Answer the following question given this paragraph: 

During anaphase I the spindle fibers shorten, and the homologous chromosome pairs are separated from each other. This occurs as the chiasmata are severed, pulling homologous chromosomes apart. One chromosome from each pair moves toward one pole, with the other moving toward the other pole, resulting in a cell with 23 chromosomes at one pole and the other 23 at the other pole. Each chromosome still contains a pair of sister chromatids; the sister chromatids remain attached at the centromere.


Q: How many pairs of chromosomes are there?


A:
23