Final answer:
Centromeres ensure that each of the sister chromatids become part of a different daughter cell.
Step-by-step explanation:
The structures that ensure that each of the sister chromatids become part of a different daughter cell are called centromeres.
The centromere is a region of DNA that holds the sister chromatids together before they are separated during cell division. It plays a crucial role in ensuring that each daughter cell receives an equal number of chromosomes.