By David Chandler
Updated Mar 24, 2022
The diploid number represents the total count of chromosomes that an organism carries in its somatic cells—two complete sets, one from each parent. In humans, this is 46 chromosomes.
Chromosomes are long strands of DNA folded into compact structures. In eukaryotes, they are typically linear and numerous, each carrying thousands of genes.
The haploid number is the chromosome count of a single complete genome. Gametes (sperm and egg) contain this number; in humans it is 23.
Mitosis is the division of a diploid parent cell into two diploid daughter cells, ensuring that each new cell inherits the full chromosome complement.
Meiosis reduces the chromosome number by half, producing four haploid gametes from one diploid parent cell. This process introduces genetic variation through recombination.
When a haploid sperm fuses with a haploid egg, the resulting zygote is diploid, restoring the organism’s full chromosome set. In humans, the zygote contains 46 chromosomes.
Some organisms have more than two sets of chromosomes—polyploidy—which can confer advantages such as increased vigor or new traits. This is common in many plants.
