Final answer:
A diploid organism that has two different alleles for a specific gene on each of the homologous chromosomes is known as heterozygous.
Step-by-step explanation:
If a diploid organism has two different versions of a gene on the two homologous chromosomes, this is called Heterozygous. The term heterozygous indicates that the organism has two different alleles for a given gene on their homologous chromosome. For example, an organism may carry one allele for white flower color and another allele for violet flower color, making it heterozygous for the gene controlling the flower color.
Different alleles for a given gene define the organism's genotype, and the manifested traits are expressed as its phenotype. In heterozygous genotype, the two different alleles present can result in a dominant trait being expressed over a recessive one. The term homozygous, on the other hand, refers to having two identical alleles for a given gene, either both dominant or both recessive.
Polyploidy is a separate condition where an individual has more than two sets of chromosomes, which is different from being heterozygous or homozygous for a particular gene.