In genetic terms, what is an allele?

An allele is defined as a variant form of a gene that occupies a specific position on a chromosome. Genes can come in multiple forms, with each of these forms being termed an allele. For example, in the case of a gene that influences flower color in plants, there may be one allele for red flowers and another allele for white flowers. These different alleles can result in the expression of different traits within the same species.

The understanding of alleles is crucial in genetic studies because they contribute to the genetic diversity observed in populations. This variability is essential for evolution and adaptation. Moreover, alleles can be dominant or recessive, which determines how traits are expressed in an organism.

Considering the other options, a type of RNA is not synonymous with an allele, as that refers to nucleic acids involved in protein synthesis. A dominant gene is a functional aspect relating to how alleles interact rather than a category of alleles themselves. Lastly, a sequence of nucleotides describes the structure of DNA or RNA itself but does not specifically define what an allele is, as alleles are broader concepts associated with gene variants rather than individual nucleotide sequences.