Considering the nucleon as consisting entirely of its valence quarks confined independently in a scalar-vector harmonic potential; unpolarized structure functions F₁(x, μ²) and F₂(x, μ²) are derived in the Bjorken limit under certain simplifying assumptions; from which valence quark distribution functions u_v(x, μ²) and d_v(x, μ²) are appropriately extracted satisfying the normalization constraints. QCD-evolution of these input distributions from a model scale of μ²=0.07 GeV² to a higher Q² scale of Q₀²=15 GeV² yields xu_v(x, Q₀²) and xd_v(x, Q₀²) in good agreement with experimental data. The gluon and sea-quark distributions such as G(x, Q₀²) and q_s(x, Q₀²) are dynamically generated with a reasonable qualitative agreement with the available data; using the leading order renormalization group equations with appropriate valence-quark distributions as the input.