Animal Mitosis under the Microscope
Observations
1. Observe the slide under low power and then medium power. How can you tell the
cells are dividing?
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2. Observe the slide under high power. Locate and observe cells in each of the phases
of mitosis.
a) Draw a cell in each of the four phases of mitosis (prophase, metaphase,
anaphase, and telophase). Create a diagram of each phase of mitosis using
your word processor or other software. A number of options are available for
submitting your file. Ask your teacher if s/he can read the file format you want to
use to create the file. If you do not have software for creating the drawing, you
may hand draw it. Enlarge your drawing and draw what you see. You will submit
a photograph or a scan of your drawings.
b) Label the chromosomes, nuclear membrane, nucleolus, spindle fibres, and cell
membrane if they are visible.
c) Write a brief description for each of the phases. Refer to the images you have
seen on mitosis and the resource section of this assignment for assistance.
prophase
description:__ the cell is preparing for
division_______________________
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metaphase
description:__ the second stage of mitosis,
the chromosomes line up across the
middle of the cell where the spindle fibres
attach to the chromosomes and begin to
pull them
apart._______________________
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anaphase
description:____ can easily be
remembered because the identical halves
of each chromosome are pulled apart to
opposite ends of the cell by the spindle
fibres._____________________
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telophase
description:_ The chromosomes reach
opposite poles and the spindle fibres
disappear. A new nuclear membrane
begins to appear around the
chromosomes and the cell begins to pinch
inwards to show two separate
cells.________________________
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3. While observing the slide under high power, count the number of cells seen in
interphase and each of the phases of mitosis.
interphase
prophase
metaphase anaphase
telophase
IIIIIIIIII
IIIII
IIIIIIIII
III
II
10
5
9
3
2
Tally
Total
number of
cells
Discussion: Answer the following questions in complete sentences and in your
own words.
1. Why is the whitefish blastula used for viewing mitosis?
2. Explain why the cells you observed are not dividing at this time?
3. Calculate the percentage of cells that are in each of the phases: interphase,
prophase, metaphase, anaphase, and telophase. Use the data you collected on
the total number of cells in each phase. Show all calculations.
Interphase:
You counted 30 cells in total the field of the microscope.
10 out of the 30 cells counted were in interphase.
Per cent = 10/30 X 100
= 33 %
4. The percentage of cells in each phase represents the time spent in each of these
phases. Which phase has the highest percentage of cells and therefore
represents the longest time the cell spends in this stage?