Explanation:
A model is used to help scientists visualise things that they cannot actually see. It can be thought of as a thinking tool, to help form explanations. Models are useful simplifications to aid understanding. ... It can then be used to explain further phenomena and to make predictions of future behaviour.
They would kill the rest of the cells
The second one would be my answer but also an answer that is not up there is that during an experiment when repeating the trials you might have to set up a new hypothesis every time and have to review the data several different times because of different results from each trial
hope this helps if not just let me know