In mitosis, no bivalents are formed due to no crossing over of genetic material between chromatids, unlike meiosis where bivalents are formed during Chiasma
In Meiosis a bivalents are formed during the first stage of meiosis which is the prophase. The bivalent consist of a paired chromosome and four chromatids i.e two chromosomes in a tetrad. one chromosome comes from each parent.
In mitosis, a bivalent is not formed. There is the presence of chromatids, homologs, centromeres and spindles during mitosis and meiosis.