two alleles are different

Yes, two alleles can be different from each other. Alleles are alternative forms of a gene that determine a specific trait. For example, in humans, the gene for eye color has alleles for blue, brown, green, etc. If an individual inherits two different alleles for a particular gene, they are said to be heterozygous for that gene. So, in this case, the two alleles are different from each other.