Models are the representative of the real world. A model system can provide information of the reactions going on inside a living system. A model should provide the following advantages which are: it should be easy to culture in lab., it should have a short life cycle, it should be inexpensive to operate, it should be easily genetically manipulated, it should be a representative of the original population, I should provide accurate result which might happen in the original population and it should provide economically important results etc. Model can include an organism or it can be a Computer based simulation.
If two different alleles for a trait are present and one allele doesn't entirely block the expression of the other, the genetic situation is in-complete Dominance
