CAMBRIDGE CORE SCIENCE SERIES: BIOBASICS

MICROORGANISMS

Teacher’s Guide

INTRODUCTIONThis Teacher’s Guide provides information to help you get the most out of the BioBasics:Microorganisms video program. This program is the seventh of the eight-part BioBasics life |sci-ences series. The information in this guide will allow you to prepare your students before usingthe program, and to present follow-up activities to reinforce the program’s key learning points.

The BioBasics series is intended to excite young people about science and teach them conceptsthat meet national educational standards for science literacy. Science, in its multiple disciplines, isinherently fascinating and helps explain the world in and around us. In addition to fulfilling ournatural curiosity, there are numerous practical benefits to studying science: it teaches critical think-ing skills that help us make informed and reasoned decisions, solve problems, think creatively, andcontinue learning.

LEARNING OBJECTIVESAfter viewing Microorganisms, students will be able to:

� Define microorganisms and describe their basic characteristics.� Name the three domains of life.� List the six kingdoms of life. � Describe several ways that microorganisms are central to life.� Identify and describe each general type of microorganism according to its characteristics and

functions.� Describe the hazards and benefits to humans of microorganisms.

EDUCATIONAL STANDARDSThe content of this program has been aligned with the following national and state educationalstandards and benchmarks.

NATIONAL STANDARDS Science The activities in this Teacher’s Guide were created in compliance with the following NationalScience Education Standards from the Association for the Advancement of Science.

� As a result of activities in grades 9-12, all students should develop abilities necessary to do sci-entific inquiry, and understandings about scientific inquiry.

� As a result of their activities in grades 9-12, all students should develop an understanding ofthe cell, molecular basis of heredity, biological evolution, interdependence of organisms, mat-ter, energy, and organization in living systems, and behavior of organisms.

Reprinted with permission from National Science Education Standards © 1999 by the National Academy of Sciences, courtesy of

the National Academies Press, Washington, D.C.

2 Copyright © 2005 Cambridge Educational®

English Language Arts StandardsThe activities in this Teacher’s Guide were created in compliance with the following NationalStandards for the English Language Arts from the National Council of Teachers of English.

� Students 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.

� Students employ a wide range of strategies as they write and use different writing processelements appropriately to communicate with different audiences for a variety of purposes.

� Students apply knowledge of language structure, language conventions (e.g., spelling andpunctuation), media techniques, figurative language, and genre to create, critique, and dis-cuss print and non-print texts.

� Students conduct research on issues and interests by generating ideas and questions, and byposing 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 in ways that suittheir purpose and audience.

� Students use a variety of technological and information resources (e.g., libraries, databases,computer networks, video) to gather and synthesize information and to create and communi-cate knowledge.

� Students use spoken, written, and visual language to accomplish their own purposes (e.g., forlearning,

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 StandardsThe activities in this Teacher’s Guide were created in compliance with the following NationalEducation Technology Standards from the National Education Technology Standards Project.

� Students use technology tools to enhance learning, increase productivity, and promote creativity.� Students use technology to locate, evaluate, and collect information from a variety of sources. � Students evaluate and select new information resources and technological innovations based on

the appropriateness for specific tasks.

The National Education Technology Standards reprinted with permission from the International Society for Technology Education.

PROGRAM OVERVIEW Microorganisms introduces the three domains of life and the six kingdoms of microorganisms.

MAIN TOPICSTopic 1: Introduction to Microorganisms.Microorganisms are organisms of microscopic and even sub-microscopic size. They are usually,but not always, single-celled. Microorganisms are at the root of the evolutionary tree and arecentral to life on our planet. They are the oldest life form—fossils of microorganisms that areover 3.5 billion years old have been found. They are found everywhere in nature: in the soil, inthe air, in water, on every surface, and even inside and on the human body. Microorganismsmaintain our atmosphere, aid in decomposition, assist in digestion, fight disease, and are used infermentation. Microbes are found at every level of the taxonomy. 3

Topic 2: Types of MicroorganismsArchaea are usually single-celled. They are bacteria look-alikes, but are biochemically distinctfrom them. True bacteria, along with archaea, are the oldest life forms on Earth. They are themost abundant organisms. Fungi are single and multicellular eukaryotes. Protista are mostly sin-gle-celled, with some simple multi-cellular eukaryotes. This includes protozoa, algae, slime moldsand water molds. Viruses are tiny, infectious particles that are made up of genetic material (RNAor DNA) surrounded by a protein coat called a capsid. Symbionts are two or more microorgan-isms that have evolved to work together to their mutual benefit.

