Diploid refers to how many sets of chromosomes?

• A. One set
• B. No sets
• C. Two sets
• D. Variable

Answer: (C)

Diploid means a cell or organism carries two complete sets of chromosomes. The word breaks down as di- meaning two and -ploid meaning set. In most organisms, somatic cells have two homologous copies of each chromosome—one from each parent—so the total number of chromosomes is two sets (2n). This dual set arrangement is restored after fertilization when two gametes fuse. In contrast, a haploid cell has one set of chromosomes, which is typical of gametes. Some organisms can be polyploid with more than two sets, but diploid specifically refers to two sets.