Q. In which one of the following combinations (a-d) of the number of the chromosomes is the present day hexaploid wheat correctly represented? [table] Combination | Monosomic | Haploid | Nullisomic | Trisomic [/table]
A) 27-28-42-43
B) 7-82-40-42
C) 21-7-42-43
D) 41-21-40-43
Explanation
The basic chromosome number of wheat is 7(x=7) and its hexaploid species contain 42(6$\times 7)$ chromosomes. Thus, it’s monosomic (one chromosomes missing) contains 41(42-1) chromosomes. Haploid contains 21 (half to the 42) chromosomes. Nullisomic (one chromosome pair missing) contains 40(42-2) chromosomes and trisomic contain (one chromosome extra) 43(42+1) chromosomes.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.