TEACHER’S G UIDE
Follow-up Activities
• I m agine a colony of 10 bacteria that doubles eve ry 20 minu t e s . H ave
students calculate how many bacteria will be in the colony after two
hours. Based on this information, h ave each student guess how long it
would take for the colony to surpass one million org a n i s m s .Then ask the
students to do the computation and compare their guesses with the
calculated time.
• H ave students conduct a poll to determine if people consider bacteri a
helpful or harmful. Tally the results and make graphs for the subgroups
polled such as: elementary students, teens, high school students,
parents and grandparents.
• Have students observe the effect of tempera t u re on a glass of milk at
room tempera t u re over the course of a few days and compare it to a
glass of milk that has been re f ri ge ra t e d . Students can then design an
experiment that proves that refrigeration is useful in retarding bacteria
growth.
• Explain to students that people have not always known that bacterial
i n fections can be prevented by hand-washing. R e fer students to the Web
page www.accessexcellence.org/AE/AEC/CC/hand_background.html
for info rmation about the history of hy giene in public health and for lab
activities designed to illustrate the fact that bacteria are present virt u a l ly
eve rywhere.
TEACHER’S GUI DE
Suggested Print Resources
• Gottfried,Ted. Alexander Fleming: Discoverer of Penicillin. Franklin
Watts, Danbury, CT; 1997.
• Holley, Dennis. Viruses and Bacteria: Hands-On Minds-On
Investigations for Middle to High School Students. Critical Thinking
Books and Software, Pacific Grove, CA; 1999.
• Levine, Shar. Fun With Your Microscope. Sterling Publishers, New York,
NY; 1999.
• Lovett, Sarah. Micro Monsters. Davidson Title, Jackson,TN; 1996.
Bacteria
Grades 5–8
S
Suggested Internet Resources
Periodically, Internet Resources are updated on our web site at
www.LibraryVideo.com
• www.amnh.org/explore/infection/index.html
“Infection Detection Protection” is a Web site hosted by the American
Museum of Natural History that contains a great deal of information
about microbes and their effect on our lives. Several interactive games
that teach about bacteria are also included.
• www.microbe.org/microbes/bacterium1.asp
The American Society for Microbiology hosts “Stalking the Mysterious
Microbe,” a site for elementary students interested in learning more
about microorganisms including bacteria.
• commtechlab.msu.edu/sites/dlc-me/zoo/
The “Microbe Zoo” is an excellent interactive site for middle-schoolers,
developed with the input of scientists from Michigan State University.
Teacher resources and activities about bacteria are included.
• www.fightbac.org/educators/gameplan.htm
Hands-on activities for middle school students concerning the fight
against bacteria are available on this site and are sponsored by the
Partnership for Food Safety Education.
TEACHER’S GUIDE CONSULTANT
Paula J. Bense, M.Ed.
Curriculum Specialist, Schlessinger Media
Conrad M. Follmer
25 years as a K–5 Science & Math Coordinator for a Pennsylvania public
school system, currently an independent consultant to elementary schools.
TITLES
• BACTERIA
• FUNGI
Teacher’s Guides Included
and Available Online at:
7/05
5
TEACHER’S G UIDE
• PROTISTS
• VIRUSES
800-843-3620
Teacher’s Guide and Program Copyright 2000 by Schlessinger Media,
a division of Library Video Company
P.O. Box 580, Wynnewood, PA 19096 • 800-843-3620
Executive Producers: Andrew Schlessinger & Tracy Mitchell
Programs produced and directed by Stone House Productions, LLC
All rights reserved
N6636
V6266
tudents in grade 5–8 classrooms possess a wide range of
b a ck ground know l e d ge . Student response to this video
program is sure to be va ried, so the teachers at these grades
need all the help they can get! This guide has been designed
to help the 5–8 science teacher by providing a brief synopsis of the pro gra m , p rev i ewing and fo l l ow-up questions,
activities, vo c ab u l a ry and additional resources.
