What are Haploid and Diploid Cells?

The union of two haploid gametes during fertilization creates a diploid zygote with two sets of chromosomes (46 in humans). These pairs are called homologous chromosomes. All body cells except gametes are somatic cells, which are diploid (2n), meaning they have two sets of 23 chromosomes for a total of 46.

Somatic cells reproduce by mitosis, resulting in two genetically identical diploid daughter cells. Meiosis is a type of cell division that produces four genetically different haploid gametes from a diploid cell through two cell divisions.

Diploid cells have two complete sets of chromosomes (one from each parent), and their chromosome number is written as 2n. All somatic cells are diploid and reproduce through mitosis. Gametes are never diploid.

Gamete cells are always haploid, possessing only one set of chromosomes, which is half the diploid number. Their chromosome number is written as n, and they do not have homologous pairs. Haploid gametes are formed from diploid cells through meiosis, never mitosis.

Sex cells, or gametes, are haploid (n). In humans, each gamete has one set of 23 chromosomes, so the haploid number (n) is 23.

Haploid and diploid describe the number of chromosome sets in a cell. Haploid cells have one set of chromosomes, while diploid cells contain two sets.