Alleles are a pair of genes that occupy a specific location on a particular chromosome and control the same trait.
Alleles may appear in pairs or in multiple forms of alleles, which affect a specific trait of the offspring. Locus is the location where a gene is found on a chromosome. A pair of alleles determine the same trait, for example, eye color; one allele codes for black eyes, and another allele codes for brown eyes.
All the alleles found in an organism make up the genotype. If a pair of alleles are similar, the organism’s genotype is called homozygous. If the pair of alleles are different, the organism’s genotype is called heterozygous. A dominant allele will overrule the characteristics of a submissive allele in a heterozygous genotype. But in some traits, an allele is neither dominant nor recessive. For example, the human blood group ABO.
Frequently Asked Questions on Allele Definition
Alleles are defined as the pairs of genes, occupying a particular spot on a chromosome.
How many alleles are in a gene?
As genes are found in more than one version, a living organism can have two of the same alleles of a gene or two different alleles.
- Co-dominance and Multiple Alleles Based on Blood Group System
- Difference Between Homozygous and Heterozygous
To explore more about allele definition, or any other definitions in Biology, register at BYJU’S.