It is a condition where one or more full sets of chromosomes are present in an organism. The euploids may e Monoploids, Diploids or Polyploids. Monoploids can be distinguished from haploids as they have a single basic set of chromosomes are in Barley 2n = x = 7 or in corn 2n = x = 10 while the Haploids have the half the somatic number of chromosomes found in normal individual i.e. each chromosome is represented once. In some cases as in male insects the haploids are produced due to parthenogenesis. In these insects the queen and drones are diploid females. The haploids also originate due to development of egg parthenogenetically in following plants such as Tomatoes and Cotton. The haploids also originate from pollen tube rather than from egg, synergids or antipodals of the embryo sac. Such haploids are known as Androgenic Haploids.
Significance: Haploids are characterised by a reduction in size of all vegetative and floral parts than a diploid. Haploids are used in production of homozygous diploids as haploids can be doubled by colchicines treatment. These homologous diploids are used for cultivation e.g. rice, wheat and tobacco.
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