The Yukawa couplings of the up, down, charm, strange and bottom quarks, are small at the extremely high energy scale of grand unification, μ μ ≈ ≈ 10 15 G e V . Therefore, the y q 2 term can be neglected in the above equation for all but the top quark. Solving, we then find that y q is increased slightly at the low energy scales at which the quark masses are generated by the Higgs, μ μ ≈ ≈ 125 G e V .