Different alleles for a trait are called

• A. Homozygous
• B. Allele
• C. Heterozygous
• D. Gene

Answer: (C)

Two different versions of a gene for a trait exist as alleles. When an organism has two different alleles at that gene, its genotype is heterozygous. This describes having one allele on one chromosome and a different allele on the homologous chromosome. The term allele refers to a single version, while a gene is the unit that contains the genetic information. If both alleles are the same, the organism is homozygous (two identical alleles). For example, with eye color alleles B (brown) and b (blue), a Bb individual is heterozygous.