Perhaps?
A model organism can be defined as 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. Model organisms are used to obtain information about other species, including humans that are more difficult to study directly.
Why use a model organism?
Many of the things we study in Biology, such as disease, development and genetics needs to be studied in vivo, to see how pathways and signals, for example, really work. Realistically always studying these in humans would be extremely expensive as well as potentially unsafe and unethical. We use model organisms instead as they provide amazing insight that cannot be gained from lab equipment. What we learn about that animal can then be used to predict what happens in other animals. This is because all living organisms have evolved from the same ancestor and many pathways are the same across different species. In addition, model organisms are readily available, can be easily manipulated and display rapid development with their short life cycles.
Model organisms and their link to humans
References:
1) Twyman, Richard. “What are model organisms? | The Human Genome .” In the genome | The Human Genome . N.p., 28 Aug. 2002. Web. 21 Sept. 2013. http://genome.wellcome.ac.uk/doc_WTD020803.html
2) “Using Model Organisms to Study Health and Disease – National Institute of General Medical Sciences.” NIGMS Home – National Institute of General Medical Sciences. N.p., 12 June 2013. Web. 21 Sept. 2013. http://www.nigms.nih.gov/Education/modelorg_factsheet.htm
3) http://www.prokop.co.uk/Research/LAYMAN/model-animals.gif
The Culture of Biochemistry 
