1. The Science of Biology Chapter 1 Pages 2 - 33 Updated July 5, 2004
Created by C. Ippolito
July 5, 2004

2. What is the goal of science? Chapter 1 Section 1 Pages 3 - 7
What is Science
What is the goal of science?
Chapter 1 Section 1
Pages 3 - 7
Updated July 5, 2004
Created by C. Ippolito
July 5, 2004

3. What Science Is and Is Not
examines the natural world;
collects and organizes information in an orderly manner;
Looks for patterns and connections between events;
Proposes explanations that can be tested.
Updated July 5, 2004
Created by C. Ippolito
July 5, 2004

4. Science Consists of two major parts:
It is an organized process that uses evidence to learn about the natural world;
It is the body of knowledge that has been built up using the process.
Updated July 5, 2004
Created by C. Ippolito
July 5, 2004

5. Thinking Like a Scientist
Scientists begin with:
Observation – information gathered using the senses.
Data – information gathered by observing.
Quantitative – presented as numbers (counted or measured).
Qualitative – presented as descriptions, involve characteristics that can’t be counted or measured.
Inference – logical interpretation of data based on prior knowledge or experience.
Updated July 5, 2004
Created by C. Ippolito
July 5, 2004

6. Explaining and Interpreting Evidence
Hypothesis – is a proposed scientific explanation that can be tested for a set of observations.
Hypotheses are tested by:
Controlled experiments
Gathering more data
Updated July 5, 2004
Created by C. Ippolito
July 5, 2004

7. Science as a Way of Knowing
Science always changes:
New tools, techniques, discoveries
Existing ideas questioned and retested
New hypotheses formed
Scientific view:
Universe is a collection of parts and processes that interact
Interaction governed by basic natural laws
Updated July 5, 2004
Created by C. Ippolito
July 5, 2004

8. Science and Human Values
Goals of science:
to understand the natural world;
to explain natural world;
Use explanations to predict and improve quality of life
Bioethics:
Considers how discoveries affect
Moral principles
Social laws
Updated July 5, 2004
Created by C. Ippolito
July 5, 2004

9. How Scientists Work How do scientists test hypotheses?
How does a scientific theory develop?
Chapter 1 Section 2
Pages
Updated July 5, 2004
Created by C. Ippolito
July 5, 2004

10. Scientific Method Aristotle’s Method Modern Method Ask Question
Make Observations
Form Hypothesis
Explain with Reason
Form Conclusion
Modern Method
Ask Question
Make Observations
Form Hypothesis
Test by Experiment
Record and Analyze Results
Form Conclusion
Updated July 5, 2004
Created by C. Ippolito
July 5, 2004

11. Setting Up a Controlled Experiment
Variables – factors that can change results (equipment used, type of material, amount of material, temperature, light, and time)
Manipulated (Independent) Variable – changed to see its effect
Responding (Dependent) Variable – observation changes in response to the manipulated variable
Updated July 5, 2004
Created by C. Ippolito
July 5, 2004

12. Controlled Experiment
Process used to test a hypothesis.
Only one variable is changed at a time.
All other variables are unchanged or controlled.
Updated July 5, 2004
Created by C. Ippolito
July 5, 2004

13. Where Do Living Things Originate
Spontaneous Generation (Abiogenesis)
Life can come from non living material
Mice from grain
Bees from dead bull
Maggots from meat
Scientists:
Aristotle
Needham
Biogenesis
Life can only come from preexisting life
Scientists:
Redi
Spallanzani
Pasteur
Updated July 5, 2004
Created by C. Ippolito
July 5, 2004

14. Redi Experiment (Biogenesis)
Francesco Redi – 1668 Italy
Problem: How do maggots appear on meat?
Hypothesis: If flies cannot reach meat, then maggots will not form.
Manipulated (Independent) Variable – covered jars
Responding (Dependent) Variable – maggots do not appear on meat
Updated July 5, 2004
Created by C. Ippolito
July 5, 2004

15. Updated July 5, 2004
Created by C. Ippolito
July 5, 2004

16. Anton Leeuwenhoek’s Discovery
Dutch lens maker invented simple microscope
Found “animalicules” in rain water
spontaneous generation?
Updated July 5, 2004
Created by C. Ippolito
July 5, 2004

17. Needham Experiment (abiogenesis)
John Needham – mid 1700 England
Problem: Can animalicules arise from gravy?
Hypothesis: If heat kills all existing life in the gravy then animalcules can form from gravy.
Manipulated (Independent) Variable – heated and sealed flasks
Responding (Dependent) Variable – animalicules appear in flasks
Updated July 5, 2004
Created by C. Ippolito
July 5, 2004

18. Spallanzani’s Experiment (biogenesis)
Lazzaro Spallanzani – mid 1700 Italy
Problem: Microorganisms can only arise from other microorganisms in the gravy?
Hypothesis: If heat kills all existing life in the gravy then sealed flasks will not have microorganisms.
Manipulated (Independent) Variable – heated and sealed flasks
Responding (Dependent) Variable – microorganism did not appear in flasks
Vital Force of Air not allowed in!!!
Updated July 5, 2004
Created by C. Ippolito
July 5, 2004

19. Pasteur’s Experiment (biogenesis)
Louis Pasteur – 1864 France
Problem: Microorganisms can only arise from other microorganisms carried by the air into flasks?
Hypothesis: If heat kills all existing life in the gravy and only air is allowed in then flasks will not have microorganisms.
Manipulated (Independent) Variable – heated swan necked flasks
Responding (Dependent) Variable – microorganisms did not appear in flasks
Updated July 5, 2004
Created by C. Ippolito
July 5, 2004

20. How a Theory Develops Theory well tested explanation
repeatedly verified by many scientists
applies to broad range of observations
Updated July 5, 2004
Created by C. Ippolito
July 5, 2004