FAST FACTS� No-one knows how many microorganisms exist, but it is likely that we are aware of only a

small percentage of them.� Microorganisms are key to understanding the past, present, and future of our planet.� Cell behavior can be affected by molecules from other parts of the organism or even other

organisms.� Algae produce most of the oxygen we breathe. They obtain energy through photosynthesis.� Most cells function best within a narrow range of temperature and acidity. At very low tem-

peratures, reaction rates are too slow. High temperatures and/or extremes of acidity can irre-versibly change the structure of most protein molecules. Even small changes in acidity canalter the molecules and how they interact.

� No one is certain who invented the first microscope, but credit for the first compound micro-scope is usually given to Zacharias Jansen of Holland, who built it around the year 1595.

� In 1665, Robert Hooke discovered cells when he examined a piece of cork under a microscopeand saw that it was made up of small, empty compartments.

� Rhizobia lives on the roots of legumes. They supply the plants with nitrogen, and the plantssupply the rhizobia with carbohydrates.

� Lichens are algae and fungi living together in a symbiotic relationship. Together they can sur-vive in otherwise inhospitable environments, such as on rocks and in deserts.

� One famous water mold is the potato blight, which was responsible for the start of the 1847Irish Potato Famine.

� Prions are infectious proteins which don’t need DNA or RNA to transfer information. Prionsare linked to degenerative neurological diseases. They were discovered by Stanley Prusiner,who found evidence that they caused scrapie in sheep. His work won him the Nobel Prize forMedicine in 1997.

VOCABULARY TERMSaerial: Pertaining to the air. amoebae: Any of a polyphyletic grouping of organisms that move and feed using pseudopodia. amphitrophic: Organisms capable of gaining energy and nutrients by both autotrophic and heterotrophic means. aquatic: Pertaining to water, as in aquatic habitat (ponds, lakes, streams, oceans, etc). archezoa: Eukaryotes believed to have evolved before the origin of mitochondria. autotrophic: Organisms which trap energy from physical or chemical sources and use the ener-gy to assemble the macromolecules of which they are made. axoneme: A geometrically packed group of microtubules used to support flagella.bacterivore: An organism that eats bacteria. character: Any trait of an organism that can be used for recognizing, differentiating, or classify-ing a taxon.

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chlorophyll: A family of pigments used in photosynthesis to trap radiant energy. chloroplast: An organelle found in eukaryotic algae and plants. The site of photosynthesis andof chlorophyll. chromist: A term used variously to refer to algae with chloroplasts having chlorophylls a and c. chromosome: A long strand of eukaryotic DNA. cilium: A hair-like projection from the surface of a cell. Cilia move together to propel the cell, orto move the medium surrounding the cell. classification: The practice of arranging organisms in named groups (taxa). coccoid: Round in shape. commensal: An organism that derives nourishment or shelter by living in close association withanother organism (the host), without damaging the host. convergent evolution: Evolution of similarities in unrelated groups of organisms.cytopharynx: Mouth-like structure of some cells. cytoplasm: The matter which makes up cells, within which organelles occur. cytoproct: The site at which old food vacuoles fuse with the cell surface, and undigestedresidues are excreted. cytoskeleton: Intracellular components used to provide shape to a cell or to create tracts alongwhich cellular organelles may be moved, mostly comprised of microtubules and actin filaments. cytostome: Literally, “the cell mouth.” This term is used in reference to organisms that ingestfood at one or more locations. It is also used in reference to the region(s) of the cell surfacethrough which food gains entry into the cell. daughter cells: The products of cell division of protists. detritus: Fragments of dead plant and animal material before, during, and after breakdown byagents of decay. diffusion feeding: Feeding strategy in which the predator relies on the movements of the preyto make contact. enzyme: A protein that acts as a catalyst, accelerating the rate of specific biochemical reactions. flagellate: An organism (usually a protozoan) that has whip-like appendages.heterotrophic: A mode of nutrition in which the consumer relies upon molecules created byother organisms for energy and nutrients. host: An organism that provides nourishment and/or shelter to a commensal or a parasite. marine: Pertaining to the sea. membranelle: A compound structure comprised of many cilia and associated with the mouth ofa ciliate. microorganism: Usually single-celled creature that is too small to be seen without a microscope.The term may be applied to bacteria, archaea, and viruses, as well as certain fungi and protists. microtubule: A sub-cellular structure comprised of the protein tubulin and used for support,Part of the cytoskeleton. mixotrophic: Used in reference to organisms that use a mixture of nutritional strategies, such asorganisms with chloroplasts. motile: Moving, for example by swimming, gliding, crawling, jumping, or kicking. Part of thebody (e.g., cilia) may be motile in a cell which is not motile and is fixed in one position. multicellular: An organism consisting of more than one cell. nucleus: An organelle found only in eukaryotic cells, in which most of the cellular DNA (geneticmaterial) is located. Most cells have a single nucleus, but certain species may have many nuclei. ontogeny: The developmental history of an individual organism from its origin to its death. organelle: A structure within a cell that performs a specific function.organism: Any living creature. A plant, animal, or micro-organism. osmotrophic: A form of nutrition in which soluble compounds are taken up by the organism.parasitic: An interaction between organisms in which one (the parasite) lives in or on the livingtissue of another (the host), deriving nutrients at the expense of the host. Parasites usually live5

