What is a model system in biological research?

A model system in biological research refers to a species or organism that is used to study and understand biological phenomena. These organisms are chosen due to their particular characteristics that make them suitable for scientific investigation. For instance, model organisms often have well-mapped genomes, a short generation time, and robust laboratory breeding capabilities. Examples include fruit flies (Drosophila melanogaster), mice, and zebrafish. Researchers can use these systems to gain insights into complex biological processes that may also apply to other species, including humans.

The other options do not accurately capture the definition of a model system. While specific treatments and tools for genetic analysis are important aspects of biological research, they are not classified as model systems. Similarly, methods of calculating genetic probabilities pertain more to statistical tools used within the analysis rather than to a biological model itself.