Containing one set of unpaired chromosomes describes which term?

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

Answer: (A)

Having one complete set of chromosomes means there is only a single copy of each chromosome, so there are no homologous pairs. This state is called haploid, and it is the typical chromosome number for gametes like sperm and eggs in many organisms. When two haploid gametes fuse, they form a diploid zygote with two sets of chromosomes, restoring paired chromosomes. In contrast, diploid cells contain two sets, polyploid describes more than two sets, and monoploid is a rare or context-specific term sometimes used similarly to haploid but not as standard. So, one set of unpaired chromosomes describes the haploid condition.