Epistasis

Question 1

Epistasis definition

Answer 1

Describes an interaction between genes at different loci (affecting a single phenotypic trait)
-genes may work antagonistically or in a complementary fashion

Question 2

A gene is said to be epistatic when…

Answer 2

its presence modifies or suppresses the effect of a gene at another locus (the hypostatic gene)

Question 3

Sometimes referred to as…

Answer 3

‘modifying’ or inhibiting’ genes

Question 4

They can be

Answer 4

Dominant or recessive

Question 5

Recessive epistasis

Answer 5

The presence of homozygous recessive alleles at the first locus prevents the expression of another allele at a second locus

Question 6

Dominant epistasis

Answer 6

A dominant allele at the epistatic gene ‘masks’ the hypostatic gene (even if there is a dominant allele present at the hypostatic gene locus)
The presence of a dominant allele at the first locus prevents the expression of another allele at a second locus