What characterizes a recessive trait?

A recessive trait is characterized by being expressed only when two copies of the recessive allele are present. This means that an individual must inherit the recessive allele from both parents to manifest the trait. If only one copy of the recessive allele is present alongside a dominant allele, the dominant trait will expressed instead, effectively masking the recessive trait.

In genetic terms, alleles are different forms of a gene. Dominant alleles will override the effect of recessive alleles, leading to the expression of the dominant trait in heterozygous individuals (those with one dominant and one recessive allele). It is only in homozygous recessive individuals, who have two recessive alleles, that the recessive trait becomes observable. Understanding this relationship between dominant and recessive alleles is essential in genetics and inheritance patterns.