Selective breeding involves selecting parents that have characteristics of interest in the hope that their offspring inherit those desirable characteristics.

GMOs are organisms that have had their characteristics changed through the modification of their DNA.

A model organism is a species that has been widely studied, usually because it is easy to maintain and breed in a laboratory setting and has particular experimental advantages.

To develop techniques for DNA sequencing, scientists began by sequencing the genomes of small, simple organisms. As techniques improved it became possible to sequence the genomes of more complex organisms, such as the human genome. Now, we have a large catalogue of genomes that have been sequenced that we can study and compare. 

Humans and mice share many common genetic features and by examining the physiology, anatomy and metabolism of a mouse, scientists can gain a valuable insight into how humans function. 

Baker’s yeast, or Saccharomyces cerevisiae as it is also known, is among the best-studied experimental organisms.

The fruit fly (Drosophila melanogaster) is one of the most well understood of all the model organisms.

Much of our current knowledge about the mechanisms of early development in vertebrates comes from studies using the African clawed frog (Xenopus laevis) and Western clawed frog (Xenopus tropicalis).

While the fruit fly has a long history as a model organism, the nematode worm (Caenorhabditis elegans) has only been used as a model organism since the early 1960s. 

Since the 1960s, the zebrafish (Danio rerio) has become increasingly important to scientific research. It has many characteristics that make it a valuable model for studying human genetics and disease.