Which of the following statements best defines epistasis? O 1. We have epistasis when interacting genes do not show independent assortment
2. We have epistasis when identical genes produce different expression patterns in the same genotype and environment
3. We have epistasis when an allele at one locus masks the effects of one or more other alleles at the same locus
4. We have epistasis when an allele at one locus modifies the effects of alleles at one or more other loci