for some time in association with their hosts rather than killing them soon after encounter. phagocytosis: The ingestion of visible particles of food by enclosing them with a membrane toform a food vacuole. photosynthesis: A means of acquiring energy for metabolism which involves trapping radiantenergy in chloroplasts, the use of that energy to break up water molecules (hydrolysis) and toconvert released energy into an accessible form. phylogeny: The evolutionary history of a group of organisms.plankton: Organisms living in the water column (above the sediment). predation: An interaction between organisms in which one (the predator) kills and eats theother (the prey). prokaryote: Unicellular organisms lacking a membrane-bound, structurally discrete nucleus andmembrane-bound organelles. The term is generally applied to bacteria and archaea. protein: A large molecule composed of amino acid chains. Proteins perform a wide variety ofcellular functions. Examples are hormones, enzymes, and antibodies. protist: A group consisting mostly of one-celled eukaryotes that are not animals, true fungi, orgreen plants. Includes protozoans, slime molds, and certain algae.protozoan: Any of a large group of single-celled, usually microscopic, eukaryotic organisms,such as amoebas, ciliates, flagellates, and sporozoans.spore: Unicellular body produced by plants, fungi, and some microorganisms. Spores can giverise to a new individual either directly or after fusion with another spore. terrestrial: Pertaining to land. unicellular: Consisting of a single cell. vacuole: A structure in a cell enclosed by a membrane. Usually food vacuoles (associated withthe digestion of food) or contractile vacuoles (association with the excretion of fluid). Small vac-uoles may be called vesicles.

PRE-PROGRAM DISCUSSION QUESTIONS1. Can you think of a few questions early microbiologists might have tried to answer? 2. Microbes are everywhere! How safe do you think your water is? Why? Where might infectious

microbes come from? How is water treated now and what’s being done to make it even safer?3. As effective as antibiotics have been, decades of drug exposure has led to microbes that are

fighting back. Antibiotic resistance is increasing worldwide, creating organisms that no longerrespond to treatment with many of the drugs that we have. What do you think scientists,doctors, and the government are trying to do? What do you think you can do?

4. What schools of scientific thought (such as chemistry, botany, psychology, etc) do you thinkbenefit from advances in microbiology?

5. What do you think are some of the links between microbiology and space science?

POST-PROGRAM DISCUSSION QUESTIONS1. What elements are included in the essential nutrients for most bacteria? 2. What does the term “growth factor” mean? What are some examples? What are some

organisms that require them?3. How do heterotrophs and autotrophs differ from each other?4. How does your understanding of prokaryotic and eukaryotic cell development impact your

understanding of evolution?5. In complex organisms, cells perform a variety of functions. How is cellular cooperation and

collaboration similar to interpersonal teamwork?

