Question

Root cells of wheat have $2n = 42$ chromosomes. Which of the following is the basic chromosome number of wheats?
(A) $7\,$
(B) $14$
(C) $21$
(D) $42$

Answer 1

Hint: The ploidy of the chromosomes is defined as the complete number of the chromosomes present in the body of the organism. The ploidy of the chromosomes is denoted by the number $n$. Like grasses the wheat also exhibits the polyploidy nature of the chromosomes.

Complete Answer:
The given data from the question is
The root cells of the wheat are diploid.
The diploid number of the chromosomes in the wheat, $2n = 42$
It actually means the six sets of the basic number of the chromosomes is $42$.

By taking the wheat crop having the haploid number of the chromosomes. We know that the wheat is hexaploid in nature. It means every chromosome in wheat is present as the six copies of itself.
$2n = 42 = 6x$
Where $x$ represents the number of the basic chromosomes present in the wheat.
By doing the arithmetic operation,
$x = \dfrac{{42}}{6}$
By dividing the terms obtained
$x = 7$
Thus, the number of chromosomes in the wheat is $7$ which is present as the two copies in the root of the wheat plant.

Thus, the option (A) is correct.

Note: The ploidy of the organism is very important this is because it influences the organism’s features or characteristics too. This hexaploid wheat is used in the process of cultivation and the domestication. Wheat within the single ploidy are moreover close to each other. But the polyploidy creates more species in the wheat.