Figure 2.

Homeostasis in the case of low transcription rate. (a) P and M are plotted against time, t. (b) The corresponding solution (magenta line) is plotted in the $PM$ phase plane. P nullcline (dashed blue line), M nullcline (solid red line), Steady state (black dot). Equations (2) were solved numerically. $k_1=0.234$. Other parameter values in Table 1.