What is the relationship between alleles and genes?

The correct assertion highlights that alleles are different forms of the same gene, which illustrates the concept of genetic variation within a population. A gene is a sequence of DNA that encodes for a particular trait, while alleles are the various versions of that gene that may produce distinct phenotypes. For example, a gene that dictates flower color in a plant may have one allele for red flowers and another for white flowers. This diversity among alleles contributes to the heritable differences observed in traits among individuals within a species, forming the basis for inheritance patterns.

The other choices do not accurately describe the relationship between alleles and genes. Some may misconstrue alleles as being completely identical to genes or as carrying them, which they do not; instead, they are the variants of those genes. Thus, understanding the nature of alleles as different forms of the same gene is crucial in genetics.