What is the difference between homologous chromosomes and sister chromatids?

The differences between homologous chromosomes and sister chromatids include different stages of cell division and structural differences. 1. Different stages of division: Sister chromatids are chromatids located on two different chromosomes of a homologous pair during meiosis. They appear in the middle phase before meiosis begins; homologous chromosomes refer to a pair of chromosomes that are similar in size and shape. 2. Structural differences: Some segments of sister chromatids can be exchanged through crossing over, which is one mechanism of genetic recombination; the number of homologous chromosomes corresponds to the number of centromeres.