Chapter 24, Problem 1CS

Summary Introduction

To write:

The cause for the change in the number of chromosomes.

Introduction:

All the cells in the human body consist of 23 pairs of chromosomes or a total of 46 chromosomes with exceptions being the gametes (23 chromosomes) and the enucleated red blood cells. Out of which, the 22 pairs of chromosomes are known as the autosomes. The 23^rd pair of the chromosome is known as the sex chromosomes, with XX in females and XY in males.

The change in the number of chromosomes is called aneuploidy and is caused by a process called nondisjunction of chromosomes. It is the failure in the separation of the sister chromatids or pairs of homologous chromosomes during cell division.