Consider the following biochemical reactions: [X] + Deoxyribose sugar [Y] [Y] + Phosphate group [Z] Identify X, Y, and Z correctly from the given options.

Step-by-step solution

The given reactions describe the formation of a nucleotide from its components. A nitrogenous base [X] combines with a pentose sugar to form a nucleoside [Y]. Since the sugar is explicitly given as deoxyribose, the base [X] can be Thymine (which is found in DNA), but not Uracil (which is found in RNA and pairs with ribose sugar). Thymine [X] combines with deoxyribose sugar to form the nucleoside Thymidine [Y]. When a phosphate group is attached to the nucleoside Thymidine, it forms the nucleotide Thymidylic acid [Z