We study the influence of dynamical quarks on the deconfinement and chiral phase transitions of SU(2) lattice gauge theory using staggered fermions. The pseudo-fermion algorithm is used to include the effects of two flavours of light quarks in a Monte Carlo simulation on lattices of size 83 × 2 and 83 × 4. The systematic errors resulting from a truncation of the algorithm after a finite number of iterations are analyzed. In addition, we perform a weak coupling expansion of thermodynamic observables up to one-loop (order g 2) to study the high-temperature limit of the quark-gluon plasma.