Question

Which of the following is incorrect with respect to aneuploidy?

(a) Arises due to the non-disjunction of homologous pair of chromosomes

(b) Arises due to the non-disjunction of non-homologous chromosomes

(c) One gamete comes to have an extra chromosome

(d) Another gamete becomes deficient in one chromosome

This question was posed to me during an online exam.

The query is from Inheritance and Variation Principles in portion Principles of Inheritance and Variation of Biology – Class 12

Answer 1

Correct option is (b) Arises due to the non-disjunction of non-homologous chromosomes

For explanation I would say: Aneuploidy does not arise due to the non-disjunction of non-homologous chromosomes. Instead, it arises due to the non-disjunction of the homologous pair of chromosomes. It results in the formation of gamete with an extra chromosome and the other gamete deficient in one chromosome.