What is the dominance -recessive interaction of an allele pair?

Answer 1

This depends on the type of dominance relationship. You can have true dominance, in which case if the allele pair contains a dominant allele, the dominant trait will be expressed. In this case the recessive trait will only be exhibited if both alleles are recessive.

A second case is that of codominance. In this case, two alleles are codominant, so if you have one of each, both traits will be expressed.

A third case is that of incomplete dominance. In this case, if you have a dominant and a recessive allele, you will get a trait which is a mixture of both traits. A good example is when you breed a red flower and a blue flower and get a purple flower as progeny.

Other things, like dominance series, also exist. However this information should answer your original question.

Answer 2

In a dominance-recessive interaction, one allele (dominant) masks the expression of the other allele (recessive) in a heterozygous individual. The dominant allele is expressed phenotypically, while the recessive allele's traits are not visible. This interaction occurs at the level of gene expression and influences the observable traits or phenotype of an organism.