During anaphase 1 chromosomes in the homologous pair moves to the opposite poles.
The chromosomes that are having their pairs with similar length, position of centromere and staining pattern refers to the homologous chromosomes. These chromosomes have genes with the corresponding loci. One of these chromosomes will be inherited from the father and the other will be inherited from the mother.
The chromosomes in the pair gets attached to the fibers from the opposite poles. The chromatids that are sister will get attached to the fiber from the same poles. The centromere will not get divided during the anaphase 1 and thus the homologous chromosomes will move to the opposite poles. This causes the homologous chromosomes to get separated.