What term denotes having two identical alleles for a gene?

What term denotes having two identical alleles for a gene?

• A. Homozygous
• B. Heterozygous
• C. Carrier
• D. Codominance

Answer: (A)

Having two identical alleles for a gene is called homozygosity. In a genotype, this means both copies of the gene are the same allele, such as AA or aa. This contrasts with heterozygosity, where the two gene copies are different (Aa). A carrier is typically a heterozygote for a recessive trait, carrying one normal and one disease-associated allele and often not showing symptoms. Codominance refers to a situation where both alleles in a heterozygote are expressed in the phenotype, as seen with AB blood type.

Having two identical alleles for a gene is called homozygosity. In a genotype, this means both copies of the gene are the same allele, such as AA or aa. This contrasts with heterozygosity, where the two gene copies are different (Aa). A carrier is typically a heterozygote for a recessive trait, carrying one normal and one disease-associated allele and often not showing symptoms. Codominance refers to a situation where both alleles in a heterozygote are expressed in the phenotype, as seen with AB blood type.