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)

21 and 7

Answer 2

Common wheat is hexaploid$(2n = 6x = 42)$ with three genomes. These three genomes are derived from three different diploid species. (i) Triticum aegilopoides -$A A (2n = 14)$ (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 $7$.