Spindle fibers move homologous chromosomes to opposite sides is called

Spindle fibers move homologous chromosomes to opposite sides is called anaphase I.

Explanation:

Anaphase I is a stage of meiosis (which is a cell division). During this stage, homologous chromosomes, dragged by the achromatic spindle fibers, are separated towards each pole of the cell.

The achromatic spindle is a set of microtubules, this structure is shaped like two cones joined by their bases. It consists of protein fibers that radiate from each pole. The contraction of these fibers is responsible for the movement of chromatids during anaphase.

At the end of anaphase I, there's a set of chromosomes at each opposite pole of the cell, one of each pair of homologous chromosomes, so the number of chromosomes has been halved.