How do genes and alleles differ?

Genes and alleles are fundamental concepts in genetics, and understanding their differences is key to grasping how inheritance works. A gene refers to a segment of DNA that encodes instructions for producing proteins or functional RNA molecules. It is essentially the basic unit of heredity.

On the other hand, alleles are different versions of the same gene that arise due to mutations or variations in the genetic sequence. For example, a gene may be responsible for a particular trait, such as flower color in pea plants, and it can exist in several different forms, or alleles, such as purple or white flowers. Each allele may result in a different phenotype, or observable characteristic, depending on which alleles an individual inherits.

This distinction is crucial because it illustrates how genetic diversity occurs within a species and how traits can vary among individuals. Therefore, the correct answer highlights that a gene makes up a section of DNA, while alleles are variations of that specific gene.