A geneticist crosses a fruit fly (Drosophila melanogaster) heterozygous for two independent genes with a double homozygous recessive partner.
They expect a 1:1:1:1 1:1:1:1\,1:1:1:1 phenotypic ratio in the offspring.
Out of 600 offspring collected, 162 are wild-type, 142 have vestigial wings, 155 have ebony bodies, and 141 have both mutations.
Which of the following is the statistical test that should be used to determine if these observed numbers are significantly different from the expected 1:1:1:1 1:1:1:1\,1:1:1:1 ratio?
Student's ttt-test
Spearman's rank correlation
Chi-squared (χ2\chi^2χ2) test
Standard deviation