A model organism is a species that has been extensively analyzed and studied due to the fact that it is easy to maintain and breed in a laboratory setting. Models are those organisms with a wealth of biological data that make them attractive to study as examples for other species and/or natural phenomena that are more difficult to study directly.
These specific organisms possess particular experimental advantages which can be further utilized in many research projects. Therefore, this mechanism provides an efficient method of investigating these respective organisms.
Model Organisms can further be classified into three categories:
1) Genetic Model Organism: These are species that are amenable to genetic analysis, i.e. they breed in large numbers and have a short generation time so large-scale crosses can be set up and followed over several generations. Examples include the fruit fly (Drosophila melanogaster) and the nematode worm (Caenorhabditis elegans)
2) Experimental Model Organisms: These species may not necessarily be genetically amenable (i.e. they may have long generation intervals and poor genetic maps) but they have other experimental advantages. For example, the chicken and the African clawed frog Xenopus laevis have many disadvantages in terms of genetics but they produce robust embryos that can be studied and manipulated with ease.
3) Genomic Model Organisms: Regardless of their genetic or experimental advantages and disadvantages, certain species are chosen as model organisms because they occupy a pivotal position in the evolutionary tree or because some quality of their genome makes them ideal to study. An example is the puffer fish (Fugu Rubripes) which has a similar gene repertoire to humans but a much smaller genome (400 million base pairs instead of 3000 million).
ADVANTAGES OF USING MODEL ORGANISMS:
In classrooms, Model Organisms are widely used to demonstrate to students important concepts in various disciplines. This method of teaching is effective in that the information relayed to these students is done so in a fun and productive manner. There are three main advantages:
1) In a laboratory setting, the model organism’s immediate response to the change of environment will enhance students’ learning and serve to hold their attention and interest.
2) Secondly, the use of model organisms involves hands-on activities that provide a unique experience that could not be obtained with other teaching methods.
3)Thirdly, by working with model organisms, students are able to explore scientific methods and concepts themselves. Moreover, they will come to understand about the investigative nature of the scientific enterprise, including how conclusions are drawn from data.