ProQuest Standards-Based Learning Activity
GO WASH YOUR HANDS:
Exploring the Kingdom Monera (Bacteria) -- Teacher Procedures
APPROPRIATE FOR: Science, Grades 9-12
TIMELINE: Three class periods
SCIENCE Standards Addressed Through This Lesson
NSTA: http://www.educationworld.com/standards/national/science/index.shtml
CONTENT STANDARD A: ABILITIES NECESSARY TO DO SCIENTIFIC INQUIRY
As a result of activities in grades 9-12, all students should:
IDENTIFY QUESTIONS AND CONCEPTS THAT GUIDE SCIENTIFIC INVESTIGATIONS.
Students should formulate a testable hypothesis and demonstrate the logical connections between the scientific concepts guiding a hypothesis and the design of an experiment. They should demonstrate appropriate procedures, a knowledge base, and conceptual understanding of scientific investigations.
DESIGN AND CONDUCT SCIENTIFIC INVESTIGATIONS.
Designing and conducting a scientific investigation requires introduction to the major concepts in the area being investigated, proper equipment, safety precautions, assistance with methodological problems, recommendations for use of technologies, clarification of ideas that guide the inquiry, and scientific knowledge obtained from sources other than the actual investigation.
USE TECHNOLOGY AND MATHEMATICS TO IMPROVE INVESTIGATIONS AND COMMUNICATIONS.
A variety of technologies, such as hand tools, measuring instruments, and calculators, should be an integral component of scientific investigations. The use of computers for the collection, analysis, and display of data is also a part of this standard. Mathematics plays an essential role in all aspects of an inquiry. For example, measurement is used for posing questions, formulas are used for developing explanations, and charts and graphs are used for communicating results.
FORMULATE AND REVISE SCIENTIFIC EXPLANATIONS AND MODELS USING LOGIC AND EVIDENCE.
Student inquiries should culminate in formulating an explanation or model. Models should be physical, conceptual, and mathematical. In the process of answering the questions, the students should engage in discussions and arguments that result in the revision of their explanations. These discussions should be based on scientific knowledge, the use of logic, and evidence from their investigation.
RECOGNIZE AND ANALYZE ALTERNATIVE EXPLANATIONS AND MODELS.
This aspect of the standard emphasizes the critical abilities of analyzing an argument by reviewing current scientific understanding, weighing the evidence, and examining the logic so as to decide which explanations and models are best. In other words, although there may be several plausible explanations, they do not all have equal weight. Students should be able to use scientific criteria to find the preferred explanations.
COMMUNICATE AND DEFEND A SCIENTIFIC ARGUMENT.
Students in school science programs should develop the abilities associated with accurate and effective communication. These include writing and following procedures, expressing concepts, reviewing information, summarizing data, using language appropriately, developing diagrams and charts, explaining statistical analysis, speaking clearly and logically, constructing a reasoned argument, and responding appropriately to critical comments.
CONTENT STANDARD E: ABILITIES OF TECHNOLOGICAL DESIGN
As a result of activities in grades 9-12, all students should:
IDENTIFY A PROBLEM OR DESIGN AN OPPORTUNITY.
Students should be able to identify new problems or needs and to change and improve current technological designs.
PROPOSE DESIGNS AND CHOOSE BETWEEN ALTERNATIVE SOLUTIONS.
Students should demonstrate thoughtful planning for a piece of technology or technique. Students should be introduced to the roles of models and simulations in these processes.
IMPLEMENT A PROPOSED SOLUTION.
A variety of skills can be needed in proposing a solution depending on the type of technology that is involved.
EVALUATE THE SOLUTION AND ITS CONSEQUENCES.
Students should test any solution against the needs and criteria it was designed to meet. At this stage, new criteria not originally considered may be reviewed.
COMMUNICATE THE PROBLEM, PROCESS, AND SOLUTION.
Students should present their results to students, teachers, and others in a variety of ways, such as orally, in writing, and in other forms--including models, diagrams, and demonstrations.
LEARNING EXPECTATION/OBJECTIVES
· Students will explore the kingdom Monera with the assistance of ProQuest.
· Students will discover the method by which bacteria are transferred with the assistance of ProQuest.
