  By means of 2--D chemodynamical simulations, we study the evolution of dwarf
galaxies with structural parameters similar to IZw18 and to tidal dwarf
galaxies. Different sets of yields from intermediate-mass stars are tested, in
order to discover which one best reproduces the observed chemical compositions
(in particular for nitrogen). Different choices of yields from
intermediate-mass stars lead to differences of up to 0.3--0.6 dex, depending on
the assumptions. It is also shown that, given the dependence of the cooling
function on the metallicity, the dynamics of galaxies is also significantly
affected by the choice of nucleosynthetic yields.
