Answer:
Individuals with different alleles for a single trait are classified as heterozygous.
Explanation:
Zygosity is defined as the degree of similarity of alleles for a given trait. Alleles are the variations in the DNA sequence of a gene, that varies from one organism to another.
A diploid organism is homozygous at a gene locus, when both the alleles for a single trait are same. Whereas, a diploid organism is heterozygous at a gene locus, when both the alleles are different for a single trait.