Answer:
Long life span
Explanation:
A model organism is a non human specie that is used for study in order to understand a particular biological phenomena.
One of the qualities of a model organism is that; It should have a short life span this will make it more amenable to experimental manipulation due to short generational time. Therefor Long life span will not be a desirable characteristic.
Other desirable characteristic includes ease of growth and production of many offsprings.
Also common genetic mechanism with other organisms, they should share some degree relatedness.
