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Introduction to Biology
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1-
Why a Study of Biology is Important?
Societal
•Medicine
•Public Health
• Worldwide Water Crisis
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1-
Why a Study of Biology is Important?
Philosophical
•Evolution
•Genetics
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1-
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1-
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1-
Why a Study of Biology is Important?
–Personal
• To be informed
• Support your cause
• Make it your life work
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1-
[bahy-ol-uh-jee]
Bio = life
...ology = the study of
Biology is the science that studies
life
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1-
The Scientific Method in Action
 A systematic way of gaining information
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1-
The Scientific Method: Observation
 An observation is a thoughtful and careful
recognition of an event or a fact.
 The careful observation of a phenomenon leads
to a question.
– How does this happen?
– What causes it to occur?
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1-
The Scientific Method:
The Hypothesis
 Hypothesizing
– question an observation
– propose possible solutions to questions based on what
is already understood about the phenomenon
 Hypotheses must:
– be logical
– account for all current information
– make the least possible assumptions
– be testable
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1-
Testing Hypotheses
 Hypotheses need to be tested to see if they are
supported or disproved.
– Disproved hypotheses are rejected
– Hypotheses can be supported but not proven
 Ways to test a hypothesis:
– Gathering relevant historical information
 Retrospective Studies
– Make additional observations from the natural world
– Experimentation
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1-
The Scientific Method:
Experimentation
 Experiments
– rigorous tests to determine if the solutions are supported
 Experiments attempt to recreation an occurrence
– tests whether or not the hypothesis can be supported or
rejected
 There are many types of experiments
– laboratory, clinical trials, surveys, statistical analyses
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1-
Experimental Design
 All experiments have key elements in common:
– Experiments must be controlled
 this means that all aspects except for one variable must be kept
constant
 usually include any two groups.
– Experimental group: variable is altered, independent variable
– Control group: variable is not altered, dependent variable
– Experiments use models to recreate occurrences, but in a
controlled setting
 model organisms, ISS, cohorts
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1-
Experimental Design
 Experiments must:
– use large numbers of subjects and/or must be
repeated several times (replication)
– be independently reproducible
 The validity of experimental results must:
– be tested statistically
 chi-squared test for statistical significance
– be scrutinized by other scientists
 peer reviewed
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1-
Theory
 If the hypothesis is supported by ample experimental data, it
leads to a theory.
 A theory may be defined as a widely accepted, plausible
general statement about a fundamental concept in science.
– The germ theory states that infectious diseases are caused by
microorganisms.
 Many diseases are not caused by microorganisms, so we must be
careful not to generalize theories too broadly.
– Theories continue to be tested
 Exceptions identified
 Modifications made
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1-
A Scientific Law
 A scientific law is a uniform and constant fact of nature that
describes what happens in nature.
– An example: All living things come from pre-existing living things.
 Scientific laws promote the process of generalization.
– Inductive reasoning
– Since every bird that has been studied lays eggs, we can generalize
that all birds lay eggs.
 Once a theory becomes established, it can be used to
predict specific facts.
– Deductive reasoning
– We can predict that a newly discovered bird species will lay eggs.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1-
Scientific Communication
 Data is shared with the
scientific community through
research articles published in
scientific journals.
– peer review
 Scientists present preliminary
data at conferences.
 Scientists collaborate directly by
phone and
e-mail.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1-
A Sample Experiment
Scientific American August 2010
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1-
A Sample Experiment
 Article: Hardt, Marah J. and Safina, Carl. “Threatening Ocean Life from
the Inside Out.” Scientific American August 2010: Vol. 303 2.
 What types of observations were being made?
 State a hypothesis that was tested.
 Describe an experiment that was conducted.
 Discuss a variable that was studied and describe how constants
where maintained in the experiment.
 How was a model system was used to simulate the conditions being
studied.
 How were the complex processes being studied reduced to their
simplest parts?
 What was learned from the experiments?
