CELL CITY
Teacher’s Guide
INTRODUCTION
This Teacher’s Guide provides information to help you get the most out of Cell City. The contents
in this guide will allow you to prepare your students before using the program and present follow-up activities to reinforce the program’s key learning points.
The Cell City CD-ROM helps users understand the operation of a cell by revealing its similarities
to a city. Concepts such as energy generation and supply, manufacturing, communications,
waste disposal, and recycling are all clarified using this technique. The program includes animations, videos, microscopic photography, and interactive puzzles.
The program also allows students to view various types of cell organelles by integrating a large
collection of photographs, including photomicrographs taken with electron microscopes and
optical microscopes. Students can browse through these unique images, or extract them for use
in their own assignments or presentations. In addition to photomicrographs, there are some
remarkable images of everyday objects viewed at very high magnification.
A separate unit allows investigation of optical microscopes, and both scanning and electron
microscopes. This section examines the performance of the different types of microscope used to
look at cells, the basis of their operation, and typical results.
LEARNING OBJECTIVES
After viewing the program, students will…
■ Describe the structures and functions that are common to all cells and identify the differences
between various types of cells.
■ Explain the structures and functions of common cell organelles and how they work together
to sustain the cell.
■ Explain how the life functions of organisms are related to what occurs within the cell.
■ Understand that hereditary information is contained in the chromosomes of each cell and that
each chromosome is made up of long strands of DNA molecules.
■ Know cells divide to increase their numbers through the process of mitosis, which results in
two daughter cells with identical sets of chromosomes.
■ Understand the ability and value of various types of microscopes.
EDUCATIONAL STANDARDS
National Standards
This program correlates with the National Science Education Standards developed by the National
Academy of Sciences and Project 2061 Benchmarks for Science Literacy from the American
Association for the Advancement of Science. The content has been aligned with the following
educational standards and benchmarks from these organizations.
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Understands the cell.
Understands matter, energy, and organization in living systems.
Understands the molecular basis of heredity.
Understands the structure and function in living systems.
Understand that all living things are composed of cells, from just one to many millions, whose
details usually are visible only through a microscope. Different body tissues and organs are
made up of different kinds of cells. The cells in similar tissues and organs in other animals are
similar to those in human beings, but differ somewhat from cells found in plants.
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Copyright © 2004 Cambridge Educational ®
■ Understand that every cell is covered by a membrane that controls what can enter and leave
the cell. In all but quite primitive cells, a complex network of proteins provides organization
and shape and, for animal cells, movement.
■ Understand that cells repeatedly divide to make more cells for growth and repair. Various
organs and tissues function to serve the needs of cells for food, air, and waste removal.
■ Understand that within every cell are specialized parts for the transport of materials, energy
transfer, protein building, waste disposal, information feedback, and even movement. In addition, most cells in multi-cellular organisms perform some special functions that others do not.
■ Understand that within cells, many of the basic functions of organisms—such as extracting
energy from food and getting rid of waste—are carried out. The way in which cells function is
similar in all living organisms.
■ Understand that the work of the cell is carried out by the many different types of molecules it
assembles, mostly proteins. Protein molecules are long, usually folded chains made from 20
different kinds of amino-acid molecules. The function of each protein molecule depends on its
specific sequence of amino acids and the shape the chain takes is a consequence of attractions between the chain’s parts.
■ Understand that the genetic information encoded in DNA molecules provides instructions for
assembling protein molecules. The code used is virtually the same for all life forms. Before a
cell divides, the instructions are duplicated so that each of the two new cells gets all the necessary information for carrying on.
Reprinted with permission from National Science Education Standards ©1999 by the National Academy of Sciences,
courtesy of the National Academies Press, Washington, D.C.
From BENCHMARKS FOR SCIENCE LITERACY by the American Association for the Advancement of Science, copyright 1993 by the American Association for the Advancement of Science. Used by permission of Oxford University
Press, Inc. Please note: judgments about the alignment of content presented here with the learning goals in BENCHMARKS FOR SCIENCE LITERACY are those of the author and do not represent the opinion or endorsement of the
AAAS or Oxford University Press, Inc.
