  We present the first results of a new set of population synthesis models,
which utilize the latest stellar evolutionary tracks, recent non-LTE atmosphere
models which include stellar winds, and observed line strengths in WR spectra
to predict the relative strengths of various WN and WC/WO emission features in
the spectra of starburst galaxies. Our results will be used to derive accurate
numbers of WN and WC stars in starburst galaxies. We also analyze the frequency
and the WN and WC content of WR-rich galaxies in low metallicity samples; the
theoretical predictions are found to be in good agreement with the observed
frequencies. We also discuss the possible role of massive close binaries in
starburst regions. If the starburst regions are formed in relatively
instantaneous bursts we argue that, given their young age as derived from
emission lines equivalent widths, (1) in the majority of the observed WR
galaxies massive close binaries have not contributed significantly to the WR
population, and (2) nebular HeII 4686 emission is very unlikely due to massive
X-ray binaries.
