Question

Select the incorrect matches with respect to the types of aneuploidy observed in human beings. $\begin{array}{ccc}& \text{Types of aneuploidy}& \text{Number of chromosomes}\\ i& \text{Nullisomy}& 44\\ ii& \text{Tetrasomy}& 48\\ iii& \text{Double Trisomy}& 47\\ iv& \text{Monosomy}& 46\end{array}$

• A. i and ii
• B. iii and iv
• C. i and iii
• D. ii and iv

Answer 1

The correct option is B iii and iv

In human beings, the haploid set (n) has 23 chromosomes and diploid set (2n) has 46 chromosomes.

A condition in which there is loss or addition of one or few chromosomes within the normal diploid set is called aneuploidy.

Nullisomy, tetrasomy, double trisomy and monosomy are various types of aneuploidy.

* In nullisomy, there will be 2n-2 = 44 chromosomes.
* In tetrasomy, there will be 2n+2 = 48 chromosomes.
* In double trisomy, there will be 2n+1+1 = 48 chromosomes.
* In monosomy, there will be 2n-1 = 45 chromosomes.