English Language Arts Standards
The activities in this Teacher’s Guide were created in compliance with the following National
Standards for the English Language Arts from the National Council of Teachers of English.
■ Knowledge of language structure, language conventions (e.g., spelling and punctuation),
media techniques, figurative language, and genre to create, critique, and discuss print and
non-print texts.
■ Adjust their use of spoken, written, and visual language (e.g., conventions, style, vocabulary)
to communicate effectively with a variety of audiences and for different purposes.
■ Employ a wide range of strategies as they write and use different writing process elements
appropriately to communicate with different audiences for a variety of purposes.
■ Use a variety of technological and information resources (e.g., libraries, databases, computer
networks, video) to gather and synthesize information and to create and communicate knowledge.
■ Conduct research on issues and interests by generating ideas and questions, and by posing
problems. They gather, evaluate, and synthesize data from a variety of sources (e.g., print and
non-print texts, artifacts, people) to communicate their discoveries.
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Standards for the English Language Arts, by the International Reading Association and the National Council of
Teachers of English, Copyright 1996 by the International Reading Association and the National Council of Teachers
of English. Reprinted with permission.
Technology Standards
The activities in this Teacher’s Guide were created in compliance with the following National
Education Technology Standards from the National Education Technology Standards Project.
■ Proficient in the use of technology.
■ Demonstrate a sound understanding of the nature and operation of technology systems.
■ Use a variety of media and formats to communicate information and ideas effectively to multiple audiences.
■ Use technology tools to enhance learning, increase productivity, and promote creativity.
■ Use technology tools to process data and report results.
■ Use technology to locate, evaluate, and collect information from a variety of sources.
The National Education Technology Standards reprinted with permission from the International Society of Technology
Education.
PROGRAM OVERVIEW
This program introduces the cell as the basic unit of life, which when working in groups form tissues, organs, systems and organisms. The similarities between cells and cities are used as a basis
for understanding how these complex structures grow, reproduce, function, and die.
MAIN TOPIC AREAS
Topic 1: What Are Cells?
The program begins by explaining what a cell—the basic building block of all life—is. Each cell is
made up of many different structures, and many different activities occur within the cell system.
This sets the foundation for the program’s analogy of the cell and a city.
Topic 2: Microscopes
The introductory segment includes an explanation and demonstration of the power of different
types of microscopes. This segment also gives the student an idea of the various sizes and shapes
of different cells.
Topic 3: Cells and Cities
The slide show portion of the CD-ROM describes the organization of the cell and relates the various organelles to buildings and structures found in a city. Just as the city hall, factories, highways, and recycling plants serve important roles in a city, the cell organelles perform similar life
functions inside the cell.
Topic 4: Cell Organelles
In this section, the student has the chance to “start the microscope” and take a closer look at
the functions and intricacies of some common cell organelles, including mitochondria, the nucleus, cell membrane, and ribosomes. Cell reproduction and death is also examined in this section.
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FAST FACTS
■ An average plant cell is about three times larger than an animal cell.
■ The average life span for a stomach cell is two days; a brain cell can live for a lifetime.
■ Similar to the way the English language uses twenty-six letters to form thousands of words;
DNA strands use four different nucleotides, or ”letters,” to form “words,” or chains of information.
■ Researchers are attempting to prevent animal extinctions by collecting and freezing genetic
material from endangered animal species.
■ Human Genome Project researchers have discovered that all humans are 99.8 percent genetically identical.
■ The adult human body contains 5 to 6 quarts of blood, while an infant has about 1 quart of
blood.
■ Chromosomes carried by the male sperm determine whether an embryo will develop into a
male or female organism.
■ The unfertilized ostrich egg is the world’s largest cell.
■ The human brain is made up of about one trillion nerve cells.
■ An average person sheds 40 pounds of skin cells over a lifetime.
■ Direct sunlight causes the lysosomes in skin cells to burst. The enzymes released kill the cells of
the epidermis and lead to the blistering and peeling experienced with sunburn.
■ Lysosomes are responsible for the loss of a tadpole’s tail during metamorphosis. They digest
the tail and make the materials used to construct parts of the new frog.
■ There are over two hundred different types of cells in the human body.
