Question

Which type of epistasis occurs when more than one enzyme can carry out a reaction (i.e. you need both loci to be mutant to see a mutant phenotype) ?

Group of answer choices

dominant epistasis

recessive epistasis

duplicate recessive epistasis

genetic redundancy

incomplete penetrance

Answer 1

Ans. (c) duplicate recessive epistasis

The type of epistasis in which recessive alleles at either of the two loci can mask the expression of dominant alleles at the two loci, known as Complementary epistasis or duplicate recessive epistasis. The best example for this is flower colour in sweet pea, where purple colour of flower in sweet pea is shown by two dominant genes say A and B when seperated (AAbb or aaBB) or recessive (aabb) produce white flower. Purple color is shown when both the loci is mutant i.e AaBb or AABB.