The process of arranging paired chromosomes from largest to smallest is called karyotyping.

Here's a breakdown:

* Karyotype: A complete set of chromosomes in a cell, arranged in order of size and shape.

* Chromosomes: Structures within the nucleus of a cell that contain the genetic material (DNA).

* Paired chromosomes: In most organisms, chromosomes come in pairs (one from each parent).

During karyotyping, chromosomes are stained and photographed, then arranged in pairs based on their size, shape, and banding patterns. This allows scientists to identify any abnormalities in chromosome number or structure.