Conducting trials directly on humans is forbidden on humanitarian grounds. Since the human body is very complex direct involvement of humans as subjects of experiments may not always be possible. Therefore it is ideal to use prokaryotes, eukaryotes, and organisms other than humans. These helper organisms are known as model organisms. They contribute to scientific and industrial research. These organisms include bacteria, fungi, viruses, algae, nematodes, worms, and higher animals. Model organisms are selected based on criteria such as their ease of growing, short life cycle, well-defined cellular structures, easily analyzable properties, safe and ethically sound. Using hazardous toxin-producing bacteria or organisms for conducting experiments is forbidden and is accessed only in rare and unavoidable cases. Only trained, well-qualified professionals handle these organisms. Model organisms are involved in genome analysis, recombination experiments and sequence similarity studies. It requires a lot of care and caution to handle these organisms. Recombinant vaccines, peptides, and biomolecules are produced using model organisms. Biosatellites and spaceships use model organisms in their first launch.