Mitosis Mix up activity
WATCH THIS FIRST:
Chi Square video link
Normal untreated Onion root tip
Now let’s look at a different case
You should have done this yesterday
• Complete the mitotic mix up activity chart
portion for both tissue samples
• Now we know what the normal percentage of
time a ORT cell spends in each stage of mitosis
• We should have a percentage of cells in each
stage for the caffeine treated and the
untreated cells
1/12:Step by step
1. Label a page in your lab notebook: the effects of
caffeine mitosis.
2. Do you think caffeine will effect the rate of
mitosis?
3. Let’s go with the null hypothesis.
4. Write the null hypothesis for this experiment in
your notebook.
5. Make sure you watched the video linked in the
first slide of this power point here it is again:
https://www.youtube.com/watch?v=WXPBoFDq
NVk
Observed Versus Expected
• Working from H0= Caffeine does not effect
the rate of mitosis in the root tip of onion
plants.
• Expected would be the normal
rates(percentages) of each stage of the cell
cycle
• Observed would be the percentages of cells in
each stage of the cell cycle after caffeine
treatment
Chi Square Chart
1. Indicate what you are counting in your
notebook. Describe your brief procedure :
briefly describe how you decided a cell was in
each stage
2. Create the chart below and fill it in
Stage
# observed # expected
(O)
(E)
(O-E)
(O-E)2
(O-E)2/E
Inter
Pro
Meta
Ana
Telo
X 2=
Make a conclusion
• Determine the degrees of freedom ( you have
5 groups of data because there are 5 stages)
• Use a critical value of .05
• Write a paragraph telling if you supported or
rejected your null hypothesis and why.
• Insert your mitosis mix up completed
• Turn this in for a major grade ( you may turn in
on Wednesday) If there are questions email
me
Chi Square chart