WordNet records no synonym and no antonym for telomere. It is the only member of its synset, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
either (free) end of a eukaryotic chromosome
“telomeres act as caps to keep the sticky ends of chromosomes from randomly clumping together”
Synonyms, antonyms and the broader and narrower relations for telomere come from Princeton University’s WordNet. Full sources and licences.