In a diploid organism, the two copies of each chromosome are referred to as

• A. Homologous chromosomes
• B. Alleles
• C. Genes
• D. Chromatids

Answer: (A)

In a diploid organism, two copies of each chromosome form a homologous pair because they carry the same genes in the same order and at the same positions on the chromosome. They may carry different versions of those genes, called alleles, so they aren’t identical, but they are the same chromosome in terms of gene content. This pairing is crucial for proper chromosome alignment and segregation during meiosis, ensuring each gamete gets one copy from each chromosome. It’s different from sister chromatids, which are the two identical copies of a single chromosome that are produced during DNA replication and stay attached until later stages of cell division. Alleles are simply the variants of a gene, and genes are the basic units of inheritance located on chromosomes.