Which term describes two complete sets of chromosomes (2n)?

Which term describes two complete sets of chromosomes (2n)?

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

Answer: (B)

Two complete sets of chromosomes are called diploid. In diploid organisms, somatic cells contain homologous chromosome pairs, one set inherited from each parent. The 2n notation literally means there are two complete chromosome sets, with n representing the number of chromosomes in a single set. Meiosis in germ cells reduces the number to n, so gametes have one set, and fertilization restores two sets in the zygote, maintaining species-specific chromosome numbers. By contrast, haploid refers to a single set (n), polyploid means more than two complete sets (such as 3n or 4n), and aneuploid describes an abnormal chromosome number that isn’t a simple multiple of the haploid set.

Two complete sets of chromosomes are called diploid. In diploid organisms, somatic cells contain homologous chromosome pairs, one set inherited from each parent. The 2n notation literally means there are two complete chromosome sets, with n representing the number of chromosomes in a single set. Meiosis in germ cells reduces the number to n, so gametes have one set, and fertilization restores two sets in the zygote, maintaining species-specific chromosome numbers. By contrast, haploid refers to a single set (n), polyploid means more than two complete sets (such as 3n or 4n), and aneuploid describes an abnormal chromosome number that isn’t a simple multiple of the haploid set.