In fundamental genetics, which statement best describes the difference between a gene and an allele?

• A. A gene is a DNA sequence that influences a trait, whereas an allele is an alternative version of that gene.
• B. A gene is a trait that an organism shows, whereas an allele is the DNA sequence that produces the trait.
• C. A gene is always dominant, whereas an allele is always recessive.
• D. A gene is a chromosome, whereas an allele is a locus on that chromosome.

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the definition of a gene. A gene is a segment of DNA that contains the instructions to produce a specific protein or influence a particular trait in an organism.
2. Step 2: Understand the definition of an allele. An allele is a variant form of a gene that can exist at a specific locus (position) on a chromosome.
3. Step 3: Recognize that genes can have multiple alleles, which are alternative versions that may result in different expressions of a trait.
4. Step 4: Differentiate between the gene itself (the DNA sequence) and the alleles (the different versions of that sequence) to clarify their relationship.
5. Step 5: Use this understanding to evaluate the given statements and identify the one that correctly describes the difference between a gene and an allele.