Before Viewing: E x t e n s i ve re s e a rch tells how important
it is for the teacher to discover what the students know —
or think they know — about a topic, befo re actually starting a new unit.Therefo re , after prompting discussion with
the pre - v i ewing questions, lead your class to create an
“Everything We Think We Know About…” list.You may also
wish to preview key vo c abulary wo rd s , and have students
raise additional questions they hope will be answered.
After Viewing: Have your students share video excerpts
that fascinated or surprised them, then challenge your students to prove or disprove the accuracy of the facts they
put on their “ E ve rything We Think We Know About…” list.
Discuss what else they learned and use the fo l l ow-up questions and activities to inspire further discussion. E n c o u rage
students to re s e a rch the topic further with the Internet and
reading re s o u rces provided.
Program Summary
nucleus — A membrane-bound structure within a cell that contains the
Humans share the Earth with countless nu m b e rs of microscopic org a n i s m s .
The most simple and numerous of all these organisms are the members of the
scientific kingdom Monera , c o m m o n ly known as bacteria. Bacteria thri ve
eve ry w h e re on the planet — in soil, water and air — even inside other cre at u res! In fa c t , we have billions of harmless bacteria growing in our mouths
alone. Bacteria are the most ancient creatures on Earth and are responsible for
creating the Earth’s bre a t h able atmosphere billions of ye a rs ago. Though
single-celled bacteria are the simplest of living cre a t u res, with no true
nucleus, they are essential for life.
T h ree and a half billion ye a rs ago , Earth’s first living organisms, called arch a ebacteria, thrived in an atmosphere with no ox y ge n . Over time, some bacteri a
began making food through photosynthesis and releasing oxygen as a
by p ro d u c t . Over billions of ye a rs, these bacteria created Earth’s bre a t h able
atmosphere, making life as we know it possible. Some bacteria, called anaerobes, cannot surv i ve in our ox y ge n - rich atmosphere . These re l a t i ves of the
arch a e b a c t e ria can be found in the intestines of animals, deep in compost
piles, in sewers and even around undersea volcanic vents.Aerobic bacteria are
everywhere else!
While most types of bacteria are helpful, t h e re are harmful species that may
cause disease. During World War I, Scottish physician A l exander Fleming discovered the first antibiotic — a substance that kills bacteria. Fleming observed
that something produced by the fungus Penicillium notatum was interfering
with the growth of the harmful bacteria that he was studying. He named this
substance penicillin and befo re long, this drug was re s p o n s i ble for saving
many millions of lives from bacterial infections.
M a ny bacteria are successful because they are able to wrap themselves in a
p ro t e c t i ve coating called an endospore whenever living conditions become
inhospitable.T h ey can stay dormant until conditions improve, even in boiling
and freezing environments.Another reason for their success is their ability to
reproduce so ra p i d ly. B a c t e ria re p roduce asexually; each bacterium replicates
its genetic information, swells up and splits, creating two identical cells. Under
ideal conditions, some bacteria can double their numbers every 20 minutes!
All living things have a partnership with bacteria.The Earth itself depends
upon bacteria as a major agent in decomposition.These decomposers bre a k
down dead plants and animals, recycling their nutrients into the soil for future
use.Animals depend upon bacteria to break down the foods they eat, helping
in the digestion pro c e s s . We also use cultures of bacteria to make cert a i n
fo o d s , such as cheese and yo g u rt. So even though some bacteria cause diseases, they are simply organisms that we simply can’t live without!
genetic information that the cell needs to grow and divide. Bacterium cells do
not have a defined nucleus; their genetic material floats within the cell.
microoganism — A small living thing that cannot be seen without a microscope.
microbe — A microscopic organism like a bacterium.
spirilla (singular: spirillum) — Bacteria that are twisted in shape,
looking like a spiral staircase.
bacillus (plural: bacilli) — A straight, rod-shaped bacterium.
coccus (plural: cocci) — A spherical bacterium.
Alexander Fleming — (1881–1955 CE) The Scottish physician who
observed in 1928 that a substance produced by a fungus could kill bacteri a .
