Question

Match the columns.

a	Monoploidy	$1$	$2n-1$
b	Monosomy	$2$	$2n+1$
c	Nullisomy	$3$	$2n+2$
d	Trisomy	$4$	$2n-2$
e	Tetrasomy	$5$	n
		$6$	$3n$

• A. a-$6$, b-$5$, c-$3$, d-$4$, e-$2$
• B. a-$5$, b-$2$, c-$4$, d-$1$, e-$3$
• C. a-$5$, b-$1$, c-$4$, d-$2$, e-$3$
• D. a-$1$, b-$5$, c-$3$, d-$2$, e-$4$
• E. a-$2$, b-$1$, c-$3$, d-$6$, e-$5$

Answer 1

Answer: (C)

a-$5$, b-$1$, c-$4$, d-$2$, e-$3$

Aneuploidy is the presence of chromosome number that is different from the simple multiple of the basic chromosome number. An organism which contains one or more incomplete chromosome sets is known as aneuploid.

• Monosomy is the phenomenon where an individual lacks one or a few non-homologous chromosomes of a diploid complement. (2n-1)
• The plants in which a chromosome pair is missing, are called nullisomics. The chromo­some formula would be (2n – 2).
• Trisomies are those organisms, which have an extra chromosome (2n+1).
• A tetrasomy is a form of aneuploidy with the presence of four copies, instead of the normal two, of a particular chromosome.
• Ploidy refers to the number of sets of homologous chromosomes in the genome of a cell or an organism. Each set is designated by n. Thus, the state of having a single set of chromosomes is referred to as monoploidy.

So, the correct answer is 'a-5, b-1, c-4, d-2, e-3'.