Here's what that means:

* Gene: A unit of heredity that determines a specific trait (like flower color).

* Allele: Different versions of a gene.

* Dominant Gene: An allele that masks the effect of the recessive allele.

* Recessive Gene: An allele whose effect is masked by the dominant allele.

* Heterozygous: Having two different alleles for a particular gene.

Example:

Let's say flower color is determined by a gene with two alleles:

* P: Purple flower (dominant)

* p: White flower (recessive)

A plant with the genotype Pp would have one dominant "P" allele and one recessive "p" allele. Since "P" is dominant, the plant would have purple flowers.

So, any plant with one dominant and two recessive genes will have the same phenotype (observable trait) as a plant with two dominant genes.