Final answer:
A dimer of heterochromatin protein 1 (HP1) binds to tightly packed regions of chromatin known as heterochromatin, specifically at the centromere and telomeres of chromosomes.
Step-by-step explanation:
When binding to chromatin, a dimer of heterochromatin protein 1 (HP1) would be found associated with the condensed regions of chromatin known as heterochromatin. Heterochromatin is characterized by its tightly packed DNA, which usually contains genes that are not expressed. This region is typically found at the centromere and telomeres of chromosomes. Therefore, HP1 dimers preferentially bind to these regions of heterochromatin, contributing to the compact structure of chromatin and playing a role in gene silencing, where HP1 is involved in the regulation of gene expression by maintaining the condensed state of heterochromatin.