Question : In which one of the following combinaations (a-d) of the number of chrmosomer is thepresent day hexaploid wheat correctly represented ?

Question : In which one of the following combinaations (a-d) of the nu

1.	Question : In which one of the following combinaations (a-d) of the number of chrmosomer is thepresent day hexaploid wheat correctly represented ?
Answer» `{:("COMBINATION Monosomic","Haploid","Nullisomic","Trisomic"),(21,28,42,43):}` `{:("Combination Monosomic","Haploid","Nullisomic","Trisomic"),(7,28,40,42):}` `{:("Combination Monosomic","Haploid","Nullisomic","Trisomic"),(21,7,42,43):}` `{:("Combination Monosomic","Haploid","Nullisomic","Trisomic"),(41,21,40,43):}` Solution :The PRESENT oday wheat is heaxaploid, knwn as trictical (2n=42) with 3 GENOMES A and B and D i.e, AABBDD. The 3 genomes are obtained from 3 different dploid species. (i)Triticum aegilkopoids `-A A(2n=4)` (ii) Aegilops speltroides `-BB(2n=14)` (iii) Aegilops squarossa -DD(2n=14) By crossing of first two diploids sps Trictricum dicoccoids (2n=28) i.e., tetraploid is produced AABB which an crossing with third species gives rise to Tricticum oestivuym (2n=42) hexaploid (AABBDD). So its haploid set will have 21 CHROMOSOMES. monosomic (2n-1) will have 41 chromosomes. nullisomic (2n-2) will have 43 chromosomes, and trisomic (2n+1)will have 43 chromosomes,