Final answer:
TRNE repeats involve expansion of nucleotides within introns of genes.
Step-by-step explanation:
Nucleotides are the basic building blocks of nucleic acids, which include DNA (deoxyribonucleic acid) and RNA (ribonucleic acid).
TRNE repeats involve expansion of nucleotides. In eukaryotes, genes have introns which are non-translated sequences that interrupt the translated exons. The introns tend to be longer than the exons, and the expansion of TRNE repeats often happens within the introns. This can result in repeated regions of the same amino acid in protein sequences.