Download The Cell Cycle

Name________________________ Per_____
Ch. 5 CELL CYCLE STUDY GUIDE
 The Cell Cycle WS
 Stages of Mitosis WS
 Cancer Articles & Questions
DUE _______________
The Cell Cycle
Using page 130 in your textbook. Label and color the cell Cycle. Don’t forget to label the
arrow!
G1  S  G2  M  C
Explain what is happening during each phase.
G1 Phase =
Interphase
S Phase =
G2 Phase =
Cell Division
M (Mitosis) Phase =
C (Cytokinesis) Phase =
Name _________________________ Period ___
STAGES OF MITOSIS
Figure A shows 6 diagrams made during the cell cycle in an animal cell. Instructions:
1. Use the word bank provided to label the phases shown.
2. Number the pictures in order from 1 to 6.
3. Repeat the process for Figure B which shows 6 diagrams made during the
cell cycle in a plant cell.
Word Bank:
1
anaphase
cytokinesis
2
3
interphase
metaphase
4
5
prophase
telophase
6
How is mitosis different in plant cells compared to in animal cells?
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Matching:
Match the questions below with the proper answers that follow them. Write the
correct CAPITAL letter in the blank.
_______ 1. What is mitosis?
_______ 2. In order, what are the
four main stages of
mitosis?
_______ 3. What is the name of the
stage a cell goes through
just prior to mitosis?
_______ 4. What is the main event
of interphase?
_______ 5. What are two important
events of prophase?
_______ 6. What is the main event
of metaphase?
_______ 7. What structure is
involved in moving
chromosomes during
mitosis?
_______ 8. What is the main event
of anaphase?
_______ 9. What are two important
events of telophase?
_______ 10. At the completion of
mitosis when the cell
divides, what name is
given to the two new cells?
_______ 11. You began life as a onecelled structure called a
zygote. What process then
took place over and over
to build a body containing
billions of cells?
A. Interphase
B. The chromosomes in the nucleus
of the cell make identical copies
of themselves
C. The chromosomes move toward
and line up along the center of
the cell, called the equator.
D. The nuclear membrane
disappears and the
chromosomes become distinct.
E. Mitosis
F. New nuclear membranes form
around each of the two sets of
chromosomes, and the cell
divides into two daughter cells.
G. Prophase, metaphase, anaphase,
and telophase
H. Daughter cells
I. Microtubules
J. Division of the nucleus of the cell
(usually followed by division of
the cell itself)
K. The microtubules pull one set of
chromosomes to one side of the
cell and an identical set to the
opposite side of the cell
Understanding Cancer
This excerpt was taken from the Johnson & Raven Biology text.
Most healthy cells of the body grow, divide a
certain number of times, age, and die. Sometimes, this
orderly process is disrupted when cells lose the ability to
limit and direct their growth. Cells may divide too often
and produce an excess of cells, called a tumor. A tumor
can be benign or malignant. Benign tumors do not
spread to other parts of the body, and can usually be
surgically removed. A malignant tumor—cancer—
invades and destroys nearby healthy tissues and organs.
Cancerous tumors can metastasize, that is, can spread to
other parts of the body and form new tumors. There are
probably at least 100 different kinds of cancer; with each
one affecting different kinds of cells and having different
characteristics.
Cancer cells do not respond normally to the
chemical signals that regulate the cell cycle. In some
cancer cells, the way cell division signals are transmitted
to the nucleus is abnormal. In other cancer cells, the
entire cell cycle control system may be abnormal. If
cancer cells stop dividing, they do so at random points in
the cell cycle rather than at the normal checkpoints.
When cultured in the laboratory with adequate nutrients,
cancer cells can divide indefinitely and are referred to as
“immortal”. Most mammalian cells grown in culture divide
only 20 to 50 times before they stop dividing, age and die.
How Cancer Begins
Changes in the genes that influence the cell
cycle can cause the transformation of a normal cell into a
cancer cell. There are two types of these genes. The
first type codes for proteins that stimulate cell division.
