Complete dominance also means that a dominant allele can mask or override the effect of a recessive allele if an offspring has inherited different alleles from their parents. Inheriting a dominant allele from one parent and a recessive allele from another parent for a trait is the definition of an individual heterozygous for a trait. Although the organism in question does not physically exhibit the recessive allele, it can be passed on to offspring and possibly demonstrated if the other parent also passes on a recessive allele. In order to know whether or not offspring are heterozygous for a trait, a test crossing two offspring from the same parents can help determine a genotype. If an offspring is found to have two dominant alleles for a trait, they are homozygous dominant for that trait.