This was the first antibiotic, which he named penicillin.
penicillin — An antibiotic made by the mold species Penicillium notatum.
antibiotic — A drug that interfe res with the growth of bacteri a . Penicillin,
made by mold, was the first antibiotic.
archaebacteria — (Greek – “archae”: “ancient”) Microorganisms found in hars h
environments lacking ox y gen and believed to be among the first to live on Earth.
anaerobic — A wo rd that describes organisms that can survive only in
places where there is no oxygen.
aerobic — A word used to describe organisms that need oxygen to survive.
photosynthesis — The process through which sunlight is trapped and
ch e m i c a l ly combined with water and carbon dioxide to produce sugars and
oxygen.
cell wall — The protective, ri gid outer layer of the cells of plants, f u n gi and
bacteria.
cytoplasm — The jelly l i ke substance that makes up the majority of a living
cell. In bacteria, the genetic info rmation floats in the cytoplasm and is not
contained in a nucleus.
endospore — A stage in the life cycle of some bacteria that can occur when
living conditions are not support i ve . Bacteria can lie dormant for prolonged
periods as endospores, withstanding boiling and freezing.
Pre-viewing Discussion
Befo re students ge n e rate their list of “ E ve r ything We Think We Know
About...” for this topic, stimulate and focus their thinking by raising these
questions so that their list will better reflect the key ideas in this show:
• What was the first life form on Earth?
• Where are bacteria found?
• How do bacteria affect other organisms?
After the class has completed their “ E ve rything We Think We Know
About...” list, ask them what other questions they have that they hope will
be answe red during this pro gra m . H ave students listen cl o s e ly to learn if
everything on their class list is accurate and to hear if any of their own
questions are answered.
Focus Questions
1. Is the purpose of bacteria to make us sick? Explain.
2. Describe three basic shapes of bacteria.
3.Where can bacteria be found?
4. Name some effects of the bacteria staphylococcus.
5.Who was Alexander Fleming? Describe his discovery.
6.What are arch a e b a c t e ria, and what was their contribution to life on
Earth?
7.What is the difference between aerobic and anerobic organisms?
8. Describe the basic structure of a bacterium.
9.What is binary fission? W hy is this method of re p roduction so effe c t i ve
for bacteria?
10. Explain the difference between autotrophs and heterotrophs.
11.Why are bacteria considered to be decomposers? Explain.
12.What are the key conditions for bacteria growth?
asexual reproduction — The creation of new organisms without the
Follow-up Discussion
The following wo rds are included for teacher re fe rence or for use with students. They are listed in the order in which they appear in the video.
bacteria (singular: bacterium) — Simple, single-celled micro o rg a n i s m s
with a cell wa l l , but no cell stru c t u re s .The most nu m e rous and ancient of all
creatures, they contain only cytoplasm and floating genetic information.
Kingdom Monera — The scientific category that includes all simple organisms without a nucleus.
(Continued)
union of two individuals.Asexual reproduction can involve budding, spore formation and fission.
binary fission — A method of asexual re p roduction in which an individual
cell replicates its genetic information, then splits itself into two identical cells.
In bacteria, this doubling can happen every 20 minutes.
conjugation — A method of re p roduction in which one organism tra n s fe rs
hereditary material to another, creating a genetically different cell.
flagella — Little whip-like stru c t u res that help some bacteria to move around.
autotrophs — Organisms that make their own food.
heterotrophs — Organisms that get their food from an outside source.
decomposers — Organisms that are responsible for breaking down organic
matter, decomposing it into simpler form and re c y cling their nutrients into
the soil.
R e s e a rch indicates that students will retain their previous misconceptions
about a topic, in pre fe rence to new information, until they active ly re c o gnize and correct their own erro rs. Therefore, it is important to have yo u r
students re - examine the facts/beliefs they put on their “ E ve rything We
Think We Know About...” list. It might also be helpful to review the list by
m a rking each entry with a “+” or “-” to show which facts we re correct and
which were incorrect.
Thought provoking discussions provide a good way to assess the ove rall
depth of student understanding. The following are some suggested discussion topics.
• Discuss the value of bacteri a . A re bacteria helpful or harmful to Eart h ’s
inhabitants? Explain your reasoning.
• Discuss in what locations bacteria are most like ly to be fo u n d . W hy do
you think so?
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Vocabulary