Suppose that for a certain gene, nearly 100 percent of the normal level of expression is required to produce the normal phenotype. Based on this requirement, one could predict that a mutation would be .

In an experiment examining the effects tai chi on arthritis pain, callahan (2010) selected a large sample of individuals with doctor-diagnosed arthritis. half of the participants immediately began a tai chi course and the other half (the control group) waited 8 weeks before beginning. at the end of 8 weeks, the individuals who had experienced tai chi had less arthritis pain that those who had not participated in the course.