Which term describes a cell with two complete sets of chromosomes?

• A. Haploid
• B. Monoploid
• C. Diploid
• D. Polyploid

Answer: (C)

Having two complete sets of chromosomes describes a diploid cell. That means the cell has paired homologous chromosomes, with one chromosome of each pair coming from each parent. In humans, somatic (body) cells carry 46 chromosomes arranged as 23 pairs, and this chromosome count is maintained through mitosis to keep the number constant in the organism’s tissues. The opposite concept is a haploid cell, which has a single set of chromosomes (n), such as human gametes (egg and sperm); when these join during fertilization, they restore the diploid number in the zygote. A term sometimes used in certain contexts is monoploid, but it’s not the standard way to describe diploid animal cells. Polyploid refers to cells with more than two chromosome sets (like 3n or 4n), common in many plants. So, two complete sets of chromosomes define a diploid cell.