Question

Which represents correct hexaploid nature of wheat, representing monosomic, haploid, nullisomic and trisomic respectively?

• A. 12, 28, 42, 43
• B. 7, 28, 40, 42
• C. 21, 7, 42, 43
• D. 41, 21, 40, 43

Answer 1

The correct option is D 41, 21, 40, 43

Presence of multiples of complete haploid chromosomal sets is called as polyploidy. Wheat, Triticum, has basic chromosome number is n= 7; thus the hexaploid species (Triticum aestivum) have 6n= 42. Monosomy is absence of a single chromosome from a diploid cell (2n-1); Nullisomy is absence of one complete pair of homologous chromosomes (2n-2); haploidy is characterized by presence of one complete set of chromosomes as is found in gametes; trisomy is presence of one chromosome in triplicate (2n+1). Thus, for a hexaploid wheat; monosomy (2n-1) = 41; haploidy (2n/2) = 21; Nullisomy (2n-2) = 40; trisomy (2n+1) = 43. This makes option D correct.