Here's a breakdown:

* Centromere: This is a constricted region on the chromosome where the two sister chromatids (identical copies of a chromosome) are held together.

* Spindle Apparatus: This is a structure made of microtubules that forms during cell division (mitosis or meiosis). It's responsible for separating the sister chromatids and moving them to opposite poles of the cell.

The spindle fibers (microtubules) from the spindle apparatus attach to specialized protein structures called kinetochores, which are located at the centromere of each chromosome.

This attachment allows the spindle fibers to exert force on the chromosomes and pull them apart, ensuring that each daughter cell receives a complete set of chromosomes during cell division.