Answer:
Comparative genomics is a field of biological research in which the genome sequences of different species — human, mouse, and a wide variety of other organisms from bacteria to chimpanzees — are compared. By comparing the sequences of genomes of different organisms, researchers can understand what, at the molecular level, distinguishes different life forms from each other. Comparative genomics also provides a powerful tool for studying evolutionary changes among organisms, helping to identify genes that are conserved or common among species, as well as genes that give each organism its unique characteristics.
What Is a Genome Made Of?
Although living creatures look and behave in a myriad of ways, all of their genomes consist of DNA, the chemical chain that harbors the genes that code for thousands of different kinds of proteins. Within DNA are the instructions sufficient to make an organism and the means by which organisms pass information along to their offspring. Remarkably, this information is coded by only four nucleotides: adenosine (A), cytosine (C), guanine (G), and thymine (T). Understanding the order of these nucleotides in linear DNA molecules has been an active pursuit since the discovery of DNA’s double-helical structure (Watson et al. 1953). As such, DNA sequencing has emerged as a fundamental approach to molecular biology research. The power of DNA sequencing as a research tool has spurred the dramatic advancement of DNA sequencing technology, which is allowing ever more genomes to be sequenced and making comparative genomics an accessible focal point for the study of any form of life.
