Question

Aneuploidy is a chromosomal disorder where chromosome number is not the exact copy of its haploid set of chromosomes, due to :
(a) Substitution
(b) Addition
(c) Deletion
(d) Translocation
(e) Inversion
Choose the most appropriate answer from the options given below

• (c) and (d) only
• (d) and (e) only
• (a) and (b) only
• (b) and (c) only

Answer 1

The Correct Option is D

Aneuploidy is defined as an irregular chromosome count that is not a multiple of the haploid set. This condition stems from errors in chromosome segregation during meiosis.
Addition (B) and Deletion (C): These events directly result in aneuploidy. Nondisjunction, characterized by the failure of chromosomes to separate properly, can lead to either the addition or deletion of chromosomes in gametes.
Substitution (A): This process involves the replacement of one nucleotide with another and does not alter the total chromosome number.
Translocation (D): This refers to the transfer of a chromosomal segment to a nonhomologous chromosome. Although it can lead to other genetic disorders, balanced translocations do not directly cause aneuploidy as the overall chromosome count remains unchanged.
Inversion (E): This involves the reversal of a chromosomal segment end-to-end, which does not affect the chromosome number.