1. A View of Life
WarmUp Questions
3.What are the eleven levels of biological organization in order from largest to
smallest?
5.Name 4 characteristics of life.
7.Can you differentiate between inductive and deductive reasoning?

2. A View of Life
The phenomenon we call…
LIFE

3. Chapter 01
A View of Life

4. A View of Life
 Biologists use various forms of inquiry to
explore life
 At the heart of science is inquiry
◦ A search for information and explanation, often
focusing on specific questions
 Biology blends two main processes of scientific
inquiry
◦ Discovery science
◦ Hypothesis-based science

5. A View of Life
◦ Describes natural structures and processes as
accurately as possible through careful observation
and analysis of data

6. A View of Life
 Data
◦ Are recorded observations
◦ Can be quantitative or qualitative
Figure 1.24

7. A View of Life
 In inductive reasoning
◦ Scientists derive generalizations based on a large
number of specific observations

8. A View of Life
 In science, inquiry that asks specific questions
◦ Usually involves the proposing and testing of
hypothetical explanations, or hypotheses

9. A View of Life
 In science, a hypothesis
◦ Is a tentative answer to a well-framed question, an
explanation on trial
◦ Makes predictions that can be tested

10. A View of Life
We use simple hypotheses ALL THE TIME
Observations
Questions
Hypothesis # 1: Hypothesis # 2:
Dead batteries Burnt-out bulb
Prediction: Prediction:
Replacing batteries Replacing bulb
will fix problem will fix problem
Test prediction Test prediction
Figure 1.25 Test falsifies hypothesis Test does not falsify hypothesis

11. A View of Life
 In deductive reasoning
◦ The logic flows from the general to the specific
 If a hypothesis is correct
◦ Then we can expect a particular outcome

12. A View of Life
 A scientific hypothesis must have two
important qualities
◦ It must be testable
◦ It must be falsifiable

13. A View of Life
 The scientific method
◦ Is an idealized process of inquiry
 Very few scientific inquiries
◦ Adhere to the “textbook” scientific method

14. A View of Life
 In mimicry
◦ A harmless species resembles a harmful species
Flower fly
(non-stinging)
Honeybee (stinging)
Figure 1.26

15. A View of Life
 In this case study
◦ Mimicry in king snakes is examined
◦ The hypothesis predicts that predators in non–coral
snake areas will attack king snakes more frequently
than will predators that live where coral snakes are
present Scarlet king snake
Key
Range of scarlet king snake
Range of eastern color snake
North
Carolina
South
Carolina
Eastern coral snake
Figure 1.27 Scarlet king snake

16. A View of Life
 To test this mimicry
hypothesis
◦ Researchers made hundreds
of artificial snakes, an
experimental group
resembling king snakes and
a control group of plain
(a) Artificial king snake
brown snakes
Figure 1.28 (b) Brown artificial snake that has been attacked

17. A View of Life
 After a given period
of time Key
Key
% of attacks on artificial king snakes
◦ The researchers % of attacks on brown artificial snakes
collected data that fit a Field site with artificial snakes
key prediction In areas where coral snakes
17%
were absent, most attacks 83%
were on artificial king snakes
X
North XX X
XX
Carolina X
South XX
Carolina X
X X
XX 16%
84%
In areas where coral
snakes were present,
most attacks were on brown
Figure 1.29 artificial snakes

18. A View of Life
 Experiments must be designed to test
◦ The effect of one variable by testing control groups
and experimental groups in a way that cancels the
effects of unwanted variables

19. A View of Life
 Science cannot address supernatural
phenomena
◦ Because hypotheses must be testable and falsifiable
and experimental results must be repeatable

20. A View of Life
 A scientific theory
◦ Is broad in scope
◦ Generates new hypotheses
◦ Is supported by a large body of evidence

21. A View of Life
 Defining Life
◦ Emergent Properties
◦ Organized
◦ Materials and Energy
◦ Response
◦ Reproduce and Develop
◦ Adaptations and Natural Selection
 Biosphere Organization
◦ Human Population
◦ Biodiversity
 Classification
 The Scientific Method
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22. A View of Life
 Living things vs. nonliving objects:
◦ Comprised of the same chemical elements
◦ Obey the same physical and chemical laws
 The cell is the smallest, most basic unit of all
life
◦ Familiar organisms are multicellular
◦ Some cells independent – single-celled organisms
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23. Defining
Life

