So once we replicate the DNA, we form the following two homologous chromosomes. So now, instead of having a single chromatid, we have two cystochromatids is a cystochromatid to this. And because DNA replication produces identical pieces of chromosome, that means these two are identical chromosomes. By the same exact analogy, this is identical to this. So these two are cystochromatids with respect to one another. So these two are cystochromatids.