  We show the specific unusual features on chiral gauge anomalies cancellation
in the minimal, necessarily 3-3-1, and the largest
  3-4-1 weak isospin chiral gauge semisimple group leptoquark-bilepton
extensions of the 3-2-1 conventional standard model of nuclear and
electromagnetic interactions. In such models a natural explanation for the
fundamental question of fermion generation replication arises from the
self-consistency of a local gauge quantum field theory, which constrains the
number of the
  QFD fermion families to the QCD color charges.
