  Existence of heavy mirror analogs of ordinary fermions could explain a
thinkable paradox within the Standard Model direct parity violation. This
paradox is an objectionable possibility to distinguish physically the
left-handed and right-handed coordinate systems. Arguments are presented here
that mirror states can also participate in the formation of the observed SM
quark and lepton mass spectra and their weak mixing properties. 1. With
participation of mirror generations, the quark mixing matrix is similar to the
experimentally observed form. The latter is determined by the restrictions
imposed by the weak symmetry SU(2) and by the quark mass hierarchy. 2. Under
identical conditions and with participation of mirror particles, the lepton
mixing (neutrino mixing) can become very different from its quark analog, the
Cabibbo-Kobayashi-Maskawa matrix, i.e., it can acquire the qualities prompted
by experiment. Such character of mixing evidences in favor of the inverse SM
neutrino mass spectrum and the Dirac (non-Majorana) nature of neutrino.