Genes of this type are normally turned off in cells that are
not dividing. This type of gene can be converted to an
oncogene, that is, a “cancer gene,” by mutation. One
common oncogene, a gene called ras, is present in
mutated form in about 30 percent of human cancers and
in some forms of leukemia.
The second type of gene associated with cancer
is a tumor suppressor gene. Tumor suppressor genes
code for proteins that normally restrain cell division. In
many cancers, tumor suppressor genes have been
inactivated by mutation. An inherited mutation in one
copy of a tumor-suppressor gene results in higher risk of
cancer. However, cancer does not occur unless and until
the remaining, healthy copy of the gene is also
inactivated by mutation. If a person is born with two
normal copies of a tumor suppressor gene, both must be
inactivated before cancer can develop.
Almost 50 percent of human cancers are
associated with a mutation in the tumor suppressor gene
p53. These cancers include many breast, colon, lung,
prostate, and skin cancers. The protein produced by the
p53 gene normally acts as an emergency brake in the cell
cycle. The p53 protein also induces the death of
damaged cells. To perform these functions, p53 proteins
must bind to DNA. Mutant p53 protein cannot bind to
DNA, thus cell division occurs unchecked.
Mutations that result in cancer, whether they
involve oncogenes or tumor suppressor genes, can occur
spontaneously. Mutations can also be induced by factors
in the environment, such as X-rays and ultraviolet
radiation, cigarette smoke, asbestos, and even by the
human papilloma virus and the hepatitis B virus.
Surviving Cancer
In the United States, about one of every five
deaths—more than half a million each year—are caused
by cancer. Only heart disease kills more people. The
number of new cancer cases and the number of cancer
deaths for every 100,000 persons have decreased over
the past 10 years. The death rates for children and
adults under the age of 50 have decreased dramatically.
Some kinds of cancer kill more people than
others. Lung cancer is the number one cancer killer.
Colorectal cancer, breast cancer, and prostate cancer are
the next most common. Cancer survival is measured by
the percentage of cancer patients who survive a specific
number of years. Five-year cancer survival rates for
common cancers are shown in the table [below].
Cancer survival is influenced by the type of
cancer and by the stage at which a cancer is diagnosed.
For example, the 5-year survival rate for colorectal cancer
diagnosed in its first stage is 96 percent. When
diagnosed in its fourth and most advanced stage,
however, the 5-year survival rate is only 5 percent.
Cancer screenings and early detection of cancers, such
as those of the breast and colon, greatly increase a
person’s chances of surviving cancer.
Career – Cancer Treatment: Profile Oncologist
Oncologists are cancer specialists—physicians who care for
people who have been diagnosed with cancer.
Job Description
Oncologists may begin to treat a patient soon after he or
she is diagnosed with cancer. Oncologists work
cooperatively with surgeons, radiologists, and other
physicians to devise the best combination of treatments for
the particular patient and cancer being treated.
Oncologists may manage radiation treatment and/or
chemotherapy, as well as other types of cancer therapy.
Cancer Survival Rates
Cancer Site
5-year Survival Rate (%)
Prostate
98
Breast
88
Colorectal
63
Leukemia
47
Brain
32
Lung
15
Pancreas
4
All cancers
64
Science/Math Career Preparation
Biology
Chemistry
Genetics
Microbiology
Biochemistry
Mathematics
Questions:
1. What is a tumor? What is the difference between a benign tumor and a malignant
tumor?
2. What are the two types of cancer-causing genes that are discussed? Which one is
turned off when it causes cancer? Which one is turned on when it causes cancer?
3. Name 4 environmental factors that can cause cancer.
4. The article says that cancer is the second leading cause of death. According to the
article, what is the leading cause of death?
5. According to the 5-year survival rate chart, if 100 people got pancreatic cancer, how
many will still be alive after 5 years? If 100 people got breast cancer, how many would
be alive after 5 years?
6. Describe the common duties of an oncologist.