what makes homologous chromosomes homologous? Solution Answer: Homologous chromosomes are the chromosomes that have exactly the same length that contain the same gene but those genes have different alleles. Homologous chromosomes become pair during meiosis. Two homologous chromosomes become a tetrad during meiosis by having four chromatids. One pair comes from the father and the other, from the mother.The homologous chromosomes are the same size, their centromeres arein the same postition, they have the same number of genes, arranged in the sameorder. The main definition is Chromosomes that have the same length, appearanceand copies of genes, although the alleles may differ.