Ch. 1 Presentation 1406

1. Principles of Biology
Starts with questions.
Am I in the correct class?
Do I need to write this down?
Do I have to buy the book?
Will we have lab today?

2. What is science?

3. What is biology?

4. WHY?

7. Scientific Literacy
The knowledge and understanding of scientific
concepts and processes required for personal
decision making, participation in civic and cultural
affairs, and economic productivity.
http://blogs.discovermagazine.com/intersection/2009/03/17/what-is-scientific-literacy/#.Wa8FvrKGOCh

8. 1-8
Chapter 1
The Scientific Study of Life
©Franco Banfi/WaterF/age fotostock
©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom.
No reproduction or further distribution permitted without the prior written consent of McGraw-Hill Education.

9. Objectives - What is Life?
• Define life and describe how it is organized
• List and describe the characteristics of life
• List the tenets of cellular theory and describe their importance to
Biology
• Be able to explain homeostasis, feedback loops and their
importance to Biology
• List and describe the characteristics of science
• Differentiate between observations, hypotheses, theories and laws
• List and describe the scientific method and how biology is
investigated
• Recognize a controlled experiment, variables, and controls

10. What is Life?

11. • Organized
• Requires energy
• Homeostasis
• Reproduction, growth, and development
• Evolution

12. Section 1.1 Figure 1.2
CELL
The Characteristics of Life
Life is organized
ORGANELLE
MOLECULE
ATOM

13. Figure 1.2
Organization

14. Endothelial
cell
Sheet of
endothelial
cells
Capillary
Endothelial
cellRed blood
cell
The Characteristics of Life
Life is organized
Emergent properties arise at each
level of biological organization.
Section 1.1 Figure 1.3
Ex. The capillary has properties that
its components alone lack.

15. Section 1.1
The Characteristics of Life
Life requires energy
Energy
from
sunlight
Heat
Heat
Heat
Heat
Figure 1.4
Producers
Consumers
Decomposers

16. Section 1.1
The Characteristics of Life
Life maintains internal constancy
Homeostasis

17. Figure 1.5
Homeostasis

18. © 2013 Pearson Education, Inc.
Homeostasis Defined

19. There are 2 Types of Homeostatic Control Mechanisms
© 2013 Pearson Education, Inc.
1. Negative Feedback:
2. Positive Feedback:

21. Section 1.1
The Characteristics of Life
Life reproduces, grows, and develops
Figure 1.6Strawberry Plant: © Dorling Kindersley/Getty Images; Swans: ©Jadranko Markoc/flickr/Getty Images RF

22. The Characteristics of Life
Life evolves
How is it that so many organisms
seem perfectly suited to their
environment?
Section 1.1 Figure 1.7Pygmy seahorse © Mark Webster Wwwphoteccouk/Getty Images

23. Figure 1.7
Evolution

24. 1.1 Mastering Concepts
What are the roles of natural selection and
mutations in evolution?
Cownose rays ©Pete Oxford/Minden Pictures

25. Section 1.2
The Tree of Life Includes Three
Main Branches
Taxonomy
Figure 1.9

26. Section 1.2
The Tree of Life Includes Three
Main Branches
Figure 1.9Bacteria: © Kwangshin Kim/Science Source; Archaea: © Ralph Robinson/Visuals Unlimited
DOMAIN BACTERIA DOMAIN ARCHAEA

27. Section 1.2
The Tree of Life Includes Three Main Branches
Figure 1.9Amoeba: © Melba Photo Agency/PunchStock RF
DOMAIN EUKARYA
Protista (multiple kingdoms) Kingdom Animalia
LM
200 μm
Kingdom Fungi Kingdom Plantae

28. Tree of Life
• Taxonomy
• Hierarchical Organization
– Domain (3)
– Kingdom
– Phylum
– Class
– Order
– Family
– Genus
– Specific epithet (species)

29. 1.2 Mastering Concepts
Which kingdoms contain eukaryotic
organisms?
Cownose rays ©Pete Oxford/Minden Pictures

30. Scientists Study
the Natural World

31. Figure 1.10
Scientific
Method

33. Types of Science
Figure 1.11
Scientists test their
hypotheses with
discovery science or
controlled experiments.
Section 1.3 Birdwatcher: U.S. Fish & Wildlife Service/J&K Hollingsworth; Coffee tasters: © Corbis RF

34. Experimental Design
1.
2.
3.
4.

35. Section 1.3
Components of Experiments
Figure 1.11
• Independent variable: what is manipulated
(e.g., type of coffee bean)
• Dependent variable: what is measured
(e.g., amount of caffeine)
• Standardized variable: held constant for all
subjects in an experiment (e.g., mass of
beans)
Well-designed experiments include independent,
dependent, and standardized variables.
Coffee tasters: © Corbis RF

36. Figure 1.12

37. Variables:
• Independent • Dependent
Standardized Variables:

38. Statistics
• Statistically Significant

40. Bias

42. Hypothesis vs. Theory

43. Scientific Thinking:
• Different from other ways of thinking
• Use of evidence to answer questions and test
ideas.
1. Empirical
2. Testable
3. Repeatable

44. Different ways of thinking about
(understanding) the world.

47. Science cannot answer EVERYTHING!

48. What is Science?
• Understanding how nature works, based on
objective evidence that includes reproducible
experimental data and measurements and
observations.
Definition from textbook (Lewis et al. Life)

49. Characteristics of Science
• It is guided by natural law.
• It has to be explained by these natural laws.
• Science is testable against the natural, observable world.
• Its conclusions are tentative, that is, are not necessarily the
final word. (e.g. Science is self-correcting and admits
mistakes).
• It is falsifiable, meaning that science will seek out errors and
correct them. Unlike other philosophies, it’s a self-correcting
system. This is how progress is often made.
• One cannot prove things true or false in science. Probability
plays a role.
• Correlation does not imply Causation.

50. Criteria for Determining Science
• Science is logical and rational
• Science makes well-defined claims
• Scientific hypotheses are falsifiable
• Scientific experiments are repeatable
• Science requires that claims be
examined by peers
• Science views unexplained gaps in
theories with suspicion
• Science requires caution in examining
evidence
• Science requires objectivity (open-
mind)
• Science does not accept coincidence
as proof
• Science does not accept anecdotal
evidence as proof.
• Science relies on measurable,
repeatable evidence.
• Science insists that extraordinary
claims require extraordinary
evidence.
• Absence of evidence is not evidence
of absence.

51. Scientific Method

52. Steps of the Scientific Method
Step 1: Observe, ask causal questions, gather
information

53. Steps of the Scientific Method
Step 2: Hypothesis Formation
• Tentative statement that explains how or why
– If =
– because =
– and =
– then =
• Variables
– Independent variable (treatment) is the one you control
or manipulate
– Dependent variable is the one you observe and/or
measure

54. Steps of the Scientific Method
Step 3: Experiment and Collect Data
• Design an experiment
– Control group vs. experimental group
– Control variables
– Replicates
– Sample size
– Biases and assumptions

55. Steps of the Scientific Method
Step 4: Organize and analyze results
• Do your data agree (support) or disagree (not
supported) with the hypothesis?
– Graphs
– Statistics and probability (p = 0.05)

56. Steps of the Scientific Method
Step 5: Draw conclusions and tell others what
you have found
– Reject or accept the hypothesis
• Richard Feynman (physics), “a scientist should find
himself wrong as quickly as possible”
– Offer explanations
– Form new hypotheses