  We study the evolution of the [O/Fe]-[Fe/H] relation and the dependence of
the iron abundance on distance from the galactic plane z in a one-zone model
for a disk galaxy, starting from the beginning of star formation (Wiebe98). We
obtain good agreement with the observational data, including, for the first
time, agreement for the [Fe/H]-z relation out to heights of 16 kpc. We also
study the influence of the presence of dark matter in the galaxies on the
star-formation rate. Comparison of the observed luminosity of the Galaxy with
the model prediction places constraints on the fractional mass of dark matter,
which cannot be much larger than the fractional mass of visible matter, at
least within the assumed radius of the Galaxy, 20 kpc. We studied the evolution
of disk galaxies with various masses, which should obey the Tully-Fisher
relation, M \propto R^2. The Tully-Fisher relation can be explained as a
combination of a selection effect related to the observed surface brightnesses
of galaxies with large radii and the conditions for the formation for
elliptical galaxies.
