Gene Recessive

A recessive gene is a gene that appears only in a homozygous state. Homozygous means that both copies of the gene in a pair of alleles are the same.

Recessive genes are designated by small letters (for example, a). Dominant genes, on the other hand, are designated by capital letters (A).

For a recessive trait to occur, an organism must inherit recessive alleles from both parents. If a dominant allele is transmitted from at least one parent, then the dominant trait will appear, masking the recessive one.

For example, the allele of the gene that causes brown hair is recessive to the allele that causes black hair. Therefore, brown hair will only appear if the child inherits recessive alleles from both parents.

Thus, a recessive gene can manifest its trait only when in a homozygous state. This is an important feature of the inheritance of many genetic traits.