20
The Science of Biology
• Chapter 1
21
1.1 The Science of Life
• Biology unifies much of natural life
• Biology attempts to define life
• Biology Living reveals a hierarchical
organization of living systems
2
22
Properties of Life
• Living organisms:
– are composed of cells (Cellular Organization)
– are complex and ordered (Ordered Complexity)
– respond to their environment (Sensitivity)
– can Grow, Develop and Reproduce
– obtain and use energy (Energy Utilization)
– maintain internal balance (Homeostasis)
– allow for Evolutionary Adaptation
• The definitions of life are adapting with the field
- where do viruses fit in?
23
Levels of Organization
1. Cellular Level
• Atoms molecules organelles cells
2. Organismal Level
• Tissues organs organ systems
3.Population Level
• Population species biological community
4. Ecosystem Level
• Biological community + physical habitat (soil, water,
atmosphere)
5. The Biosphere
• The entire planet thought of as an ecosystem
4
24
Levels of Organization
• Cellular Organization
•
cells
• organelles
• molecules
• atoms
• The cell is the
• basic unit of life.
Fig. 1.1-1
6
26
Levels of Organization
• Organismal Level
•
organism
• organ systems
• organs
• tissues
Fig. 1.1-2
8
28
Levels of Organization
• Population Level
•
ecosystem
• community
• species
• population
Fig. 1.1-3
10
30
Levels of Organization
• Each level of organization builds on the
level below it but often demonstrates new
features
• Emergent properties: new properties
present at one level that are not seen in
the previous level
• New properties emerging may be greater
than the sum of the the parts
31
1.2 The Nature of Science
• Science aims to understand the natural
world through observation and reasoning
• Science begins with observations,
therefore, much of science is purely
descriptive
• Science uses both deductive and
inductive reasoning
32
The Nature of Science
• Deductive reasoning uses general
principles to make specific predictions.
• Inductive reasoning uses specific
observations to develop general
conclusions.
33
The Nature of Science
• Scientists use a systematic approach to
gain understanding of the natural world:
– Observation
– Hypothesis formation
– Prediction
– Experimentation
– Conclusion
34
The Nature of Science
• A hypothesis is a possible explanation for
an observation.
• A hypothesis:
– must be tested to determine its validity
– is often tested in many different ways
– allows for predictions to be made
35
The Nature of Science
• The experiment:
– tests the hypothesis
– must be carefully designed to test only
one variable at a time
– consists of a test experiment and a
control experiment
36
The Nature of Science
• If the hypothesis is valid, the scientist can
predict the result of the experiment
• Conducting the experiment to determine if
it yields the predicted result is one way to
test the validity of the experiment
37
Think Like a Scientist
38
The Nature of Science
• Scientists may use:
– reductionism - to break a complex
process down to its simpler parts
– models – to simulate phenomena
that are difficult to study directly
39
Test the early hypothesis of
Spontaneous Generation
Fig. 1.4
40
The Nature of Science
• A scientific theory:
– is a body of interconnected
concepts
– is supported by much experimental
evidence and scientific reasoning
– expresses ideas of which we are
most certain
41
1.3 An Example of Scientific
Inquiry: Darwin and Evolution
• Charles Darwin served as naturalist on
mapping expedition around coastal South
America.
• Used many observations to develop his
ideas
• Proposed that evolution occurs by
natural selection
42
Voyage of the Beagle
43
Charles Darwin
• Evolution: Modification of a species over
generations
– “descent with modification”
• Natural Selection: Individuals with
superior physical or behavioral
characteristics are more likely to survive
and reproduce than those without such
characteristics
44
Darwin’s Evidence
• Similarity of related species
– Darwin noticed variations in related species
living in different locations
45
Unnatural Selection
46
Darwin’s Evidence
• Thomas Malthus:
• Population growth vs. availability of
resources
• -population growth
• is geometric
• -increase in food
• supply is arithmetic
47
Darwin’s Evidence
• Population growth vs. availability of
resources
• Darwin realized that not all members of a
population survive and reproduce
• Deduced that the organisms best adapted
to obtaining resources would survive to
reproduce
• Darwin based these ideas on the writings
of Thomas Malthus
48
Post-Darwin Evolution Evidence
• Fossil record
– Intermediate Organisms
• Mechanisms of heredity
–- Early criticism of Darwin’s ideas were
resolved by Mendel’s theories for genetic
inheritance
49
Post-Darwin Evolution Evidence
• Comparative anatomy
• - Homologous structures have same
evolutionary origin, but different structure
and function.
