Question

. Explain euploidy and its subtype?​

Answer 1

Answer:

Euploldy is the presence of chromosome number which is the multiple of the basic chro­mosome set. An organism with the basic chro­mosome number 7, may have euploids with chromosome number 7, 14, 21, 28, 35, 42. Euploids are further of different types – monoploids, diploids and polyploids.

In monoploids there is a single set of genome, in diploids there are two sets of genome and in polyploids there are more than two sets of genome.

Symbols of chromosome number:

2n = Somatic chromosome number of a diploid or polyploid species.

n = Gametic chromosome number of a diploid or polyploid species.

X = Basic chromosome number or genomic number.

a diploid species with chromosome num­ber 2n = 14, n = 7 as well as x = 7.

But in a polyploid (hexaploid) species with chromosome number 2n = 6x = 42, n = 21 but X = 7.

Types of Euploidy:

Monoploidy and Haploidy:

Monoploid individuals have single basic set of chromosome, e.g., in barley 2n = x = 7 (haploid of a diploid species). Haploids are indi­viduals with chromosome number half of the somatic number, e.g., in wheat (2n = 3x = 21).

In diploid species, the chromosome number of monoploids and haploids are same, but in poly­ploid species the chromosome number of mono­ploids and haploids are different. In polyploid wheat (6x = 42), the haploid is 3x = 21 and manoploid is x = 7.

In flowering plants, the diplophase or the sporophytic phase dominates; the haplophase or gametophytic phase is normally limited to the pollen grains and the embryo sacs. In excep­tional cases, plants may arise that are entirely haploid. With regard to all their parts, the hap­loids are smaller and often display poor vigour.