Question

Which represents the correct hexaploid nature of wheat?

| Monosomic| Haploid| Nullisomic| Trisomic
---|---|---|---|---
(A)| 21| 28| 42| 43
(B)| 7| 28| 40| 42
(C)| 21| 7| 42| 43
(D)| 41| 21| 40| 43

(A) A
(B) B
(C) C
(D) D

Answer 1

Wheat belongs to the grass family Poaceae (formerly known as the Gramineae) which, with about 10,000 species, represents one of the largest families of flowering plants. The phenotypic traits of hexaploid crops, like bread wheat, can be easily identified with the genes of wild type and null genes.

Complete answer:
The presence of multiples of complete haploid chromosome sets is called polyploidy. Wheat, Triticum, has an essential chromosome number is n= 7; consequently, the hexaploid species (Triticum aestivum) have 6n= 42. In monosomy, there is the absence of a single chromosome from a diploid cell (2n-1); Nullisomy is the absence of one complete pair of homologous chromosomes (2n-2); haploidy is portrayed by the presence of one complete arrangement of chromosomes as is found in gametes; trisomy is the presence of one chromosome in three-fold (2n+1). Along these lines, for hexaploid wheat; monosomy (2n-1) = 41; haploidy (2n/2) = 21; Nullisomy (2n-2) = 40; trisomy (2n+1) = 43.

Additional Information: Triticum (wheat) includes six organic species at the diploid, tetraploid, and hexaploid levels. The polyploid Triticum species began by hybridization among Triticum and the neighboring family Aegilops. Hexaploid T. aestivum began some 6000–7000 years back by the hybridization of tetraploid wheat. Kinds of wheat within one ploidy level will be more closely related to each other. Ploidy level influences some plant characteristics. For instance, higher levels of ploidy tend to be linked to larger cell size.
So, the correct answer is ‘D’.

Note: Approximately 95% of the wheat currently grown worldwide is hexaploid bread wheat and the remaining 5% are mainly tetraploid durum wheat. Generally, wheat is considered as the world's largest and most important cereal crop for human staple food, with an annual production of > 700 million tonnes produced globally over the past few years.