• - Analogous structures have similar
structure and function, but different
evolutionary origin.
50
Homologous Structures
51
Post-Darwin Evolution Evidence
• Molecular Evidence
• - Our increased
understanding of
DNA and protein
structures has led to
the development of
more accurate
phylogenetic trees.
52
1.4 Unifying Themes in Biology
• Cell theory
• The cell theory describes the organization of
living systems
• All living organisms are made of cells, and
all living cells come from preexisting cells
Fig. 1.11a
Single Celled Organisms
34
Fig. 1.11b
Multi-Cellular Organisms
35
55
1.4 Unifying Themes in Biology
• Molecular basis of inheritance
• The molecular basis of inheritance explains
the continuity of life
• DNA encodes genes which control living
organisms and are passed from one
generation to the next
• The DNA code is similar for all organisms
(The Central Dogma)
Fig. 1.12
37
57
Unifying Themes in Biology
• Structure and Function
• The proper function of a molecule is
dependent on its structure
• The structure of a molecule can often tell
us about its function
• Four major classes of Biomolecules
1. Nucleic Acids
2. Amino Acids
3. Lipids
4. Carbohydrates
58
Unifying Themes in Biology
• Evolutionary Change
• The diversity of life arises by evolutionary
change leading to the present biodiversity we
see
• Biology attempts to classify life’s great
diversity based on these unifying themes
• Currently all living things are classified into 3
Domains subdivided into Kingdoms (more on
taxonomy to come)
• This process is always changing
Fig. 1.13
The Diversity of Life
Three Domains:
1. Eukarya
2. Archaea
3. Bacteria
40
Fig. 1.13-1
Domain Eukarya is
Divided into four
Kingdoms:
1. Plantae
2. Fungi
3. Animalia
4. Protista
41
Fig. 1.13-2
42
Fig. 1.13-3
43
63
Unifying Themes in Biology
• Evolutionary Conservation
• Evolutionary conservation explains the unity
of living systems
• The underlying unity of biochemistry and
genetics argues that all life has evolved from
the same origin event
• Critical characteristics of early organisms are
conserved and passed on to future
generations
Fig. 1.14
Homeodomains
45
65
Unifying Themes in Biology
• Cells are information-processing systems
• Every cell in an organism carries the same
genetic information
• The control of gene expression allows cells
to differentiate into different cell and tissue
types
• Cells also process information received
from the environment and respond to
maintain homeostasis
66
Unifying Themes in Biology
• Emergent properties
• New properties are present at one level of
organization that are not seen in the
previous level
• The whole is greater than the sum of its
parts
67
The Science of Biology
• End Chapter 1

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A Presentation on Introduction to Biology.ppt

  • 2. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1- Why a Study of Biology is Important? Societal •Medicine •Public Health • Worldwide Water Crisis
  • 3. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1- Why a Study of Biology is Important? Philosophical •Evolution •Genetics
  • 4. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1-
  • 5. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1-
  • 6. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1- Why a Study of Biology is Important? –Personal • To be informed • Support your cause • Make it your life work
  • 7. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1- [bahy-ol-uh-jee] Bio = life ...ology = the study of Biology is the science that studies life
  • 8. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1- The Scientific Method in Action  A systematic way of gaining information
  • 9. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1- The Scientific Method: Observation  An observation is a thoughtful and careful recognition of an event or a fact.  The careful observation of a phenomenon leads to a question. – How does this happen? – What causes it to occur?
