Question

Epistasis differs from dominance because
A. In epistasis one gene pair masks the expression of another pair of genes
B. Epistasis is an allelic interaction
C. Many genes collectively controls a particular phenotype
D. One gene pair independently controls a particular phenotype

Answer 1

Hint: Epistasis is an interaction that takes place in between two genes; this interaction influences a phenotype.

Complete Answer:
- Epistasis is a phenomenon that consists of the effect of one gene being depending on the presence of 1 or more 'modifier genes' (genetic background) and the other gene is called hypostatic gene. Similarly, epistatic mutations have exceptional outcomes in aggregate than individually.
- Dominance describes the connection among alleles of the equal gene. Epistasis is not an allelic interaction. It has more than two genes involved.
- A pleiotropic gene is actually one gene which controls multiple traits. Thus, it's far predicted interactions among genes could occur.
- Bateson and Punnett finished a classical test that proved genetic interactions. They analyzed the 3 comb varieties of bird acknowledged to exist at that time. This observation suggests that two genes may control the phenotype of the comb.
- The gene interactions and genotypes had been decided through appearing the best and taking a look at crosses.

Thus, the correct answer is option (A) In epistasis one gene pair masks the expression of another pair of genes.

Note: An example of epistasis is the interaction between hair colour and baldness. A gene for general baldness could be epistatic to at least one for blond hair or pink hair. The hair-color genes are hypostatic to the baldness gene. The baldness phenotype supersedes genes for hair colour, and so the consequences are non-additive.