| Contents |
| In this paper we study the boundedness and the persistence of the
positive solutions, the existence, the attractivity and the global
asymptotic stability of the unique positive equilibrium and the
existence of periodic solutions concerning the biological model
given by
\[
x_{n+1}=\displaystyle{\frac{ax_n^2}{x_n+b}}+c\displaystyle{\frac{e^{k-dx_n}}{1+e^{k-dx_n}}}
\]
where $0 |
|