answer:
Thymine
Notes: Thymine is the nitrogenous base that is present in DNA but not in RNA. Thymine is a pyrimidine base that pairs with adenine through hydrogen bonding in DNA. In RNA, thymine is replaced with uracil, which pairs with adenine.
The four nitrogenous bases in DNA are adenine, guanine, cytosine, and thymine. The four nitrogenous bases in RNA are adenine, cytosine, guanine, and uracil.