Which statement best defines haploidy?

Which statement best defines haploidy?

• A. A cell with two complete sets of chromosomes
• B. A cell lacking a nucleus
• C. A cell with no chromosomes
• D. A cell with one complete set of chromosomes

Answer: (D)

Haploidy refers to having a single complete set of chromosomes. A cell with one complete set of chromosomes is haploid (often denoted n). This is different from a diploid cell, which contains two complete sets (2n). For example, human gametes (sperm and egg) are haploid, carrying 23 chromosomes, while most body cells are diploid with 46. Meiosis produces haploid gametes from a diploid precursor, and fertilization restores diploidy when two haploid sets come together. The other statements describe cells that lack a nucleus or lack chromosomes altogether, or describe two chromosome sets, none of which matches the definition of haploidy.

Haploidy refers to having a single complete set of chromosomes. A cell with one complete set of chromosomes is haploid (often denoted n). This is different from a diploid cell, which contains two complete sets (2n). For example, human gametes (sperm and egg) are haploid, carrying 23 chromosomes, while most body cells are diploid with 46. Meiosis produces haploid gametes from a diploid precursor, and fertilization restores diploidy when two haploid sets come together. The other statements describe cells that lack a nucleus or lack chromosomes altogether, or describe two chromosome sets, none of which matches the definition of haploidy.