Final answer:
Methylation occurs on DNA and RNA molecules in eukaryotes, specifically in CpG islands on the DNA and on certain bases in tRNA and rRNA for stability and function.
Step-by-step explanation:
Methylation Occurrence in Pyrimidine in Eukaryotes
In eukaryotes, methylation occurs in various contexts and locations. One important occurrence of methylation in eukaryotes is on the DNA molecule itself, specifically within regions called CpG islands. Methylation of cytosine in the CpG islands can affect gene expression by changing how DNA interacts with proteins. Methylation of DNA is associated with gene silencing and can be influenced by environmental factors.
Additionally, methylation can also occur on RNA molecules in eukaryotes. For example, tRNA and rRNA molecules undergo methylation, where a methyl functional group (-CH3) is added to certain bases for stability. Methylation of RNA molecules can affect their function and stability.