al., 2007; Watson et al., 2004).
communication skills, and ability to synthesize
ideas and apply understanding to a new situation.
13
Implementing the Module
Cell Biology and Cancer
An assessment icon and an annotation
recognize the importance of distinguishing
that describes the aspect of learning you
factual information from opinions.
can assess using a particular strategy
• Keep the discussion relevant and moving
appear in the margin beside the
forward by questioning or posing appropriate
step in which each embedded assessment occurs.
problems or hypothetical situations. Encourage
everyone to contribute, but do not force
How Can Controversial Topics Be
reluctant students into the discussion.
Handled in the Classroom?
• Emphasize that everyone must be open to
Teachers sometimes feel that the discussion of
hearing and considering diverse views.
values is inappropriate in the science classroom or
• Use unbiased questioning to help students
that it detracts from the learning of “real” science.
critically examine all views presented.
The lessons in this module, however, are based
• Allow for the discussion of all feelings
on the conviction that there is much to be gained
and opinions.
by involving students in analyzing issues of
• Avoid seeking consensus on all issues.
science, technology, and society. Society expects
The multifaceted issues that the students
all citizens to participate in the democratic
discuss result in the presentation of
process, and our educational system must provide
divergent views, and students should
opportunities for students to learn to deal with
learn that this is acceptable.
contentious issues with civility, objectivity, and
• Keep your own views out of the discussion.
fairness. Likewise, students need to learn that
If your students ask what you think, you may
science intersects with life in many ways.
wish to respond with a statement such as,
“My personal opinion is not important here.
In this module, students have a variety of
We want to consider your views.”
opportunities to discuss, interpret, and evaluate
• Acknowledge all contributions in the same
basic science and public health issues in the light
evenhanded manner. If the class senses that
of values and ethics. Many issues that students
you favor one idea over another, you will
will encounter—especially those having to do with
inhibit open debate and discussion. For
public policies that force people to protect themselves
example, avoid praising the substance or
from agents known to cause cancer—are potentially
content of comments. Instead, acknowledge
controversial. How much controversy develops
the willingness of students to contribute by
will depend on many factors, such as how similar
making comments such as, “Thanks for that
your students are with respect to socioeconomic
idea” or “Thanks for those comments.” As you
status, perspectives, value systems, and religious
display an open attitude, a similarly accepting
preferences. It will also depend on how you
climate will begin to develop within the class.
handle your role as facilitator. Your language
• Create a sense of freedom in the classroom.
and attitude factor into the flow of ideas and
Remind students, however, that freedom implies
the quality of exchange among the students.
the responsibility to exercise that freedom in
ways that generate positive results for all.
The following guidelines may help you think
• Insist on a nonhostile environment in the
about how to guide your students in discussions
classroom. Help your students learn to
that balance factual information with values.
respond to ideas instead of to the individuals
• Neutrality may be the single most important
presenting those ideas.
characteristic of a successful discussion facilitator.
• Respect silence. Reflective discussions are often
• Encourage your students to discover as much
slow. If you break the silence, your students
information about the issue as possible. Ask
may allow you to dominate the discussion.
questions that help your students distinguish
• Finally, at the end of the discussion, ask
between those components of an idea or issue
your students to summarize the points
that scientific research can answer and those
they and their classmates have made.
that are a matter of values. Students should
Let students know that your respect for
understand the importance of accurate
them does not depend on their opinion
information to any discussion and should
about any controversial issue.
14
Using the Student Lessons
The heart of this module is the set of five lessons,
Procedure outlines the lesson’s steps and provides
which we hope will carry important concepts
implementation suggestions and answers to
related to cancer and personal and public health
questions. Annotations in the margins, identified
to your students. To review the concepts in
by icons, provide specific hints about
detail, refer to Table 1 in Implementing the
Module (page 5).
helping students see connections
between basic science and personal
Format of the Lessons
and public health,
As you scan the lessons, you will find that each
contains several major features.
assessing student understanding,
and
At a Glance gives you a convenient overview of
the lesson.
• The Overview provides a short summary of
focusing students’ attention on the
what students do.
lesson’s major concepts during its
• Major Concepts states the central idea the
closing steps.
lesson is designed to convey.
• Objectives list three to five specific
understandings or abilities students should
Other icons indicate
have after completing the lesson.
• Prerequisite Knowledge alerts you to the
when to use the Web site (see “Using
understandings and skills students should have
the Web Site” for instructions; a
before beginning the lesson.
print-based alternative is provided
• The Basic Science–Health Connection
for classes that don’t have access to
describes how the lesson illustrates the
the Internet) and
relationship between basic science and personal
and public health. The mission of NIH is
the beginning of a print-based
to “uncover new knowledge that will lead
alternative version of that step
to better health for everyone.” This mission
or activity.
statement recognizes that basic science and
personal and public health are not separate
issues; they are not even two sides of one issue.
Potential Extensions describes ways you can
Rather, they are inextricably linked and form
extend or enrich the lesson.
a powerful whole: Research into the basic
processes of life leads inevitably to strategies
All the Masters required to teach the lessons are
for improving health, and questions about
in a separate section at the end of the module.
health trigger research into basic processes.
