Page 1 Investigating Spontaneous Generation Fisher Catalog # S32620 Neo Science No $98.95 Refill $27.45
Page 2 Kit consists of 2 activities 1.Recreating Pasteur’s Experiment 2. Observing Bacteria Under the Microscope
Page 3 Objective Objective Replicate Louis Pasteur’s classic experiment on spontaneous generationReplicate Louis Pasteur’s classic experiment on spontaneous generation Investigate weather spontaneous generation can occur on Earth todayInvestigate weather spontaneous generation can occur on Earth today Define and recognize the characteristics of ‘Life ’’Define and recognize the characteristics of ‘Life ’’
Page 4 Materials 10 Test tubes10 Test tubes Plastic pipetsPlastic pipets Coverslips Coverslips Loeffler’s Methylene BlueLoeffler’s Methylene Blue Rubber stopper sRubber stopper s Microscope slidesMicroscope slides 500 mL Nutrient broth media500 mL Nutrient broth media S-shaped glass tubeS-shaped glass tube Straight glass tubeStraight glass tube
Page 5 When to fit this into the curriculum When to fit this into the curriculum A differnt angle introducing Microscope use and practice Microscope use and practice Lab equipmentLab equipment The advancements in Biology aided from the scientific use of the microscope The advancements in Biology aided from the scientific use of the microscope Introduction to prokaryotic cellsIntroduction to prokaryotic cells
Page 6 Background Information Background Information , Antoine van Leeuwenhoek described live microorganisms that he observed in teeth scrapings, rain water, and peppercorn infusions , Antoine van Leeuwenhoek described live microorganisms that he observed in teeth scrapings, rain water, and peppercorn infusions. Maggots were often observed appearing on rotting meat or fishMaggots were often observed appearing on rotting meat or fish Both pieces of evidence formed the widely believed idea of spontaneous generation in the seventeenth centuryBoth pieces of evidence formed the widely believed idea of spontaneous generation in the seventeenth century
Page 7 The hypothesis that living organisms arise from nonliving matter is called spontaneous generation. According to spontaneous generation, a “vital force’ forms life.The hypothesis that living organisms arise from nonliving matter is called spontaneous generation. According to spontaneous generation, a “vital force’ forms life. The Alternative hypothesis, that the living organisms arise from preexisting life, is called biogenesis.The Alternative hypothesis, that the living organisms arise from preexisting life, is called biogenesis.
Page 8 Louis Pasture Louis Pasture 1861: Louis Pasteur demonstrated that microorganisms are present in the air.1861: Louis Pasteur demonstrated that microorganisms are present in the air. ConditionsResults Nutrient broth placed in flask, heated, not sealed Microbial growth Nutrient broth placed in flask, heated, then sealed No microbial growth
Page 9 Pasteur’s S-shaped flask kept microbes out but let air in. The Theory of Biogenesis Figure 1.3
Page 10 Label one test tube A and the other B.Label one test tube A and the other B. Pour 25mL of nutrient broth media in each test tube.Pour 25mL of nutrient broth media in each test tube. Place a rubber stopper with the s- curve tubing on Tube B.Place a rubber stopper with the s- curve tubing on Tube B. Place a rubber stopper with the straight glass tubing on Tube A.Place a rubber stopper with the straight glass tubing on Tube A.Procedure Figure 1.3
Page 11 Place both test tubes in a boiling water bath. Allow the water to boil for about 20 minutes.Place both test tubes in a boiling water bath. Allow the water to boil for about 20 minutes. Remove test tubes from the water bath and allow to cool.Remove test tubes from the water bath and allow to cool. Place test tubes in an incubator set at 37°C, or warm area of classroom.Place test tubes in an incubator set at 37°C, or warm area of classroom. Observe the appearance of broth daily for 6-7 days.Observe the appearance of broth daily for 6-7 days. Figure 1.3
Page 12 Worth a try? Figure 1.3