What does heterozygous mean?

What does heterozygous mean?

• A. Having 2 identical alleles for a gene
• B. Having 2 different alleles for a gene
• C. Two genes on homologous chromosomes
• D. A genotype with one chromosome

Answer: (B)

Heterozygous means you have two different alleles at the same gene locus in a diploid organism. You inherit one allele from each parent, and if those alleles differ (for example, A and a or B and b), the genotype is heterozygous. This is distinct from being homozygous, where both alleles at that locus are identical (like AA or aa). Remember, heterozygosity concerns variation at a single gene locus, not two different genes or having only one chromosome.

Heterozygous means you have two different alleles at the same gene locus in a diploid organism. You inherit one allele from each parent, and if those alleles differ (for example, A and a or B and b), the genotype is heterozygous. This is distinct from being homozygous, where both alleles at that locus are identical (like AA or aa). Remember, heterozygosity concerns variation at a single gene locus, not two different genes or having only one chromosome.