■ It is the linking of sulphur atoms in protein molecules that causes some people’s hair to be
curly.
■ Over 10 billion molecules can be found inside a single cell.
VOCABULARY TERMS
archaea: Bacteria-like microorganisms that live at high temperatures or produce methane.
bacteria: The smallest of microscopic organisms. Abundant in nature, they multiply rapidly.
Certain species are active agents in fermentation, while others appear to be the cause of certain
infectious diseases.
cell: The fundamental unit that makes up all organisms on Earth.
cell membrane: Also called the plasma membrane. The cell membrane regulates the flow of
materials into and out of the cell.
chloroplasts: Perform photosynthesis by taking in sunlight, water, and carbon dioxide to make
oxygen and sugar (a form of food). Also contain a green pigment called chlorophyll, which gives
plants a green color.
chromosomes: Long, thread-like bodies composed of DNA and protein, found in the nucleus of
eukaryotic cells. They contain the genes that contain the code for all the organism’s proteins.
cytoskeleton: The transparent network of protein filaments that maintains the cell’s shape,
holds organelles in place, and moves parts of the cell around if needed.
DNA (Deoxyribonucleic acid): The chemical that makes up all genes, and therefore chromosomes.
endoplasmic reticulum (ER): A folded membrane that moves materials around in the cell.
eukaryotic cell: A cell with a nucleus and other organelles with membranes around them.
Animal, plant, fungi and protista cells are eukaryotic.
golgi body (golgi apparatus): Package and move proteins to the outside of the cell.
lysosome: Contains enzymes that digest waste and worn out cell parts.
microbe: A minute, single-cell life form; a microorganism.
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microorganism: An organism of microscopic or submicroscopic size.
mitochondria: Organelles where food molecules are broken down and energy is released.
nucleus: Control center of the cell where DNA is stored.
organelle: One of the structures found in the cell, which perform a function of the cell.
photosynthesis: The process in green plants and certain other organisms by which carbohydrates are synthesized from carbon dioxide and water using light as an energy source. Most
forms of photosynthesis release oxygen as a byproduct.
plant: An organism that uses photosynthesis to produce its own food. Its cells contain cellulose
and a cell wall.
prokaryotic cell: A cell that does not have a nucleus and other organelles with membranes
around them. Bacteria are examples of prokaryotic cells.
RNA (Ribonucleic acid): The chemical that “copies” the information from the DNA and carries
it to the ribosomes to be translated into protein.
ribosome: The site of protein synthesis, where the RNA is translated into protein.
vacuole: Vacuoles store water, food, pigments, waste, or other materials. Vacuoles are large in
plant cells and small in animal cells.
virus: Not classified by a kingdom, a virus cannot “live” on its own, but uses another cell’s
machinery to reproduce.
PRE-PROGRAM DISCUSSION QUESTIONS
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7.
How big is a cell?
Are all cells the same size and shape?
In what ways do you think cells are like cities?
What important functions occur within a cell?
Can you think of any systems in the body or in a city that perform similar functions?
Name as many parts of the cell as you can and tell what they do for the cell.
Why is it valuable to study the structure, functions and relationships of cells?
POST-PROGRAM DISCUSSION QUESTIONS
1. Cell organelles perform many different functions. What happens if an organelle does not
function correctly? Consider organelles such as mitochondria, chloroplasts, and ribosomes.
2. How do cells react to a lack of water or oxygen? Do all cells need water and oxygen?
3. How is a virus different from a cell?
4. Ribosomes produce many different types of protein molecules. Why are protein molecules
important, and what do they do?
5. If mitosis produces two identical daughter cells with the same genetic information, how can
the human body grow from one fertilized egg into an organism with over 200 different types
of cells?
6. The CD-ROM focuses on the structure of eukaryotic cells. What types of cells are prokaryotic
cells? How do they survive without a nucleus?
GROUP ACTIVITIES
What’s in the Water?
Work in small groups to collect samples from ponds, streams, and other water sources in your
area. Examine each water sample under a microscope (use more than one type of microscope if
available). Sketch examples of any organisms that are visible. In what ways are they the same?
How do they differ? Are any organelles visible?
