Resistivity, ρ(T), and magnetoresistance (MR) are investigated in graphene grown on SiC (0 0 0 1), at temperatures between T ∼ 4-85 K in pulsed magnetic fields of B up to 30 T. According to the Raman spectroscopy and Kelvin-probe microscopy data, the material is a single-layer graphene containing ∼20% double-layer islands with a submicron scale and relatively high amount of intrinsic defects. The dependence of ρ(T) exhibits a minimum at temperature T _m ∼ 30 K. The low-field Hall data have yielded a high electron concentration, n _R ≈ 1.4 10¹³ cm^-2 connected to intrinsic defects, and a mobility value of µ _H ∼ 300 cm² (Vs)^-1 weakly depending on T. Analysis of the Shubnikov-de Haas oscillations of MR, observed between B ∼ 10-30 T, permitted to establish existence of the Berry phase β ≈ 0.55 and the cyclotron mass, m _c ≈ 0.07 (in units of the free electron mass) close to expected values for the single-layer graphene, respectively. MR at 4.2 K is negative up to B ∼ 9 T, exhibiting a minimum near 3 T. Analysis of MR within the whole range of B = 0-10 T below the onset of the SdH effect has revealed three contributions, connected to (i) the classical MR effect, (ii) the weak localization, and (iii) the electron-electron interaction. Analysis of the ρ(T) dependence has confirmed the presence of the contributions (ii) and (iii), revealing a high importance of the electron-electron scattering. As a result, characteristic relaxation times were obtained; an important role of the spin-orbit interaction in the material has been demonstrated, too.