Epistasis is the effect of one gene affecting the expression of another gene. Dominant epistasis have a dominant allele masking the expression of another gene. Recessive epistasis, on the other hand, have a recessive allele involved in masking the gene expression.
In pigs, curly tail (T) is dominant to straight tail (t). Another pair of genes is epistatis to the genes for tail shape, such that if a pig is homozygous recessive (ee) for the epistatic trait, then a pig has no tail at all. If you crossed two heterozygous pigs (TtEe), what fraction of the baby pigs would you expect to have curly tail? Straight tails? No tails. Show all of your work.