Chapter 13, Problem 20P

Summary Introduction

To analyze:

Visual of human chromosome $\text{5}$ and the corresponding chromosome from chimpanzee, gorilla, and orangutan. The structural differences between human chromosomes and primate chromosomes.

Introduction:

Chromosome mapping is the arrangement of the chromosomes. Genetic mapping provides the clue about the position, structure and, location of the chromosomes.

To study the cytogenetics of chromosome; the G-banding or Giemsa banding technique is used. A karyotype is the arrangement and appearance of the chromosomes in the nucleus of the eukaryotic cell. Karyotyping specifically did to study the number of chromosomes, positions, banding pattern or differences between the sex chromosomes.

It is very challenging to figure out these aspects with simple staining procedures that applies uniform color to all structures or parts of the chromosome.

Hence, G-banding technique was developed that specifically highlights light and dark bands.

G-Banding is useful in the detection of genetic diseases through photographic visualizations of the entire chromosome.

In this technique- the metaphase chromosomes are partly digested and treated with trypsin, later stained with the Giemsa stain.

The dark bands refer to the rich A and T regions while light regions refer to the G and C rich regions.