Final answer:
Telomeres are unique to eukaryotic genomes and are not found in prokaryotic genomes. They serve as protective caps at the ends of linear chromosomes in eukaryotes.
Step-by-step explanation:
Among the options available, telomeres are found only in eukaryotic genomes, and not in prokaryotic genomes. Telomeres are the protective structures at the ends of linear chromosomes that help to maintain the integrity of the genetic information during cell division. Prokaryotes, such as bacteria, do not have telomeres because they generally contain a single, circular chromosome without ends that would require protection. Packaging proteins like histones are also generally associated with eukaryotic cells, but some archaea (a type of prokaryote) also have histone-like proteins.