Dynamical behavior in the modeling of cell division cycle

In this paper we qualitatively analyze mathematical modeling of the cell division cycle established by Novak and Tyson (Novak B, Tyson JJ. J Theor Biol 1993;165:101–34) and discuss the existence, uniqueness, stability and unstability of its singular point and the system boundedness, existence and nonexistence of closed orbit and its global structure.