Final answer:
Pyrimidine nucleosides are named by combining the names of the pyrimidine base and the sugar molecule; the base name is modified by changing the suffix according to a specific pattern.
Step-by-step explanation:
We name pyrimidine nucleosides by the combination of the base and the sugar. A nucleoside is a molecule consisting of a nitrogenous base attached to a sugar molecule. When naming nucleosides, the base name is altered by dropping the -ine and adding -idine for pyrimidines or -osine for purines. For instance, the pyrimidine nucleosides of cytosine, uracil, and thymine become cytidine, uridine, and thymidine, respectively. When a phosphate group or groups are added to a nucleoside, it becomes a nucleotide, which can be classified further based on the number of phosphate groups attached (monophosphate, diphosphate, or triphosphate).