Genetic problems a researcher studying petunia plants. these plants have either red or white and this characteristic is influenced by one gene. the alleles are r red (red is dominant) and r white. she crosses to heterozygous red plant with a homozygous white plant. determine the expected genotypes and phenotypes of the offspring using the steps outlined above.

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.