Which term describes different forms of a gene?

• A. Gene
• B. Allele
• C. Trait
• D. Fertilization

Answer: (B)

Different forms of a gene are called alleles. Alleles are versions of the same gene that occupy the same position (locus) on homologous chromosomes. They arise from variations in the DNA sequence and explain why the trait governed by that gene can appear in different forms among individuals—for example, different eye colors or blood types. Alleles can be dominant or recessive, influencing which trait is seen in the organism’s phenotype depending on the combination inherited from the parents. A gene is a basic unit of heredity, a trait is the observable characteristic, and fertilization is the union of gametes.