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Building a Cell
Use common household items such as string, jellybeans, buttons, plastic wrap, baggies, coins,
tape, and glue to construct a model cell city. Indicate the type of cell that it is, label the
organelles, and describe the cell’s functions.
The Human Genome Project
Learn about the current findings of the Human Genome Project. What information has been
established? How can this information benefit modern medicine? Develop a futuristic, hypothetical therapy or treatment based on the discovery and mapping of a specific gene.
INDIVIDUAL STUDENT PROJECTS
Genetic Mutation
Explore the concept of genetic mutation and how it relates to diseases such as cancer and Down
Syndrome, the theory of evolution, and gene therapy. Choose a subject that is of interest to you
and present your findings to the class in an oral presentation. Create a poster, fact sheet, or
other visual material to support your presentation.
From Acids to Proteins
Use the Internet or library to get a list of the twenty essential amino acids that the human body
needs to create proteins. Then, visit a local pharmacy or health food store to see how many different types of amino acids are available. What do the labels claim these supplements do?
Return to the library or Internet to see if you can find any research or studies that have been
done on the effectiveness of these supplements.
Solar Energy
Chloroplasts in plant cells conduct photosynthesis using energy from the sun to create food for
the plant. Animal cells break down food molecules during cellular respiration to obtain energy.
Draw a diagram that shows the molecular breakdown of photosynthesis and cellular respiration.
How do these processes work together to maintain balance in an ecosystem? Do plant cells conduct cellular respiration?
Truth and Dare
Scientists say that yeast cells need sugar (food/energy), water, and warmth to reproduce. How
true is this statement? Plan an experiment to see if the scientists are entirely correct.
INTERNET ACTIVITIES
Earth’s Family Tree
All living creatures inherit traits from their ancestors. What traits have you inherited from you
parents: from your grandparents? Do you share any similar traits with your brothers, sisters, or
cousins?
Use the Internet to learn about Mendelian genetics. Then, create a poster to illustrate how physical characteristics have been passed from one generation to another in your family. Highlight the
principles of heredity by charting the physical traits of your parents, grandparents, and other relatives. Which traits are dominant? Which are recessive? Which characteristics appear to be inherited vs. acquired?
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Genetic Engineering
Investigate current events in genetic engineering. Use the Internet to find out about current
research, political actions, and sociological perspectives. Choose one aspect that is of particular
interest to you and share it with the class through an oral presentation.
Cell Malfunctions
Search the Internet for examples of how external factors (such as the environment, drugs, etc.)
can affect the functioning of cells, either positively or negatively. Identify at least three factors,
and explain how each impacts the cell.
Evolution Now
According to Charles Darwin’s Theory of Evolution, the vast and diverse number of living species
on earth today can be attributed to mutation, adaptation, and survival of the fittest. What evidence can we see in the natural world that might support this theory? Write a short report that
summarizes Darwin’s Theory.
ASSESSMENT QUESTIONS
Q: The mitochondrion is the power station of the cell. (True or False)
A: True
Feedback: Mitochondria release energy in the form of ATP molecules.
Q: Most cells are microscopic. They are measured in units called _____________ .
(a) microbes
(b) millimeters
(c) pixels
(d) microns
A: (d)
Feedback: They are measured in units called microns, or micrometers.
Q: Living organisms can be made up of just one single cell or many different types of cells. (True
or False)
A: True
Feedback: Some organisms are single-celled, while others are more complex, consisting of many
different types of cells.
Q: In workshops and factories, goods and products are made from raw materials. This work is
often done on a production line, following a clear set of instructions. These production lines
function in a way which is similar to a _____________________ .
(a) ribosome
(b) lysosome
(c) nucleus
(d) RNA
A: (a)
Feedback: Ribosomes produce proteins in accordance with instructions from the RNA.
Q: Name four cell organelles and their functions.
A: May include the cell wall, cell membrane, cytoskeleton, ER, vacuole, chloroplasts, nucleus,
golgi apparatus, mitochondria, etc.
Feedback: The organelles inside the cell perform many important functions which sustain the
cell.
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Q: All living cells have some basic features in common. Which of the following is not a feature
common to all cells?
