Question

The phenomenon in which an allele of one gene suppresses the activity of an allele of another gene is known as

• A. Dominance
• B. Epistasis
• C. Suppression
• D. Inactivation

Answer 1

The correct option is B

Epistasis

The correct option is B.

Explanation for the correct option:

1. The state is known as "epistasis" which occurs when the expression of one or more additional genes alters (e.g., masks, inhibits, or suppresses) the expression of a specific gene.
2. Mice's pigmentation serves as an example of epistasis.

Explanation of incorrect options:

Option A:

1. When one allele (variant) of a gene on one copy of chromosome masks or overrides the effect of another allele (variant) of the same gene on the other copy of the chromosome, this occurrence is known as dominance in genetics.
2. For instance, because the gene for brown eyes is dominant, having brown eyes only requires one copy of the 'brown eye' allele (although, with two copies you will still have brown eyes).

Option C:

1. Genetic suppression occurs when a mutation in a different gene compensates for the phenotypic deficiencies brought on by a particular gene mutation.
2. For instance, a mutation that lowers a gene's expression may be repressed by a different mutation that lowers protein degradation.

Option D:

1. Gene silence/inactivation is widely understood to be the inactivation of previously active individual genes or larger chromosomal regions as a result of an epigenetic alteration of gene expression.
2. An orange or black coat color arises from the X-linked fur pigmentation gene in cats, depending on which copy of the X chromosome each cell choose to keep active.

Final answer: The phenomenon in which an allele of one gene suppresses the activity of an allele of another gene is known as epistasis.