24. A View of Life
 Emergent Properties – Biological organization
◦ Levels range from extreme micro to global
◦ Each level up:
 More complex than the preceding level
 Properties:
 A superset of preceding level’s properties emerge from
interactions between components
24

25. Levels of Biological
Organization

26. Living Things:
1. Demonstrate Order
2. Self-regulation
3. Growth and Development

27. A View of Life
 Energy - the capacity to do work
◦ The sun:
 Ultimate source of energy for nearly all life on Earth
 Drives photosynthesis
◦ Metabolism - all the chemical reactions in a cell
 Homeostasis - Maintenance of internal conditions
within certain boundaries
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28. Acquiring
Nutrients

29. A View of Life
 Living things detect changes in environment
 Response often involves movement
◦ Vulture can detect and find carrion a mile away
◦ Monarch butterfly senses fall and migrates south
◦ Microroganisms follow light or chemicals
◦ Even leaves of plants follow sun
 Responses collectively constitute behavior
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30. A View of Life
 Organisms live and die
 Must reproduce to maintain population
 Multicellular organisms:
◦ Begins with union of sperm and egg
◦ Developmental instructions encoded in genes
 Composed of DNA
 Long spiral molecule in chromosomes
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31. Rockhopper Penguins &
Offspring

32. A View of Life
 Adaptation
◦ Any modification that makes an organism more
suited to its way of life
◦ Organisms, become modified over time
◦ However, organisms very similar at basic level
 Suggests living things descended from same ancestor
 Descent with modification - Evolution
 Caused by natural selection
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33. A View of Life
 Population - Members of a species within an
area
 Community - A local collection of interacting
populations
 Ecosystem - The communities in an area
considered with their physical environment
 How chemicals are cycled and re-used by organisms
 How energy flows, from photosynthetic plants to top
predators
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34. Terrestrial Ecosystems:
A Grassland

35. Marine
Ecosystems:
A Coral Reef

36. A View of Life
 Ecosystems negatively impacted by human
populations
◦ Destroyed for agriculture, housing, industry, etc.
◦ Degraded and destabilized by pollution
 However, humans depend upon healthy ecosystems
for
◦ Food
◦ Medicines
◦ Raw materials
◦ Other ecosystem processes
36

37. A View of Life
 Biodiversity:
◦ The total number of species (est. 15 million)
◦ The variability of their genes
◦ The ecosystems in which they live
 Extinction:
◦ The death of the last member of a species
◦ Estimates of 400 species/day lost worldwide
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38. A View of Life
 Taxonomy:
◦ The rules for identifying and classifying organisms
◦ Hierarchical levels (taxa) based on hypothesized
evolutionary relationships
◦ Levels are, from least inclusive to most inclusive:
 Species, genus, family, order, class, phylum, kingdom,
and domain
 A level usually includes more species than the level
below it, and fewer species than the one above it
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39. A View of Life 39
Taxon Human Corn
Domain Eukarya Eukarya
Kingdom Animalia Plantae
Phylum Chordata Anthophyta
Class Mammalia Liliopsida
Order Primates Commelinales
Family Hominidae Poacae
Genus Homo Zea
Species H. sapiens Z. mays

40. A View of Life
 Bacteria
◦ Microscopic unicellular prokaryotes
 Archaea
◦ Bacteria-like unicellular prokaryotes
◦ Extreme aquatic environments
 Eukarya
◦ Eukaryotes – Familiar organisms
40

41. Domains:
The Archaea

42. Domains:
The
Bacteria

43. A View of Life
 Archaea – Kingdoms still being worked out
 Bacteria - Kingdoms still being worked out
 Eukarya
◦ Kingdom Protista
◦ Kingdom Fungi
◦ Kingdom Plantae
◦ Kingdom Animalia
43

