MITOSIS LABORATORY – MICROVIEWER 55
1. The following eight microviewer slides show the photographs taken from a single
____________________________. The cells were taken from the rapidly dividing region
called the “meristem”.
2. Go to Slide #1, find cell “A” that is in the resting stage called ____________________.
a) Name 2 important events that occur during
Interphase.
_____________________________________
_____________________________________
b) Describe what the nucleus looks like.
c) Label the following organelles: nuclear
membrane, nucleolus, cell wall, cytoplasm
3. Go to Slide #2, locate the cell in the middle that is undergoing the second stage of
the cell cycle called _______________________.
a) Are chromosomes now visible during
prophase?
b) What has happened to the genetic
material to make them clearly visible
inside the nucleus?
c) Describe the changes that have
occurred to inside the nucleus (i.e.
nucleolus & nuclear membrane).
d) What features allow you to identify this cell as a plant cell and not an animal
cell?
4. Go to Slide #3, locate cell “C” that has reached
the middle stage of mitosis called
_____________________________.
a) Describe where the chromosomes are now
located in relation to the cell.
b) Can evidence of chromosome duplication be
observed now? Explain the appearance of the
chromosomes.
c) What are the fibres called that become visible
during this phase?
5. Go to Slide #6, locate cell “F” that is the late stages of ______________________.
a) Describe what is occurring to each chromosome during anaphase.
b) What term is given to the genetic material during
this phase? ____________________________________
What letter of the alphabet does it resemble? ____
c) Toward what area of the cell are chromosomes
being directed? _____________________________
d) What structure is responsible for the movement
of chromosomes during this phase?
6. Go to Slide #7, locate cell “G” that is in the last stage of mitosis called ___________.
a) There are _____ sets of chromosomes that
are tightly forming a dense mass at each
________. Each of these mass will eventually
become the ________________ of the cell.
b) What cell parts begin to reappear during
this phase?
c) What cell parts begin to disappear during
this phase?
7. Then look at Slide #8, locate cells “H” which
shows late ________________ and the two
genetically _________________ daughter cells.
a) How many cells have now formed from the
original cell?
b) The daughter cells are genetically
(identical/different) from each other. (Circle one)
c) Once the cell finishes telophase, it will then
enter this next phase of the cell cycle
__________________.
d) In order to form 2 fully independent cells, what structure/organelle must be
formed between the two daughter cells? ______________________
Part B – Determining the Rate of Cell Division (Onion Root Tip)
1
3
2
5
4
7
6
8
9
10
11
12
a) For each of the following cells from (1 to 12), identify the stage of the cell cycle.
1 ______________________________
7 ____________________________
2 ______________________________
8 ____________________________
3 ______________________________
9 ____________________________
4 ______________________________
10 ____________________________
5 ______________________________
11 ____________________________
6 ______________________________
12 ____________________________
b) Majority of the cells are found in this stage of the cell cycle: __________________
c) Is this a realistic portrayal of an onion root tip? Explain.
DETERMINING THE RATE OF CELL DIVISION
PURPOSE: to identify different stages within the cell cycle and to observe changes in
the genetic material as it undergoes mitosis.
MATERIALS: microscope, prepared slides of onion root tip (Allium) longitudinal
section, microviewer, microviewer slide (Plant Mitosis – Set 55)
PROCEDURE – Microscope & Slide
1. Locate with a microscope the region of
rapidly dividing cells on the prepared
slide of the onion root tip, as shown in
Figure 15-1.
2. After locating the cells under low power,
switch to medium & then high power.
*Note: make sure that the specimen is
well-focused before changing
magnification.
3. Count 20 cells that are next to one another in the onion root tip. Determine which
of those cells are dividing (i.e. mitosis).
4. Complete the chart below by recording the number of cells you found in each
phase of the cell cycle. Use the diagrams below to help you identify each stage.
Phase
Number of Cells
*Percentage of total in
phase
**Pie Graph
(degree)
20
100%
360o
Interphase
Prophase
Metaphase
Anaphase
Telophase
TOTAL
*to calculate percentage total, take the number of cells divide by 20 and multiply by 100.
**to calculate degree for pie graph, change the percent into a decimal place and multiply by 360.
INTERPHASE
PROPHASE
METAPHASE
ANAPHASE
TELOPHASE
5. Using the pie graph below, indicate how much of each phase takes up the entire
cell cycle. *Note: you will need a protractor to help you graph your information.
Make sure to include a legend and colour code each phase of the cell cycle.
Analysis Questions:
a) What stage/phase were the
majority of the cells in?
b) Is your data accurate with the
actual cell cycle? Explain.