What things McDonald's do not allow for their employee

what is the other part to the question

this null effect is caused by a weak manipulation and ineffective internal validity. in a scientific study, as the one dr. morimoto is trying to perfom, internal validity refers to the confidence placed in the cause-effect relationship and to how well an experiment is done and able to eliminate confounding variables.        

answer; the smaller of the two reciprocal products of translocated chromosomes is lost; after several cell divisions, only the larger of the two translocated chromosomes remains,its reciprocal is lost;