A plant breeder crosses a tomato plant heterozygous for two genes (DdPpDdPpDdPp) with a double homozygous recessive plant (ddppddppddpp). They expect a phenotypic ratio of 1:1:1:1 1:1:1:1\,1:1:1:1 in the offspring.
From 400 offspring, the observed phenotypes are:
Using a Chi-squared (χ2\chi^2χ2) test at the p=0.05p = 0.05p=0.05 significance level (where the critical value for 3 degrees of freedom is 7.81), which of the following represents the correct calculated value of χ2 \chi^2\,χ2 and the correct biological conclusion?
Calculated χ2=2.50\chi^2 = 2.50χ2=2.50; there is no significant difference between observed and expected ratios.
Calculated χ2=2.50\chi^2 = 2.50χ2=2.50; there is a significant difference between observed and expected ratios.
Calculated χ2=0.30\chi^2 = 0.30χ2=0.30; there is no significant difference between observed and expected ratios.
Calculated χ2=250.00\chi^2 = 250.00χ2=250.00; there is a significant difference between observed and expected ratios.
