Chromatids
Sister chromatids are 2 identical strands of DNA, held together at the centromere after being copied in the S-Phase of the Cell cycle [1]. During mitosis chromatids separate, each entering identical daughter cells.
Dyad
A dyad [2] is a sister pair of chr[[Image:]]omatids. These are generated in prophase 1 of meiosis. The two sisters line up side by side and share a centromere.