  We investigate colorless (mesonic)
  3q-q qbar components in the nucleon and the Roper resonance N*(1440).
  Starting from constituent quarks and gluons we estimate the excitation of
quark-antiquark pairs in a gluon exchange model with the strong coupling
constant extracted from a comparison with a non-perturbative resonating group
calculation of the pi, eta, rho and omega content of the nucleon. Applying the
same model to the Roper resonance, we find as the most striking result a very
strong scalar-isoscalar sigma content of the N*(1440) with a strength of the
3q-q qbar configurations comparable to the 3q component itself.
