Question

When one gene pair hides the effect of the other unit, this phenomenon is referred as
A. Dominance
B. Mutation
C. Epistasis
D. None of the above

Answer 1

Hint:
Genetics is the study of heredity. The offspring resemble their parents in certain characters. Heredity is the passing of physical or mental characteristics from one generation to another from the parents to offspring.
Gene is the unit of inheritance which contains the information which is required to express a particular trait in an organism. Gregor Johan Mendel is the father of genetics who called genes as factors.

Complete answer:
Plants and animals have different characters such as eye color, hair, skin colour, height, weight, colour of flowers, structure of leaves, seeds etc. Alleles are the two genes for the same character which controls the contrasting trait in them. When Mendel experimented with the pea plant he found the concept of dominance which is the masking of one allele of a gene on another or hiding it. The unexpressed or suppressed allele is called the recessive one. It is the state of having two different variants of the same gene.

Cell is the structural and functional unit of life whereas DNA is the blueprint of life. Cell contains a nucleus which contains chromosomes. Chromosomes are made of DNA and a certain fragment of this DNA is called the gene.
DNA is made up of purines and pyrimidines which are sequenced as and so on. When there is a change or any kind of alteration in this sequence it is called mutation. Human evolution is the greatest example of mutation due to internal and external factors.

As dominance is the phenomenon of masking or hiding the effect of one allele of a gene, epistasis is the phenomenon in which a pair of genes hides the effect of the other unit. Red hair, albinism are examples of epistasis in humans. Dominance is intergenic and epistasis is non-allelic.

Hence option C is the correct answer.

Note: The word Epistasis means “standing upon”. In Epistasis genes always affect the same character and it is a broader one and it is of different types such as dominant, recessive, duplicate etc. It is known as interlocus gene interaction.
 So dominance and epistasis should not be confused. Epistasis is an antagonistic gene interaction.