The three terms most definitely cannot be used interchangeably, and no scientists or anybody else interested in accuracy does so. Only alleles are dominant or recessive, and this is merely a shorthand way of talking about their effects on particular aspects of phenotype. There is no such thing as a recessive 'gene', only a recessive form (allele) of the gene, though this error is so common in popular culture that one has to deal with it. Likewise, traits themselves are neither dominant nor recessive: one might talk about 'the recessive trait' as being the one produced by two recessive alleles (aa), and 'the dominant trait' as the one produced by two dominant alleles (AA) or one dominant and one recessive (aa). One might also say in 1867 "the wrinkled trait is inherited as a recessive," which is inaccurate but interpretable in 2009 as "if a pea plant inherits two alleles [but not one only] at the starch-branching protein gene locus that produce a form of SBP unable to maintain turgor pressure, its seeds will be unable to retain water and will show a wrinkled phenotype." That is: there is no gene 'for' wrinkled, the trait itself is not inherited (the DNA is), and we call it 'recessive' as a shorthand for two but not one allele like that. Alleles are co-dominant at the DNA level, since both are present as DNA sequences (and may be detected as such), and are often but not always additive, as for example when 'null' alleles contribute no protein product at all to phenotype formation. The discussion of tyrosinase is sufficiently accurate, except again for the confusion of dominant or recessive 'traits'(  )