MATERIALS (needed per group**)
· 1 or 3 petri dish(es) with Luria broth agar per group, depending on whether the optional activity is undertaken
· 1 incubator/ heat lamp
· Hand soap
· Printer and computer with access to eLibrary, eLibrary Science, SIRS, or Platinum
ACTIVITY PROCESS: DIRECTIONS TO THE TEACHER
Description of Activity
Students will learn about bacteria with an introductory experiment that is hands-on, relates to everyday life and maximizes its impact by disproving some common myths about hand washing. Once the students are drawn in, ProQuest will be used to springboard into more independent and in-depth studies of bacteria. First, students will use ProQuest to sample the spectrum of bacteria and find those that are associated with disease. Second, students will use ProQuest to investigate specific bacterium via articles and easy-to-find photos.
Background Information
What are we trying to accomplish by washing our hands before eating? Many students will suggest that we’re trying to get rid of the germs we pick up during our daily routines. What are those germs and does washing our hands really remove them?
The introductory experiment is pretty straightforward. Have each group of students label one petri dish with their group members’ names and today’s date. As well, have students draw a line down the middle of the petri dish, labeling one side ‘before’ and one side ‘after.’ Each student should then press his/her thumbprint onto the side of the group’s petri dish labeled ‘before.’
Have students then wash their hands using soap (just as they would before eating). Return and have each student press his/her thumbprint onto the side labeled ‘after.’ After 24 hours, results should yield large bacteria colonies. Roughly 70% of the class will have more bacteria ‘after’ washing hands than ‘before.’ Even if ‘before’ and ‘after’ are about the same, this result should still be quite surprising to most students.
The explanation for this unlikely-seeming result is simple. Using soap breaks down the oil that allows bacteria to attach to your fingers. As you wash your hands you are breaking down the oil, allowing more bacteria to transfer easily to and from your hands. While a simple wash may remove noticeable dirt, it does not completely remove all of the bacteria.
No prior information is required for this lesson plan. Ideally, it should be scheduled for an appropriate time in the calendar year to discuss the kingdom Monera. However, if the scientific method is the primary goal, this demonstration can be used at any time.
OUTLINE OF PROCEDURES -- DAY ONE
A simple way to begin is to ask students, “Why do we wash our hands?” Write their responses on the board to generate a list that uses both scientific and informal terminology. Typical responses include germs, dirt, bacteria, preventing sickness, disease, etc. After the list is compiled, transition into a short discussion on bacteria, indicating that these little organisms are the source of the problems they’ve just finished brainstorming. Possible extensions include encouraging the students turn to their neighbors and discuss how they would convey the true size of bacteria to their parents. After the discussion introduce this “simple yet shocking” experiment, which they will soon conduct.
1. In groups of three or four, have students label the back of the petri dish with the group members’ names and the date of the experiment. Carefully, using a marker, they should draw a line down the middle of the petri dish, labeling one side ‘before’ and one side ‘after.’
2. Have students make simple observations on the cleanliness of their own hands. Can they see evidence of the germs they mentioned in the opening discussion?
3. Being sure not to expose the plate to air for a long period of time, have one student hold the plate upside down with the agar facing the ground. (Bacteria exist in the air and it is important that the primary source of bacteria in this experiment is the students’ hands.) Remove the cover and have each student in the group place a thumbprint on the side labeled ‘before.’ Students need only press lightly on the agar plate. Agar is gelatin and will split if too much pressure is applied. Return the lid to the dish.
4. Have each member of the group wash their hands. Provide no further instruction except to “use soap.” Encourage students to perform the type of activities they might normally carry out before dinner but after they’ve washed their hands (for example: drying their hands on their shirt, or picking up a pencil to take down a phone message). These activities will simulate the “real life” of our hands between the time we wash them and the time we use them to eat. It is fine for students to vary in the amount of time and the use of soap or paper towels.
5. Repeat the hand cleanliness observations. Can they see a difference between what their hands look like before and after washing?
6. Have students carry out the same thumbprint procedure as in step three except that this time the thumbprint should be made on the side labeled ‘after.’ Again, be sure to keep the face of the plate down.
7. Place plates in an incubator at 37 degrees Celsius or under a heat lamp for 24 hours. Bacteria will be noticeable only after 24 hours. Colonies of bacteria replicate once every 20 minutes to an hour. Large white or yellow colonies will be seen on the plate after 24 hours.
