During anaphase I of meiosis, what occurs with the chromosomes?

During anaphase I of meiosis, homologous pairs of chromosomes are separated and move toward opposite poles of the cell. This process is crucial for reducing the chromosome number by half and ensures that each resulting daughter cell will receive one chromosome from each homologous pair.

In this phase, the spindle fibers attach to the homologous chromosomes, aligning them at the metaphase plate during metaphase I, and then during anaphase I, the homologous chromosomes (each consisting of two sister chromatids) are pulled apart and segregated into two different daughter cells. This separation of homologous chromosomes is a defining feature of meiosis I, distinguishing it from meiosis II, where the sister chromatids are separated.

The other options describe processes that do not occur during anaphase I. For example, sister chromatids being pulled apart relates to anaphase II of meiosis, chromosome replication occurs prior to meiosis during the S phase of the cell cycle, and alignment at the spindle equator takes place during metaphase, not anaphase. Therefore, the correct choice accurately reflects the key event occurring during anaphase I.