Question

which statement best describes the relationship between a gene and an allele?

an allele is a variant of a gene.

a gene is always recessive to an allele.

a gene is always dominant to an allele.

a gene is a variant of an allele.

Explanation:

To determine the correct relationship between a gene and an allele, we analyze each option:

• Option 1: An allele is a variant of a gene. This is correct because genes can have different forms (alleles) that code for slightly different traits (e.g., different alleles for eye color within the eye - color gene).
• Option 2: A gene is always recessive to an allele. This is incorrect. Recessiveness or dominance is a property of alleles, not a gene being recessive to an allele. Also, a gene is made up of alleles, and the concept of a gene being recessive to an allele is not a valid biological relationship.
• Option 3: A gene is always dominant to an allele. This is incorrect. Similar to the above, dominance is a property of alleles relative to each other, and a gene is not dominant to an allele in a meaningful biological sense.
• Option 4: A gene is a variant of an allele. This is incorrect. The correct relationship is the reverse - alleles are variants of a gene.

Answer:

A. An allele is a variant of a gene.