Online Onion Root Tips
Name ___________________
Date ___________________
Period __________________
Go to:
http://www.biology.arizona.edu/cell_bio/activities/cell_cycle/cell_cycle.html
In this computer simulation, we will explore the different phases of the Cell Cycle. Begin by
reading through the introduction. Answer the following pre-lab questions from the
introduction.
Pre-Lab Questions
1. In plants, why do roots continuously grow?
2. Why is this region a good one to study?
3. Why are the onion cells stained in the pictures?
4. As you watched the animated cell divide, what do you notice about the changing size of
the cell as it divides?
5. Name the 4 phases of mitosis and briefly summarize what is happening in each one?
Now you are ready to begin the simulation!
Use the Next at the bottom of the page when you have completed the pre-lab questions and
are ready to do the simulation. If you need to go back to the previous page, click on the
Previous button.
Once you decide in what phase of the Cell Cycle the picture is, click on the highlighted
name of the phase and it will add it to the list. If you make a mistake, the computer will
give you some hints to help you figure out the correct phase, and will direct you to try
again. When you have classified all 36 cells, then you will need to scroll down to count how
many cells are in each phase and put the numbers in the data table below.
Data Table
Interphase
Prophase
Metaphase
Anaphase
Telophase
Total
number of cells
36
percent of cells
100
We can now figure the percent of cells in each phase of the cell cycle by doing this
calculation:
Number of Cells in each phase of the cell cycle X 100 = the percentage of cells in that phase
36
Repeat the calculation for each of the 5 phases of the cell cycle and enter the percentages in
the boxes in the data table.
Analysis Questions:
1. In which phase of the Cell Cycle did most of the cells belong?
2. Which phase had the least cells in it?
3. What do these percentages tell you about the time spent in each phase of the Cell Cycle?
4. How many cells are formed from the process of mitosis?
5. How many chromosomes do the daughter cells have, when compared to the parent cell?
6. Why is mitosis necessary for an organism?
What do we know about increasing the size of a cell?
7. How does the process of mitosis help the organism grow?
Online Onion Root Tips
Determining time spent in different phases of the cell cycle
Congratulations! Here comes the quantitative part of this experiment. Scroll
down this page and count up all of the cells in each category, and enter your
findings in the top row of your table.
Then, calculate the percentage of cells in each phase, and enter those
values on the bottom row of the table.
INTERPHASE PROPHASE METAPHASE ANAPHASE TELOPHASE
Vocabulary