When a homozygous black, solid-hoofed male pig was mated to a female from a pure breed of red, cloven-hoofed pigs and the F1 progeny were backcrossed to the female breed, the results were 8 black, solid -hoofed, 11 black, cloven-hoofed, 14 red, cloven-hoofed and 10 red, solid-hoofed. What is the genetic basis of the two pairs of alleles?