diploida

Diploida is a term used in genetics to denote the condition of having two complete sets of chromosomes in a cell or organism. In English, the corresponding concept is diploidy or the diploid state. An organism is diploid (2n) when its somatic cells carry two homologous chromosome sets, one inherited from each parent. The gametes produced by meiosis are haploid (n), and fertilization restores diploidy in the zygote.

Genetic organization in a diploid genome allows heterozygosity at many loci, providing genetic diversity and, in many cases, protection against recessive deleterious mutations. During meiosis, homologous chromosomes pair and recombine, generating new combinations of alleles. The two chromosome sets can, however, present challenges for selection and mutation masking, since recessive traits may be hidden in heterozygotes.

In animals and many plants, the diploid phase is the dominant life stage, with development proceeding from a zygote to diploid multicellular bodies. Some lineages, such as many fungi and bryophytes, alternate between haploid and diploid stages, but the details vary widely by group.

Diploidy is a baseline condition for most cytogenetic and genetic analyses. It is assessed by karyotyping, flow cytometry, and genome sequencing. In agriculture and breeding, maintaining or manipulating diploidy, as well as creating polyploids, are important tools for trait conservation and improvement.