Which term describes chromosomes that have the same genes at the same loci, one inherited from each parent?

• A. Homologous
• B. Sister chromatids
• C. Nonhomologous
• D. Chromosome pairings

Answer: (A)

Homologous chromosomes describe a pair that carries the same genes in the same locations (loci), with one chromosome inherited from the mother and the other from the father. They are similar in structure and gene order, but can carry different versions (alleles) of those genes, which is why siblings can vary in traits. They are not identical copies—that role belongs to sister chromatids, which are created when DNA is replicated and stay attached until cell division. Nonhomologous chromosomes do not share the same genes at the same loci and do not pair with each other. During meiosis, homologous chromosomes pair up and can exchange genetic material through crossing over, contributing to genetic diversity while preserving the same set of genes and their order.