Dominant allele

A dominant allele is the variant of a gene that will produce a certain phenotype and mask the effect of any other variants of the same gene.

  • The dominant allele can produce its phenotype (trait expression) even in the presence of the other form of allele .
  • It is represented using capital letters

Recessive allele

A recessive allele is that variant of a gene that does not create a phenotype (trait expression) in the presence of a dominant allele .

  • It is represented using small letters .

We know that an organism receives one copy of each gene from each parent.

There are 3 different possibilities of inheriting the gene.

Let us take the example of hair colour.

In hair colour, dark hair is the dominant trait and blonde hair is the recessive trait.

  • If both parents pass alleles of dark hair to the child, the child will also have dark hair.


  • If one parent passes traits of dark hair and another parent passes traits of blonde hair , even then the child will have dark hair.
  • A dominant trait is always expressed even if one copy of the dominant allele is received from either of the parents


  • If both parents pass the trait of blonde hair to their child, only then will the child have blonde hair.
  • Recessive trait is expressed only if both copies of the gene are recessive .


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Maninder Singh

CA Maninder Singh is a Chartered Accountant for the past 13 years and a teacher from the past 17 years. He teaches Science, Economics, Accounting and English at Teachoo