• The Introduction places the lesson in a context
Lessons 2, 3, and 5 use materials on the Cell
and provides a short overview of its key
Biology and Cancer Web site. For information
components.
about the site, see “Using the Web Site” on
page 17. If you do not have enough computers
In Advance provides instructions for collecting the
with Internet access, you can use the print-
materials, photocopying, and other preparations
based alternatives.
needed for the activities in the lesson.
15
Cell Biology and Cancer
Timeline for Teaching the Module
teaching the module. Instructions for setting
The suggested timeline (Table 7) outlines a plan
up computers are under “Using the Web Site”
for completing the five lessons. The plan assumes
(page 17) and online at http://science.education.
you will teach the lessons on consecutive days
nih.gov/supplements/nih1/cancer/teacher and for and that class periods are 45 to 50 minutes
preparing other materials, under In Advance in
long. It’s important to review the timeline before
each lesson.
Table 7. Suggested timeline for teaching the module.
Timeline
Activity
4 weeks ahead
Order laboratory materials for Lesson 4.
(Optional) Reserve computer and bookmark the Web site.
1 week ahead
Copy masters and make transparencies, collect supplies.
Prepare yeast-extract dextrose (YED) plates.
Day 1
Lesson 1
Day 2
Lesson 2
Day 3
Lesson 3; streak YED plates (Lesson 3 could take up to 90 minutes)
Day 4
Lesson 4, Day 1
Day 5
Lesson 4, Day 2
Day 6
Lesson 5
16
Using the Web Site
The Web component of Cell Biology and Cancer
• offer unique instructional capabilities that allow
is a wonderful tool that you can use to help
students to explore topics in greater depth—
organize your use of the module, engage student
technology offers experiences that are closer
interest in learning, and help orchestrate and
to actual life than print-based media offer
individualize instruction. The site features
(the reference database that supports Lesson 5
simulations, illustrations, and videos that articulate
has this effect);
with the lessons. To access the curriculum’s
• support you in experimenting with new
home page, go to http://science.education.nih.gov/
instructional approaches that allow students
supplements/cancer/teacher. (If your classes don’t to work independently or in small groups—
have access to the Internet, you can use the print
technology gives teachers increased credibility
alternatives included with the lessons.)
among today’s technology-literate students; and
• increase your productivity—technology helps
The Web site includes the following resources:
teachers with assessment, record keeping, and
• information about the National Institutes of
classroom planning and management.
Health and National Cancer Institute;
• printable files of this module;
The ideal use of the Web site requires one computer
• printable files of the print-based alternatives
for each student group. However, if you have only
for Lessons 2, 3, and 5;
one computer available, you can still use the site.
• animations about cancer and video clips for
For example, you can use a projection system to
Lesson 2;
display the monitor image for the whole class. If
• a simulation for Lesson 3; and
you do not have access to the Web site, you can
• video clips and a reference database required to
use the print-based alternative provided for each
complete Lesson 5.
Web activity.
Hardware and Software Requirements
Collaborative Groups
The Web site can be accessed with any computer
We designed all the activities in this module to be
browser. Adobe Flash Player should be installed
completed by groups of students working together.
on the hard drive of each computer that will
Although individual students working alone can
access the site. It’s freely available at
complete many of the steps, this strategy will not
http://get.adobe.com/flashplayer/.
stimulate the types of student-student interactions
that are part of active, collaborative, inquiry-
Getting the Most Out of the Web Site
based learning. Therefore, we recommend that
Before you use this or any other piece of
you organize collaborative groups of two to four
instructional software in your classroom, it may
students each, depending on the number of
be valuable to identify some of the benefits you
computers available. Students in groups larger
expect the software to provide. Well-designed
than this are likely to have difficulty organizing
instructional multimedia software can
the student-computer interactions equitably. This
• motivate students by helping them enjoy
can lead to one or two students’ assuming the
learning—students want to learn more when
primary responsibility for the computer-based
content that otherwise might be uninteresting
work. Although large groups can be efficient, they
is enlivened (the video clips on the Web site
do not allow all students to experience the in-depth
offer students this benefit).
discovery and analysis that the Web site was
designed to stimulate. Group members not involved
directly may become bored or disinterested.
