Final answer:
Sister chromatids are held together during meiosis I by cohesion proteins at the centromere, which maintains their attachment until anaphase II where cohesions are cleaved, allowing the chromatids to separate.
Step-by-step explanation:
The process that allows sister chromatids to stay together during meiosis I involves the protein complex known as cohesin. During the S phase of interphase, each chromosome is replicated to produce two identical copies termed sister chromatids. These chromatids are held together at the centromere by cohesion proteins.
Throughout meiosis I, and specifically during anaphase I, spindle microtubules pull apart the homologous chromosomes, but the sister chromatids remain attached at their centromeres by cohesion. This attachment is crucial for the proper segregation of chromosomes to ensure that each daughter cell receives the correct number of chromosomes.
This cohesion is maintained until anaphase II, where the cohesion proteins are cleaved, leading to the separation of sister chromatids.