A recessive trait is a characteristic that is expressed in an organism only when two copies of the recessive allele are present. In genetics, alleles are different forms of a gene. Each individual inherits two alleles for each gene, one from each parent.
If one of the alleles is a dominant allele, it can mask the expression of the recessive allele. This means that if an individual has at least one dominant allele, the dominant trait will be expressed. Recessive traits are only visible when an individual has two recessive alleles (homozygous recessive) for that particular gene.
For example, in the case of flower color in pea plants, the allele for purple flowers (P) is dominant, while the allele for white flowers (p) is recessive. A pea plant with the genotype PP or Pp will have purple flowers, while only a plant with the genotype pp will have white flowers.
Understanding recessive traits is crucial in genetics, as it helps explain inheritance patterns and predict the likelihood of traits being passed on to future generations.