Epistasis

• Genotype= the genetic makeup of an organism, the alleles it has
• Phenotype= the physical expression of a gene, the phenotype is the result of the interaction of the genotype and the environment
• Epistasis= the interaction of two genes that are located on different chromosomes.

  Can lead to variation between MZ twins.

  Changes in phenotype NOT due to genetic mutations.

  Switching on and off of genes