Question

Match List - I with List - II.

List - I	List - II
A. Haploid B. Allotetraploid C. Monosomic D. Trisomic	I. One chromosome missing II. Two distinct genome and each has two copies III. Gametic chromosome number IV. One chromosome extra

• A. А-ІІІ, В-II, C-I, D-IV
• B. A-I, В-II, C-III, D-IV
• C. A-IV, В-III, C-II, D-I
• D. А-III, В-II, C-IV, D-I

Hint:

Aneuploidy memory aid: 'Somic' refers to individual chromosomes. Monosomic = minus one ($2n-1$); Trisomic = triple/three for one pair ($2n+1$).

Answer 1

The Correct Option is A

Concept: Variation in chromosome number is categorized into Euploidy (variations in entire sets) and Aneuploidy (variations in individual chromosomes within a set). Understanding these numerical changes is fundamental to plant genetics and breeding.

Step 1: Define Euploidy terms (A and B).
A Haploid (A) organism or cell has the gametic chromosome number ($n$), which is exactly half the somatic number ($2n$). Therefore, A matches with III. An Allotetraploid (B) is a type of polyploid containing two distinct genomes, each present in two copies (e.g., $2n = 2x_1 + 2x_2$), matching with II.

Step 2: Define Aneuploidy terms (C and D).
A Monosomic (C) individual is missing one chromosome from the diploid set ($2n-1$), matching with I. A Trisomic (D) individual has one extra chromosome added to the diploid set ($2n+1$), matching with IV.

Step 3: Final Matching.
Matching the pairs: A-III, B-II, C-I, D-IV. This corresponds to Option (1).