The document provides an overview of the key concepts in biology and the scientific method covered in Chapter 1. It discusses the goals of science to investigate and explain natural phenomena through observation and experimentation. It introduces concepts like hypotheses, controlled experiments, theories, and the historical experiments disproving spontaneous generation. It also summarizes the characteristics of living things and levels of biological organization. Finally, it briefly describes light and electron microscopes.

1. The Science of
Biology
Chapter 1
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2. Science
• Seeks to investigate, understand, and
explain events in the natural world.
• Seeks to make predictions about the
natural world.
• Begins with observation!
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3. Observation
• Is the process of gathering
information.
• Two Types:
– Quantitative data are expressed by
numbers. Can be counted or measured.
– Qualitative data are descriptive and can’t
be counted or measured.

4. Inference
• An assumption based on information
previously gathered.

5. Hypothesis
• Hypothesis – a proposed scientific
explanation for a set of observations.
– Must be testable!
– May be disproved.
– “Educated Guess”
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6. Controlled Experiment
• Controlled experiment – only one
variable is changed at a time. All
others are controlled.
– Manipulated variable – the one you
change.
– Responding variable – the one that
changes in response.
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7. Spontaneous Generation
• Spontaneous generation – the idea
that living things can arise from non-
living matter.
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8. Redi’s Experiment
• Francesco Redi disproved the
hypothesis of spontaneous generation
with the jars of meat. (see p. 9)
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9. Pasteur’s Experiments
• Louis Pasteur disproved spontaneous
generation of microorganisms.
– Used special s-shaped flasks.
– Boiled the chicken broth to kill germs.
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10. Theories
• Theory – a well-supported hypothesis.
– Unifies a broad range of observations.
– Can be revised/replaced.
– Ex: Theory of evolution, plate tectonics
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11. What is Biology?
• Biology – science that seeks to
understand the living world.
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12. Characteristics of Living
Things
• Made of cells.
• Reproduce.
• Based on genetic code.
• Grow and develop.
• Obtain and use materials and energy.
• Respond to their environment.
• Maintain stable internal environment.
• Change over time.
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13. …made of cells.
• Unicellular or Multicellular.
• Basic unit of living things.
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14. …reproduce.
• Sexual or asexual.
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15. …based on genetic code.
• DNA!
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16. …grow and develop.
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17. …obtain and use materials
and energy.
• Metabolism – the combination of
chemical reactions through which an
organism builds up or breaks down
materials.
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18. …responds to the
environment.
• Stimulus – a signal to which an
organism responds.
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19. …maintains internal balance.
• Homeostasis – the process by which
organisms keep internal conditions
fairly constant.
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20. …changes over time.
• Evolution – changes in organisms over
time.
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21. Levels of Organization
• Study the diagram on p. 21!
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22. Microscopes
• Compound Light Microscopes – allows
light to pass through a specimen and
magnifies the image with lenses.
• Can be used with living specimens.
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23. Microscopes
• Images under a light microscope are
upside-down!
e
e
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24. Microscopes
• Electron microscopes – use beams of
electrons to produce images.
• Three-dimensional images!
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