Which term describes alleles that are different from one another?

The term that describes alleles that are different from one another is heterozygous. In genetics, an organism is considered heterozygous for a particular gene when it has two different alleles—one inherited from each parent. This is in contrast to being homozygous, where both alleles for a trait are the same.

Understanding heterozygosity is crucial in the context of inheritance since it often influences the organism's phenotype and can provide a more diverse genetic makeup, which can be beneficial for adaptability and survival. Dominant and recessive refer to the expression of particular alleles rather than their differences. Dominant alleles can mask the effect of recessive alleles, but they do not describe the nature of the alleles themselves.