Fidel Priestonn,
39 Bartok Bela korut Szombathely,
Szombathely 9700
Hungary
Last updated: October 14, 2010
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http://en.wikipedia.org/wiki/Haploid#Haploid_and_monoploid
As stated above, the haploid number (n) is the number of chromosomes in a gamete of an individual, and this is distinct from the monoploid number (x) which is the number of unique chromosomes in a single complete set. Gametes (germ cells, sex cells, sperm, and ova) are haploid cells. The haploid gametes produced by (most) diploid organisms are monoploid, and these can combine to form a diploid zygote, for example most animals are diploid and produce monoploid gametes.
During meiosis, germ cell precursors have their number of chromosomes halved by randomly "choosing" one homologue, resulting in haploid gametes. Because homologous chromosomes usually differ genetically, gametes usually differ genetically from one another.
All plants and many fungi and algae switch between a haploid and a diploid state (which may be polyploid), with one of the stages emphasized over the other. This is called alternation of generations. Most fungi and algae are haploid during the principal stage of their life cycle.
Male bees, wasps, and ants are haploid organisms because of the way they develop from unfertilized, haploid egg cells.
In humans, the monoploid number (x) equals the haploid number (n), x = n = 23, but in some species (especially plants), these numbers differ. Common wheat has six sets of chromosomes in the somatic cells, derived from its three different ancestral species. The gametes of common wheat are considered as haploid since they contain half the genetic information of somatic cells, but are not monoploid as they still contain three complete sets of chromosomes (n = 3x).
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Fidel Priestonn,
39 Bartok Bela korut Szombathely,
Szombathely 9700
Hungary
Last updated: October 14, 2010