The following 5 questions refer to the following scenario. a true breeding red eyed fly with long bristles was crossed to a true breeding white eyed fly with stubble bristles. all f1 progeny are red eyed with stubble bristles. an f1 female is crossed to a tester male and the following numbers of progeny are observed: 56 red eyed, stubble bristles; 72 red eyed, long bristles; 61 white eyed stubble bristles; and 68 white eyed, long bristles. you are asked to perform a chi-squared test for this result. what is the best null hypothesis for this test?