Name
Period
The Cell Cycle & Mitosis Tutorial
DNA BASICS
To view the tutorial, type in the URL:
http://www.biology.arizona.edu/cell_bio/tutorials/cell_cycle/cells1.html
1. Read, “What is DNA and Where is it Stored”
2. Answer the following questions.
a. Which organelle contains DNA?
b. What is DNA called, or in the form of, when in the nucleus?
c. When cells divide, DNA is called what?
alphabet letter
.
d. A nucleosome is DNA wrapped around a
they appear as “beads on a string.”
It looks like the
, and
e. The process of mitosis is designed to insure that
are passed on to daughter cells.
3. Click “Next” at the bottom of the page.
THE CELL CYCLE
4. Read the introductory page, “Stages of the Cell Cycle.”
5. Answer the following questions:
a. List the stages of the cell cycle beginning with G1.
b. What occurs during the “S” phase?
c. What occurs during the “M” phase?
d. Complete the following sentence. “Cancer is a disease where
.”
6. Click “Next” at the bottom of the page.
1
MITOSIS
7. Read “What is (and is not) mitosis?”
8. Answer the following questions:
a. Interphase encompasses which stages of the cell cycle?
b. What is the purpose of mitosis?
9. Mitosis has 4 main stages. Fill in the blank for each phase:
INTERPHASE
PROPHASE
METAPHASE
ANAPHASE
Interphase: The cell is engaged in _________________________ and performing
its preparation for _______________.
Prophase: Chromatin condenses and becomes visible as
. Centrioles begin moving to
fibers extend from the
. The
disappears.
Metaphase: Spindle fibers align the
along the middle of the cell and this line is called the
of the cell and
chromosomes
.
Anaphase: The paired chromosomes separate and move to
.
TELOPHASE
Telophase:
The
arrive at opposites poles of the cell.
disperse. Cytokinesis may also
during this phase.
CYTOKINESIS
9. Cytokinesis: In animal cells, the center of the cell pinches into
. In plant cells, a
is synthesized
between the two daughter cells.
2
Online Onion Root Tips – A Virtual Lab Exercise
The following activity is designed to test your ability in identifying the stages of mitosis in onion root
cells. To access this activity, type in the URL below:
http://www.biology.arizona.edu/cell_bio/activities/cell_cycle/cell_cycle.html
1. Read the introduction on the first page then click “Next”.
2. Review the stages of mitosis on this page, paying particular attention to the pictures on the left
side of the screen. When you are finished, click “Next”.
3. On the Activity page, you will be presented with cells from the tip of an onion root. You will
classify each cell based on what phase of mitosis it is in. At the end, you will count up the cells
found in each phase and use those numbers to predict how much time a dividing cell spends in
each phase.
4. Before you begin the activity, make a prediction:
In what stage of the cell cycle will you find the majority of cells? Why?
5. Begin the activity by following the directions given to you on the screen. When you are finished
classifying the phase of each cell, and complete the table below:
INTERPHASE PROPHASE METAPHASE ANAPHASE TELOPHASE
# of
cells
% of
cells
TOTAL
36
100%
6. Using your data, during which phase will the cell spend most of its time? Why?
3