Agriculturalists investigating a poorly growing onion crop discovered it was infected with a fungal pathogen. The fungus secreted a lectin-like protein in the soil surrounding the onions’ roots. Lectins often accelerate mitosis in root systems, but this abnormal growth creates weaker plant tissues. Fifty cell samples were observed for the struggling onion crop. The observed number of cells in each part of the cell cycle are shown below: Interphase Mitosis
Sample One 21 29
Sample Two 18 32
Sample Three 25 25

a) State the null and alternative hypothesis related to the data.
b) Calculate the chi-square values for interphase and mitosis using the samples as the observed values (o) and trial 1 in table 3 as your expected data (e).

c) Using the chi-square table, determine the critical value for interphase and mitosis of the struggling onion crop using the chi-square values in (b).

p-
value Degrees of Freedom
1 2 3 4 5 6 7 8
0.05 3.84 5.99 7.82 9.49 11.07 12.59 14.07 15.11
0.01 6.64 9.21 11.34 13.28 15.09 16.81 18.48 20.09

d) Based on the chi-square and critical value, draw a conclusion about the null hypothesis.