Organisms that have two different alleles for the same gene are called?

Organisms that have two different alleles for the same gene are called?

• A. Heterozygous
• B. Homozygous
• C. Monozygous
• D. Allozygous

Answer: (A)

Having two different alleles for the same gene means the organism is heterozygous. In a diploid organism, each gene has two copies, one on each homologous chromosome. If those copies differ (for example, A and a), the genotype is heterozygous. This contrasts with homozygous, where both alleles are the same (AA or aa). The other terms aren’t used to describe this situation; monozygotic and allozygous refer to different concepts (like zygosity or unrelated terminology) and don’t describe having two different alleles for one gene.

Having two different alleles for the same gene means the organism is heterozygous. In a diploid organism, each gene has two copies, one on each homologous chromosome. If those copies differ (for example, A and a), the genotype is heterozygous. This contrasts with homozygous, where both alleles are the same (AA or aa). The other terms aren’t used to describe this situation; monozygotic and allozygous refer to different concepts (like zygosity or unrelated terminology) and don’t describe having two different alleles for one gene.