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GROUP ACTIVITIESBreaking Down the Mold Divide students into groups of four and ask them to design an experiment to test a hypothesis orquestion about mold. Questions might include the following:

• How can you learn more about the requirements of fungi? • What procedures would you use? • What would you measure? • What kinds of food or other substances would you use to test your hypothesis? • What kinds of liquids might you use? What amounts? • What if you altered the temperature? • What if you left them exposed to light? • How might preservatives in the substance affect the test?

A Virus! A Virus!Divide students into groups and have each group give a presentation on a specific type of virus.Students should discuss how viruses are grown and the types of organisms that can be infectedwith viruses. As visual aids, diagrams of the virus should include capsid, capsomere, glycoproteinspikes, and nucleic acid (with the types of nucleic acid that can be found in viruses).

Microorganism CrosswordUsing the vocabulary list from Microorganisms, have each student group develop a crosswordpuzzle or wordfind and an answer key. Groups should then exchange projects and solve.

INDIVIDUAL STUDENT PROJECTSHistory of MicroorganismsWrite an essay discussing the history of the discovery of microorganisms. Include in your essayinformation about the scientists whose work contributed to what we know today (including thefoundations of cell theory), as well as some historical background about the time period duringwhich each scientist lived and worked.

Are Microorganisms Alive?In this activity, students list the factors required for basic life processes and compare this list towhat microorganisms are capable of doing. How do these microorganisms’ processes differ fromhumans’ processes? Students should present their answers in 3-5 written paragraphs.

Build a MicroorganismIn this project, students draw or build a model of a prokaryotic cell and a eukaryotic cell. Theyshould label its parts, identify its functions, and highlight the differences between them.

INTERNET ACTIVITIESMicrobiology in the News In this activity, students use an Internet search engine to research current headlines in microbiolo-gy and their relevance to our everyday lives. The news stories may deal with threats to humanhealth such as HIV or the latest flu epidemic, or with the use of microbiology to boost agriculturaloutput. Pick one story and present it to the class.

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Bugs and SuperBugsIn this activity, students use the Internet to research the use, effectiveness, and pitfalls of anti-bacterial products. There are now more than 700 of these items on the market, including anti-bacterial sponges, toys, hand soaps and lotions, and window cleaners. How many of these prod-ucts do students have at home? Why is the Centers for Disease Control and Prevention so con-cerned about their use?

Microorganisms in MotionMicroorganisms employ a variety of locomotion mechanisms to maneuver through spaces. Havestudents use the Internet to view examples of these motions, Students should describe their find-ings to the class.

ASSESSMENT QUESTIONSQ: What are the only organisms made up of prokaryotic cells?A: Bacteria and blue-green algaeFeedback: Prokaryotic cells are simpler and smaller than eukaryotic cells, do not have a nucleusor other membrane-bounded internal structures that are typical of most cells, and have toughcell walls that make them resistant to environmental changes.

Q: Microorganisms are always single-celled. (True or False)A: FalseFeedback: Microorganisms are usually, but not always, single-celled, and are organisms of micro-scopic and even sub-microscopic size.

Q: Microorganisms are the oldest form of life. (True or False)A: TrueFeedback: They are the oldest life form. Fossils of microorganisms that are over 3.5 billion yearsold have been found.

Q: What kind of microorganism might be used to deliver gene therapy?a) Bacteriab) Algaec) Virusesd) Fungi

A: c) VirusesFeedback: Viruses can invade organisms and cause diseases, and might some day be engineeredto deliver cures as well.

Q: Tetanus, typhoid, pneumonia, cholera, tuberculosis, and food-borne illnesses are caused bywhat type of microorganism?A: BacteriaFeedback: Antibiotics are the drugs used to combat bacteria—they either kill them or inhibittheir growth.

Q: What are some positive uses for bacteria?A: Bacteria make vitamins, decompose garbage, and maintain our atmosphere, and can be bio-engineered to produce medicines such as insulin, or to help detect and clean up toxic wastes.Feedback: While some bacteria are harmful to humans, it’s clear that others improve our qualityof life dramatically.

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Q: Protozoa, algae, slime molds, and water molds fall into what kingdom of microorganisms?A: ProtistaFeedback: Protists are mostly single-celled, some simple multi-cellular (red and brown algae),eukaryotes, and are ubiquitous in water and soil. Some are parasites.