OUTLINE OF PROCEDURES -- DAY TWO
Begin by having students examine their colony plates. Approximately 70% of the plates will exhibit more growth on the ‘after’ side, demonstrating that there were more bacteria transferred with the hands that had just been washed! Where did these bacteria come from? Have students suggest possible reasons for the event. List them on the board. Students often suggest that more bacteria came from the water, the soap, the plate itself, or even paper towels.
Next discuss the following resources on the importance of hand washing to prevent the spread of infectious diseases. These websites were selected by ProQuest editors:
Mayo Clinic: http://www.mayoclinic.com/health/hand-washing/hq00407
Center for Disease Control: http://www.cdc.gov/cleanhands/
Finally, students will begin their own research of bacteria using ProQuest in order to complete the activity sheet. If time is running short, use the last few minutes as an introduction on how to use and search ProQuest and save the actual research for the next day.
Using ProQuest:
· Enter key words to begin you search.
· Here are some key terms and topics that students might want to try when searching.
a. Hand washing
b. Bacteria infections
c. Disease Causing Bacteria
d. Beneficial Bacteria
e. E. Coli bacteria
OUTLINE OF PROCEDURES-DAY 3
Students should continue their research using ProQuest. Be sure to remind students to focus on the activity sheet questions.
ASSESSMENT
Students will be evaluated based on the following criteria:
1. Did students use ProQuest to collect information regarding bacteria?
2. Did students successfully complete the activity sheet?
OPTIONAL FOLLOW-UP EXPERIMENT
Have students develop and test a new experiment based on the list of variables that they initially believed to have contributed to bacteria growth. (Note that if you intend to offer this activity, you’ll want to delay offering any analysis of the first experiment in order to make this activity not just about proving but also about investigating and exploring.)
a. Have your students generate two lists: one listing all the factors that may have encouraged bacteria growth in the first experiment, and a second listing all the factors that may have inhibited bacteria growth.
b. Review the process of designing an experiment and why it is important to isolate and test for one variable at a time. Ask the students to volunteer explanations for the following terms:
i. Control Group
ii. Experimental Group
iii. Independent Variable
iv. Dependent Variable
c. In either their original groups or similarly sized groups, students should agree on an experiment proposal that would test one of the variables they brainstormed (and only one!). Each experiment may only use two additional agar-filled petri dishes. Possible variables can be determined by having students retrace their steps, looking back on exactly what they did and what they touched before applying their thumb to the agar a second time. Visual diagrams are a welcome part of any proposal.
d. When a group comes to agreement on an experiment, a nominated spokesperson should approach the teacher to “apply for funding.” This process is an opportunity to explain how science research is also often financed by grants that are awarded through a similar proposal process. It can be very healthy to ask the spokesperson to return to their group to clarify, improve or even modify aspects of their proposal. (This often happens to real scientists who attempt to publish in formal scientific journals!)
e. Using the last two petri dishes, students will conduct their experiments to test their hypothesis. Each group member should be able to explain how their experiment only allows one variable to change at a time and why a control group is necessary or unnecessary for their experiment.
GO WASH YOUR HANDS!
Exploring the Kingdom Monera – Student Version
INTRODUCTION:
“Observations in public restrooms have revealed that only about 68 percent of Americans wash up before leaving.” – San Diego Natural History Museum, 2003
Does this disturb you?
Many parents -- maybe even yours -- make their kids wash with soap. Perhaps they explain that hand washing kills germs so that the kids don’t get sick. But are these parents right? We’re going to find out!
To be scientific, our hypothesis must guide our experiment and be very clear. Here’s the hypothesis we are going to test: “If you wash your hands with soap, then you will remove all bacteria from your hands.”[1]
BACKGROUND:
Bacteria are single-celled organisms belonging to the kingdom Monera. Bacteria are responsible for many different diseases and infections (including anthrax, salmonella food poisoning, tuberculosis and tetanus), but they are also very important for our survival. One bacterium in particular, E. Coli, is responsible for the release of several vitamins and minerals in our large intestines. Without them, we would not survive for very long – so never wash your intestines with soapy water!