Define the following terms: Dominant gene and Recessive gene.

(N/A) $1$. Dominant gene: The allele that expresses its phenotypic effect in both homozygous and heterozygous conditions is called a dominant gene.
$2$. Recessive gene: The allele that expresses its phenotypic effect only in the homozygous condition and remains masked in the presence of a dominant allele is called a recessive gene.