1. Chi-Square Analysis of Cells in Mitosis Cards

2. Chi-Square (χ2) Test
Use the Chi-Square Test to compare the cells shown on the onion cell cards vs. the textbook-given information (cell cycle model)
Null hypothesis: There is NO significant difference between the textbook values & observed data from onion cells
Any differences are due to CHANCE alone

3. Observed Data Count onion cells on your card. # Interphase: # Mitosis:
Class Data:
Interphase:
Mitosis:
Total # Cells:

4. Expected Data
The textbook model of the cell cycle says that 90% of the cell cycle is spent in Interphase.
Calculate expected # cells:
Total # Cells:
Interphase:
Mitosis:

5. Calculations Category Expected (Textbook values) Observed
(Cells on cards)
(o-e)2/e
Interphase
Mitosis
TOTAL:
X2 =

6. Chi-Square Analysis n = ______ Χ2 = _______ df = n-1 = _______
At p=0.05, the critical value is ________.
Conclusion:
The Χ2 value is _________ than the critical value, therefore the null hypothesis is _____________.
Any difference between observed an expected data is _______________________.