  Nucleon resonance contributions to the inclusive proton $F_2$ and $F_L$
structure functions are computed from resonance electroexcitation amplitudes in
the mass range up to 1.75 GeV extracted from CLAS exclusive meson
electroproduction data. Taking into account for the first time quantum
interference effects, the resonance contributions are compared with inclusive
proton structure functions evaluated from $(e,e'X)$ cross section data and the
longitudinal to transverse cross section ratio. Contributions from isospin-1/2
and 3/2 resonances remain substantial over the entire range of photon
virtualities $Q^2 \lesssim 4$ GeV$^2$, where their electroexcitation amplitudes
have been obtained, and their $Q^2$ evolution displays pronounced differences
in the first, second and third resonance regions. We compare the structure
functions in the resonance region with those computed from parton distributions
fitted to deep-inelastic scattering data, and extrapolated to the resonance
region, providing new quantitative assessments of quark-hadron duality in
inclusive electron-proton scattering.
