Alleles are different versions of a gene that can exist at a specific locus (position) on a chromosome. While the DNA sequence of a gene determines the traits it influences, variations in the sequence can result in different expressions of that gene, leading to variation in traits. For example, a gene that determines flower color may have one allele for red petals and another for white petals.
Humans typically have two alleles for each gene, one inherited from each parent. Alleles can be dominant or recessive:
- Dominant alleles: These can mask the effect of recessive alleles. If an individual has one dominant allele, the trait it represents will be expressed.
- Recessive alleles: These only express their effect if an individual has two copies (i.e., is homozygous for that allele).
The combination of alleles that an individual has is called its genotype, and the observable traits resulting from that genotype are referred to as the phenotype.
If you have more specific questions about alleles, their functions, or related topics, feel free to ask!
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