haplodiploidy

Haplodiploidy is a genetic system where sex is determined by the number of chromosome sets an individual possesses. In this system, fertilized eggs develop into diploid females, while unfertilized eggs develop into haploid males. This mode of sex determination is observed in certain insect species.1

Heredity involves genes, which are units of inheritance. In sexually reproducing species, individuals inherit two alleles for each gene, one from each parent. During meiosis, sex cells (gametes) are produced, each containing half the number of chromosomes (haploid). Fertilization restores the diploid number of chromosomes, creating a new individual. Meiosis is a specialized cell division that produces four genetically distinct haploid cells from a single diploid cell. The typical number of chromosomes in somatic cells is diploid (2n), which is twice the haploid (1n) number found in gametes. Some organisms, like male bees (drones), can be haploid, developing from unfertilized eggs.234