44. Domains:
The Eukaryote
Kindoms

45. A View of Life
 Binomial nomenclature (two-word namess)
 Universal
 Latin-based
◦ First word represents genus of organism
◦ Second word is specific epithet of a species within
the genus
◦ Always Italicized asa Genus species (Homo sapiens)
◦ Genus may occur alone (Homo), but not specific
epithet
45

46. A View of Life
 Begins with observation
◦ Scientists use their five senses
◦ Instruments can extend the range of senses
 Hypothesis
◦ A tentative explanation for what was observed
◦ Developed through inductively reasoning from
specific to general
46

47. The Scientific
Method:
A Flow Diagram

48. A View of Life
 Experimentation
◦ Purpose is to challenge the hypothesis
◦ Designed through deductively reasoning from
general to specific
◦ Often divides subjects into a control group and an
experimental group
◦ Predicts how groups should differ if hypothesis is
valid
 If prediction happens, hypothesis is unchallenged
 If not, hypothesis is unsupportable
48

49. A View of Life
 Results
◦ Observable, objective results from an experiment
◦ Strength of the data expressed in probabilities
◦ The probability that random variation could have
caused the results
 Low probability (less than 5%) is good
 Higher probabilities make it difficult to dismiss
random chance as the sole cause of the results
49

50. A View of Life
 The results are analyzed and interpreted
 Conclusions are what the scientist thinks
caused the results
 Findings must be reported in scientific
journals
 Peers review the findings and the conclusions
 Other scientists then attempt to duplicate or
dismiss the published findings
50

51. A View of Life
 Scientific Theory:
◦ Joins together two or more related hypotheses
◦ Supported by broad range of observations,
experiments, and data
 Scientific Principle / Law:
◦ Widely accepted set of theories
◦ No serious challenges to validity
51

52. A View of Life
 Experimental (Independent) variable
◦ Applied one way to experimental group
◦ Applied a different way to control group
 Response (dependent) variable
◦ Variable that is measured to generate data
◦ Expected to yield different results in control versus
experimental groups
52

53. A View of Life
 Observations:
◦ Nitrate fertilizers boost grain crops, but may
damage soils
◦ When grain crops are rotated with pigeon pea it
adds natural nitrogen
 Hypothesis:
◦ Pigeon pea rotation will boost crop production as
much as nitrates
◦ Pigeon pea rotation will NOT damage soils
53

54. Root
Nodules

55. A View of Life
 Experimental Design
◦ Control Group
 Winter wheat planted in pots without fertilizer
◦ Experimental Groups
 1-Winter wheat planted in pots with 45 kg/ha nitrate
 2-Winter wheat planted in pots with 90 kg/ha nitrate
 3-Winter wheat planted in pots that had grown a crop
of pigeon peas
◦ All groups treated identically except for above
55

56. Crop Rotation
Study

57. A View of Life
 Experimental Prediction:
◦ Wheat production following pigeon pea rotation will
be equal or better than following nitrate fertilizer
 Results
◦ 45 kg/ha produced slightly better than controls
◦ 90 kg/ha produced nearly twice as much as
controls
◦ Pigeon pea rotation did not produce as much as the
controls
57

58. A View of Life
 Conclusion
◦ Research hypothesis was not supported by results
◦ However, research hypothesis was not proven false
by negative results
 Revised experiment
◦ Grow wheat in same pots for several generations
◦ Look for soil damage in nitrate pots and improved
production in pigeon pea pots
58

59. A View of Life
 Results
◦ After second year:
 Production following nitrates declined
 Production following pigeon pea rotation was greatest
of all
◦ After third year
 Pigeon pea rotation produced 4X as much as controls
 Revised conclusions
◦ Research hypothesis supported
◦ Pigeon pea rotation should be recommended over
nitrates
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60. A Field Study

61. A View of Life
 Defining Life - Emergent Properties
◦ Materials and Energy
◦ Reproduction and Development
◦ Adaptations and Natural Selection
 Biosphere Organization
◦ Human Population
◦ Biodiversity
 Classification
 The Scientific Method
61

62. Ending Slide Chapter 01
A View of Life