Abstract: A teaching aid in the form of manipulative chromosomal models is described. Each chromosomal model contains at least two subunits, each subunit being provided with separable connectors at each end in the form of hook and loop type fasteners. A pair of chromosomal models of contrasting color permits the study of the behavior of the orientations and movements of chromosomal material during the cell reproduction processes of mitosis and meiosis. Simulated centromeres are provided for the further illustration of these biological processes.