Which term describes different variants of a gene?

Which term describes different variants of a gene?

• A. Diploid
• B. Estrus
• C. Congenital defects
• D. Alleles

Answer: (D)

Alleles are the different versions of a gene that occupy the same position on homologous chromosomes. They arise by mutation and create variation in inherited traits. In a diploid organism, you carry two alleles for each gene—one from each parent—so you can be homozygous (two of the same allele) or heterozygous (two different alleles). This is why the concept of alleles best fits “different variants of a gene.” The other terms describe unrelated ideas: diploid refers to having two chromosome sets, estrus is a reproductive phase in some animals, and congenital defects are birth conditions, not the variant forms of a gene.

Alleles are the different versions of a gene that occupy the same position on homologous chromosomes. They arise by mutation and create variation in inherited traits. In a diploid organism, you carry two alleles for each gene—one from each parent—so you can be homozygous (two of the same allele) or heterozygous (two different alleles). This is why the concept of alleles best fits “different variants of a gene.” The other terms describe unrelated ideas: diploid refers to having two chromosome sets, estrus is a reproductive phase in some animals, and congenital defects are birth conditions, not the variant forms of a gene.