* Centromere: This is the constricted region of a chromosome where the two sister chromatids are attached. It's like the "waist" of the chromosome. The centromere is composed of specialized DNA sequences and proteins that form a complex called the kinetochore. The kinetochore is the point where spindle fibers attach during cell division, pulling the sister chromatids apart.

* Cohesin: This is a protein complex that acts like a "glue" to hold sister chromatids together along their length, particularly at the centromere. Cohesin helps maintain the integrity of the replicated chromosomes during cell division.

* Chromatin: Chromosomes are made up of chromatin, which is a complex of DNA and proteins (histones). These proteins help package and organize the DNA into a compact form, making it easier to fit within the nucleus.

It's important to note that while these structures play a crucial role in holding chromosomes together, there are many other factors that influence chromosome behavior and stability. For example, the overall structure of chromatin, as well as interactions with other proteins, also contribute to the integrity of chromosomes.