Question

Respect the haploid and monoploid numbers of chromosomes of Hexaploid wheat are

• A. 21 and 42
• B. 7 and 21
• C. 21 and 7
• D. 42 and 21

Answer 1

Answer: (C)

Common wheat is hexaploid$(2n=6x=42)$ with three genomes. These three genomes are derived from three different diploid species.
(i) Triticum aegilopoides -$AA(2n=14)$
(ii) Aegilops spelloides - $BB(2n=14)$
(iii) Aegilops squarossa - $DD(2n=14)$
By crossing o f first two diploid species, Triticale dicocioides $(2n=4x-28,$ i.e. tetraploid - A ABB) is produced which on crossing with third species give rise to Triticum aestivum$(2n=6x=42,$ i.e. hexaploid- $AABBDD$). The haploid and monoploid numbers of chromosomes of hexaploid wheat are $21$ and $7$.