Final answer:
Two genes are considered alleles if they are alternative versions of a gene at the same locus on homologous chromosomes, not at different loci, making the statement false.
Step-by-step explanation:
The correct answer to the question is b. False. For two genes to be considered alleles, they must be alternative versions of a gene at the same locus (position) on homologous chromosomes. Alleles account for the variation in traits such as hair color or blood type because they can have different nucleotide sequences that result in different manifestations of a trait. When individuals have two identical alleles for a trait, they are homozygous for that gene. Conversely, if they have two different alleles for a gene, they are heterozygous for that trait.