In humans, somatic cells are typically diploid with 2n equals 46, while gametes are haploid with n equals 23. Which statement correctly describes this?

• A. Somatic cells are diploid with 2n=46; gametes are haploid with n=23
• B. Both are haploid
• C. Somatic cells are haploid and gametes are diploid
• D. Both are diploid

Answer: (A)

In humans, the difference between diploid and haploid numbers is what sets apart somatic cells from gametes. Somatic cells carry two complete sets of chromosomes—one from each parent—so they are diploid (2n), totaling 46 chromosomes. Gametes, on the other hand, contain only a single set of chromosomes, one from each pair, making them haploid (n) with 23 chromosomes. This distinction arises because somatic cells are produced by mitosis, which preserves the chromosome number, while gametes are produced by meiosis, which halves the chromosome number. When fertilization occurs, a sperm and an egg fuse to restore the diploid number in the resulting zygote. That’s why the description of somatic cells as 2n=46 and gametes as n=23 is correct.