Definitions

Boson: "An integer-spin particle which mediates forces between fermions. Odd spin bosons mediate repulsive forces; even spin bosons mediate attractive forces. Bosons of the same type are indistinguishable and have symmetric wavefunctions. Bosons obey Bose-Einstein statistics". (http://scienceworld.wolfram.com/physics/Bo son.html)

Grand Unified Theory (GUT): "A valid GUT should explain why the electron, a lepton, and the proton, a composite of quarks, have electric charges of the same magnitude". (Beiser, p.497)

Fermion: "An odd half-integer spin particle. Fermions act on each other by exchanging bosons. Examples include leptons (such as the electron), neutrons, protons and quarks. They are indistinguishable, have antisymmetric wave functions, and obey Fermi-Dirac statistics". (http://scienceworld.wolfram.com/physics/Fe rmion.html)

Supersymmetry: "Every particle must have a supersymmetric counterpart – a sparticle – whose spin differs from its own by ½." (Beiser, p.497)