(a) They all have some structure that separates the inside of the cell from the outside.
(b) They all contain, at least at some stage of their life, some genetic material.
(c) They all produce proteins.
(d) They all contain a nucleus.
A: (d)
Feedback: Prokaryotic cells do not contain a nucleus.
Q: DNA is made up of chromosomes. (True or False)
A: False
Feedback: The chromosomes are made up of coils of DNA, which carry all the organism’s genetic information.
Q: The _______________ is the transportation system of the cell.
(a) mitochondria
(b) cytoskeleton
(c) endoplasmic reticulum (ER)
(d) cell membrane
A: (c)
Feedback: The ER transports molecules around the cell.
Q: Many types of cell die and reproduce often during the life of an organism. Which of the following types of cell do not?
(a) Skin cells
(b) Red blood
(c) Brain
(d) Cheek
A: (c)
Feedback: There are a limited number of brain cells in the body, and the same cells are used
over a lifetime.
Q: Mitosis begins in the nucleus with the replication of the __________ .
(a) mitochondria
(b) chromosomes
(c) cytoplasm
(d) RNA molecules
A: (c)
Feedback: In the first stage of mitosis, the chromosomes replicate and form two identical sets of
DNA.
ADDITIONAL RESOURCES
WEBSITES
Communication Technology Lab of Michigan State University “Microbe Zoo”
www.commtechlab.msu.edu
The Franklin Institute Online: Living Things
www.fi.edu/tfi/units/life
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Basic Principles of Genetics: An Introduction to Mendelian Genetics
http://anthro.palomar.edu/mendel/default.htm
Human Genome Project Information
www.ornl.gov/TechResources/Human_Genome/home.html
Life Science Connections—Life Science Safari
http://vilenski.org/science/safari
Cells alive!
http://www.cellsalive.com/index.htm
BOOKS
The Cartoon Guide to Genetics by Larry Gonick, Mark Wheelis (Contributor). Harper Perennial,
1991. ISBN: 0062730991
Exploring The Way Life Works: The Science of Biology by Mahlon B. Hoagland, Bert Dodson,
Judith Hauck. Jones & Bartlett Pub., 2001. ISBN: 076371688X
The Origin of Species by Charles Darwin. Grammercy, 1998. ISBN: 0517123207
Other End of the Microscope: The Bacteria Tell Their Own Story, a Fantasy by Bert Dodson
(Illustrator), Eleanor S. Tupper (Editor), Elmer W. Koneman. American Society for Microbiology,
2002. ISBN: 1555812279
The Way Life Works by Mahlon Hoagland and Bert Dodson. Times Books, 1995.
ISBN:0812920201
OTHER PRODUCTS
Playing God: Human Cloning, VHS, Cambridge Educational
This program presents an in-depth exploration of the ethical concerns regarding human cloning.
A variety of perspectives are canvassed from the theological, legal, and scientific fields, including
interviews with Dr. Ian Wilmut, the first scientist to successfully clone a mammal—Dolly, a sheep.
Order no: 29332, www.cambridgeeducational.com, 1-800-468-4227
Cellular Respiration, VHS, Cambridge Educational
This six-part series begins by examining the essential fuels and machinery used by living forms to
sustain themselves. The fuel glucose is then broken down through the processes of glycolysis,
the Krebs cycle, and oxidative phosphorylation. Finally, the connections between the processes of
cellular respiration and nutrition are examined. The series includes The Cell and Energy,
Glycolysis 1, Glycolysis 2, The Krebs Cycle, Oxidative Phosphorylation, Metabolism, and
Nutrition (10 minutes each).
Order no: 3668, www.cambridgeeducational.com, 1-800-468-4227
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Sequencing Life, VHS, Cambridge Educational
In this program, Doctors Francis Collins, head of the Human Genome Project, and J. Craig
Venter, CEO of Celera Genomics, discuss the completion of the mapping of the human genome
and what that achievement means for the future of medicine. Initial discoveries indicate that the
structure of human DNA is simpler but its functions far more complex than previously imagined.
Order no: 29088, www.cambridgeeducational.com, 1-800-468-4227
For information on other programs
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