Question

Phenomenon of an allele of one gene suppressing the activity of allele of another gene is called
A) Dominance
B) Epistasis
C) Suppression
D) Inactivation

Answer 1

An allele is one, two or more forms of a gene. An individual inherits two alleles for each gene, one from the maternal parent and one from the paternal parent. If the two alleles are the same the individual is said to be homozygous and if the two alleles are different, the individual is said to be heterozygous.

Complete answer:
A) Dominance : Dominance is a phenomenon in which one allele of a gene on a chromosome makes the effect of the second allele of the same gene on the other copy of the chromosome.The first allele is called the dominant allele and the second allele is called as the recessive allele.The individuals having two different alleles are called heterozygous.
Epistasis : Epistasis is a phenomenon in which an allele of one gene suppresses the activity of an allele of another gene. The gene that determines whether a trait will be expressed or not is called the epistatic gene.The gene whose phenotype is altered by the expression of another allele at a separate locus is called the hypostatic gene.
Suppression : When a mutation occurs, the genotypic as well as phenotypic character of the organism changes.In order to suppress the effect of first mutation, another mutation has to be done.The second mutation suppresses the effect of first mutation.This process is called as the suppression.Any alteration that removes the toxic protein or prevents it from acting is called as the suppressor.
Inactivation : Inactivation is a phenomenon in which certain genes get inactivated and stop functioning.
Therefore, it has been clear from the above discussion that the phenomenon of an allele of one gene suppressing the activity of allele of another gene is called Epistasis.

Hence, option B is the correct answer.

Note: The concept of the epistasis originated in genetics in 1907 but now this phenomenon is also used in the fields of biochemistry, computational biology and evolutionary biology.