Here's why:

* Diploid cells have two sets of chromosomes, one set inherited from each parent.

* Homologous chromosomes are pairs of chromosomes that have the same genes in the same order, but may have different alleles (versions of the gene).

* Since diploid cells have two sets of chromosomes, they have pairs of homologous chromosomes.

Example: Humans have 23 pairs of chromosomes (46 total). Each pair consists of two homologous chromosomes. One chromosome of each pair is inherited from the mother, and the other from the father.

Haploid cells, on the other hand, only have one set of chromosomes and therefore do not have homologous chromosomes.