17
Cell Biology and Cancer
We recommend that you keep your students
State Standards Alignment
in the same collaborative groups for all the
To find out how this supplement’s content
activities. This will allow each group to
aligns with your state’s science, English language
develop a shared experience with the Web site
arts, and math education standards, go to
and with the ideas and issues the activities
http://science.education.nih.gov/StateStandards.
present. A shared experience will also enhance
your students’ perceptions of the lessons as
Web Materials for People
a conceptual whole. This will be particularly
with Disabilities
important in the activities toward the end of the
The Office of Science Education (OSE) provides
module, as students consider some of the ethical
access to the Curriculum Supplement Series for
and logistical complexities associated with our
people with disabilities. The online versions
growing knowledge about cancer.
of this series comply with Section 508 of the
Rehabilitation Act. If you use assistive technology
If your student-to-computer ratio is greater than
(such as a Braille reader or a screen reader) and
six students to one computer, you will need to
have trouble accessing any materials on our Web
change the way you teach the module from the
site, please let us know. We’ll need a description
instructions in the lessons. For example, if you
of the problem, the format in which you would
have only one computer available, you may want
like to receive the material, the Web address
students to complete the Web-based work over an
of the requested material, and your contact
extended time period. You can do this several
information.
ways. The most practical one is to use your
computer as a center along with several other
Contact us at
centers at which students complete other activities.
supplements@science.education.nih.gov
In this approach, students rotate through the
or
computer center, eventually completing the
(301) 402-2469
Web-based work you have assigned.
A second way to structure the lessons if you only
have one computer available is to use a projection
system to display the computer monitor onto
a screen for the whole class to see. Giving
selected students in the class the opportunity
to manipulate the Web activities in response to
suggestions and requests from the class can give
students some of the same autonomy in their
learning they would have gained from working
in small groups.
18
Understanding Cancer
Cancer is a term used for diseases in which
(a condition called in situ cancer). However, one
abnormal cells divide without control and are
of the central characteristics of a cancer cell is its
able to invade other tissues. There are more than
ability to invade nearby tissue and spread to other
100 different types of cancer. Cancer is a disease
parts of the body.
caused by genetic changes that develop over time.
Although cancer can develop in virtually any of the
Cancers can spread throughout the body by two
body’s tissues and each type of cancer has its
mechanisms: invasion and metastasis. Invasion
unique features, the basic processes that produce
refers to the direct migration and penetration by
cancer are quite similar in all forms of the disease.
cancer cells into neighboring tissues. Metastasis
refers to the ability of cancer cells to penetrate
Cancer begins when a cell breaks free of the
into lymphatic and blood vessels, circulate through
normal restraints on cell division and begins to
the bloodstream, and then invade normal tissues
follow its own agenda for proliferation (Figure
elsewhere in the body. Malignant tumors are
2). All the cells produced by division of this
capable of spreading by invasion and metastasis,
first, ancestral cell and its progeny also display
and, by definition, the term “cancer” applies
inappropriate proliferation. A tumor, or mass
only to malignant tumors. Tumors threaten an
of cells, formed of these abnormal cells may
individual’s life when their growth disrupts the
remain within the tissue in which it originated
tissues and organs needed for survival.
Figure 2. The stages of tumor development. A malignant tumor develops over time, as shown in this diagram.
A. The tumor begins to develop when a single cell’s DNA becomes altered, or mutated. We do not know the exact number of mutations required for a normal cell to become a fully malignant cell, but it is probably fewer than 10. The accumulation of mutations can transform a normal cell into a cancerous one. B. The altered cell and its descendants grow and divide rapidly, resulting in a condition cal ed hyperplasia. At some point, one of these cel s experiences another mutation that further increases its tendency to divide. C. This cell’s descendants divide excessively and look abnormal, a condition called dysplasia. As time passes, one of the cells experiences yet another mutation. D. This cell and its descendants are very abnormal in both growth and appearance. If the tumor that has formed from these cells is still contained within its tissue of origin, it is called in situ, or stage 0, cancer. In situ cancer may remain contained indefinitely. E. If some cells experience additional mutations that allow the tumor to invade neighboring tissues and to shed cells into the blood or lymph, the tumor is said to be malignant. The escaped cells may establish new tumors (metastases) at other locations in the body.
19
Cell Biology and Cancer
What happens to cause a cell to become
between different populations. For example, in
cancerous? Forty years ago, scientists could not
1775, an extraordinarily high incidence of scrotal
offer a coherent answer to this question. They
cancer was described among men who worked as
knew that cancer arose from cells that began to
chimney sweeps as boys. In the mid-1800s, lung
proliferate uncontrollably within the body, and
cancer was observed at alarmingly high rates
they knew that chemicals, radiation, and viruses
among pitchblende miners in Germany. By the
could trigger this change. But exactly how it
end of the 19th century, using snuff and cigars
happened was a mystery.
was thought by some physicians to be closely
associated with cancers of the mouth and throat.
Research across the past three to four decades,
however, has revolutionized our understanding
These observations and others suggested that
of cancer. In large part, this success was made
the origin or causes of cancer may lie outside
possible by the development and application of
the body and, more important, that cancer could
the techniques of molecular biology, techniques
be linked to identifiable and even preventable
that enabled researchers to probe and describe
causes. These ideas led to a widespread search
features of individual cells in ways unimaginable
for agents that might cause cancer. One early
a century ago. Today, we know that cancer is a
notion, prompted by the discovery that bacteria
disease of molecules and genes, and we have
cause a variety of important human diseases,
even identified many of the molecules and genes
was that cancer is an infectious disease. Another
involved. In fact, our increasing understanding of
idea was that cancer arises from the chronic
these genes is making possible the development
irritation of tissues. This view received strong