What if you mate an F1 back to a Parent? What would that be?
B1 [ back cross 1 ] . It was also used to designate a breeding back to the breed of one parent rather than the specific parent . If you're introducing a new color to a breed , then breeding an F1 or F2 back to the original color of the breed is a back cross , usually done for improoving type [*] once the color is established [ ETA : * without doing an inbreeding ] .