Download Mitosis Analysis

Mitosis Analysis
Onion Root Tip
Name _____________________________________________ Period _________ Date ________________________
In this activity, you will be able to:
• Identify cells in the various phases of its life cycle, including the phases of mitosis.
• Determine the percentage of time cells spend in each phase of its life cycle.
Part 1: Identify the phases of mitosis in plant cells
1. Look at the arrows in each box below.
2. Write the correct name of the phase of mitosis in the box next to each picture.
3. Explain how you can tell it is that phase in the last box (hint: telophase and
cytokinesis are combined into one phase).
Picture
© 2010 K.Corbett
Phase
How can you tell?
Part 2: Calculate the percentage of time spent in each phase.
1. Use the image above to count the number of cells in each phase of its life cycle.
Record your answer in the table below.
2. Count the number of cells in each phase. Record your answers in the table below.
Hint: count the cells for prophase, metaphase, anaphase, and telophase/cytokinesis.
Whatever is left over from the total is the number of cells in interphase.
3. Calculate the percentage of time these cells spend in each phase by dividing the
number of cells in that phase by the total number of cells and report your answer as a
percentage in the table below.
Phase
Total number of cells
Prophase
Metaphase
Anaphase
Telophase/cytokinesis
Interphase
© 2010 K.Corbett
Number of cells
Percentage of cells
----- n/a -----
Part 3: Pie chart of cell life cycle
1. Make a pie chart showing the percentage of time the onion root tip cell spends in
each phase of its life cycle. Put all of the mitosis phases in order next to each other
in the pie chart.
Part 4: Observe the onion root tip under the microscope.
1. Look at an onion root tip under the microscope. Find a cell that is undergoing a step
of mitosis. Draw it using high power on the microscope in one of the circles below.
Find another cell undergoing a different phase of mitosis. Draw it in the second cell
using high power. Find a third cell undergoing a different phase of mitosis and draw
it in the third circle using high power. Label the phase in each drawing.
© 2010 K.Corbett
Part 5: Conclusions
1. Which phase has the highest percentage of time spent in that phase? Why?
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2. How does the picture on page 2 of this lab show that mitosis is a continuous process
and not a series of separate events?
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3. The onion plant began as a single cell. It had “X” number of chromosomes (the exact
number isn’t important, we’ll just call it “X”). How many chromosomes are in each
of the cells you observed (give your answer in terms of “X”)? How do you know?
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4. Summarize what you learned in this lab.
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© 2010 K.Corbett