Q: Ebola, HIV, smallpox, rubella and influenza are human diseases caused by ________.A: virusesFeedback: Viruses are tiny, infectious particles that are made up of genetic material (RNA orDNA) surrounded by a protein coat called a capsid. Viruses are parasites—they lack the cellularmachinery to reproduce on their own, but use cells of living hosts to reproduce, usually causingdisease in the process.

Q: Over 95% of microbes are good for you. (True or False)A: TrueFeedback: Microbes live in the water we drink, the food we eat, and the air we breathe—andmost either don’t bother humans or aid in our life processes.

Q: What does lactobacillus acidophilus do to milk?A: Lactobacillus acidophilus helps turn milk into yogurt.Feedback: Lactobacillus acidophilus is one of the bacteria that aid in this process.

ADDITIONAL RESOURCESWEB SITES

The National Academy of Scienceswww4.nationalacademies.org

National Library of Medicinewwwihm.nlm.nih.gov

American Society for Microbiologywww.microbeworld.org

Centers for Disease Control and Preventionwww.cdc.gov

BOOKS

Biology: Science for LifeBy Colleen M. Belk and Virginia M. Borden Prentice Hall, 1st edition; July 7, 2003; Paperback, 477 pagesISBN: 0130892416

Biology: Concepts and Connections (4th Edition)By Neil A. Campbell, Jane B. Reece, Lawrence G. Mitchell, and Martha R. TaylorBenjamin Cummings; June 22, 2002; Hardcover, 781 pagesISBN: 080536627X

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Biology for DummiesBy Donna Rae SiegfriedFor Dummies; September 15, 2001; Paperback, 384 pagesISBN: 0764553267

OTHER PRODUCTSThe Nature of Biology, VHS/DVD, Cambridge EducationalWhy study biology? What’s it all about? Why does it matter? This is the video that helps answerthese common questions about biology. Images from the natural world reinforce the sense ofwonder and excitement involved in studying life science. Interviews with science professionals helpviewers appreciate the impact of biology on society. The program is organized around the follow-ing themes: Diversity of Life, Heredity, Cells, Interdependence of Life, Flow of Matter and Energy,and Evolution of Life. A Cambridge Educational Production. One 30-min video and guide. Order #: 8181, www.cambridgeeducational.com, 1-800-468-4227

Themes of Biology, Posters, Cambridge EducationalThis collection of seven posters combines striking photography, colorful illustrations, and suc-cinct, informative text to represent these major themes of biology. Attractive resources for anyscience classroom, these educational posters help students make connections between key lifescience concepts and things they experience every day in the living environment. Posters include:

• Diversity of Life • Classification• Evolution • Heredity• Flow of Matter and Energy • Interdependence of Life• Cells

Order #: 27164, www.cambridgeeducational.com, 1-800-468-4227

Evolution Video Library, DVD, Films for the Humanities & SciencesPart of the Life Science series, this program contains 17 video clips on evolution and naturalselection, diversity of life, and genetics. Correlates to National Science Education Standards. AUser’s Guide is included, containing an overview; a numbered index of clips, with brief descrip-tions and lengths; suggested instructional strategies; and a list of additional resources. ADiscovery Channel/FFH&S Production. Clips include:

Order #: 30954, www.films.com, 1-800-257-512610

• Introduction to Evolution• Elephant Evolution• Charles Darwin• Adaptation• Insect Evolution• Survival• Birds of Prey• Reptile Characteristics• Mammal Diversity and Survival

• Animals and Extremes• Plant Diversity• Introduction to Genetics• Cloning• Novelty Gene• Crime Solvers• Transgenics• Biotechnology

Understanding Bacteria, VHS/DVD, Films for the Humanities & SciencesHow do benign bacteria work? How are infectious bacteria fought? And how are scientistsadapting both types of bacteria to good—or evil—uses? This program answers those questionsthrough the observations and insights of Stanley Falkow, president of the American Society forMicrobiology; Fred Tenover, chief of antibiotic resistance investigations at the Centers for DiseaseControl and Prevention; and other specialists. The role of E. coli in digestion, the relationshipbetween H. pylori and ulcers, medical applications of C. botulinum, the use of bacteria to cleanup toxic waste, the exploitation of anthrax as a weapon, and the discovery of extraterrestrial bac-teria are all considered. A Discovery Channel production. (52 minutes)Order #: 11931, www.films.com, 1-800-257-5126

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