  • 10. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1- The Scientific Method: The Hypothesis  Hypothesizing – question an observation – propose possible solutions to questions based on what is already understood about the phenomenon  Hypotheses must: – be logical – account for all current information – make the least possible assumptions – be testable
  • 11. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1- Testing Hypotheses  Hypotheses need to be tested to see if they are supported or disproved. – Disproved hypotheses are rejected – Hypotheses can be supported but not proven  Ways to test a hypothesis: – Gathering relevant historical information  Retrospective Studies – Make additional observations from the natural world – Experimentation
  • 12. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1- The Scientific Method: Experimentation  Experiments – rigorous tests to determine if the solutions are supported  Experiments attempt to recreation an occurrence – tests whether or not the hypothesis can be supported or rejected  There are many types of experiments – laboratory, clinical trials, surveys, statistical analyses
  • 13. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1- Experimental Design  All experiments have key elements in common: – Experiments must be controlled  this means that all aspects except for one variable must be kept constant  usually include any two groups. – Experimental group: variable is altered, independent variable – Control group: variable is not altered, dependent variable – Experiments use models to recreate occurrences, but in a controlled setting  model organisms, ISS, cohorts
  • 14. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1- Experimental Design  Experiments must: – use large numbers of subjects and/or must be repeated several times (replication) – be independently reproducible  The validity of experimental results must: – be tested statistically  chi-squared test for statistical significance – be scrutinized by other scientists  peer reviewed
  • 15. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1- Theory  If the hypothesis is supported by ample experimental data, it leads to a theory.  A theory may be defined as a widely accepted, plausible general statement about a fundamental concept in science. – The germ theory states that infectious diseases are caused by microorganisms.  Many diseases are not caused by microorganisms, so we must be careful not to generalize theories too broadly. – Theories continue to be tested  Exceptions identified  Modifications made
  • 16. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1- A Scientific Law  A scientific law is a uniform and constant fact of nature that describes what happens in nature. – An example: All living things come from pre-existing living things.  Scientific laws promote the process of generalization. – Inductive reasoning – Since every bird that has been studied lays eggs, we can generalize that all birds lay eggs.  Once a theory becomes established, it can be used to predict specific facts. – Deductive reasoning – We can predict that a newly discovered bird species will lay eggs.
  • 17. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1- Scientific Communication  Data is shared with the scientific community through research articles published in scientific journals. – peer review  Scientists present preliminary data at conferences.  Scientists collaborate directly by phone and e-mail.
  • 18. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1- A Sample Experiment Scientific American August 2010
  • 19. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1- A Sample Experiment  Article: Hardt, Marah J. and Safina, Carl. “Threatening Ocean Life from the Inside Out.” Scientific American August 2010: Vol. 303 2.  What types of observations were being made?  State a hypothesis that was tested.  Describe an experiment that was conducted.  Discuss a variable that was studied and describe how constants where maintained in the experiment.  How was a model system was used to simulate the conditions being studied.  How were the complex processes being studied reduced to their simplest parts?  What was learned from the experiments?
  • 20. 20 The Science of Biology • Chapter 1
  • 21. 21 1.1 The Science of Life • Biology unifies much of natural life • Biology attempts to define life • Biology Living reveals a hierarchical organization of living systems 2
  • 22. 22 Properties of Life • Living organisms: – are composed of cells (Cellular Organization) – are complex and ordered (Ordered Complexity) – respond to their environment (Sensitivity) – can Grow, Develop and Reproduce – obtain and use energy (Energy Utilization) – maintain internal balance (Homeostasis) – allow for Evolutionary Adaptation • The definitions of life are adapting with the field - where do viruses fit in?
  • 23. 23 Levels of Organization 1. Cellular Level • Atoms molecules organelles cells 2. Organismal Level • Tissues organs organ systems 3.Population Level • Population species biological community 4. Ecosystem Level • Biological community + physical habitat (soil, water, atmosphere) 5. The Biosphere • The entire planet thought of as an ecosystem 4
  • 24. 24 Levels of Organization • Cellular Organization • cells • organelles • molecules • atoms • The cell is the • basic unit of life.
  • 26. 26 Levels of Organization • Organismal Level • organism • organ systems • organs • tissues
  • 28. 28 Levels of Organization • Population Level • ecosystem • community • species • population
  • 30. 30 Levels of Organization • Each level of organization builds on the level below it but often demonstrates new features • Emergent properties: new properties present at one level that are not seen in the previous level • New properties emerging may be greater than the sum of the the parts
  • 31. 31 1.2 The Nature of Science • Science aims to understand the natural world through observation and reasoning • Science begins with observations, therefore, much of science is purely descriptive • Science uses both deductive and inductive reasoning
  • 32. 32 The Nature of Science • Deductive reasoning uses general principles to make specific predictions. • Inductive reasoning uses specific observations to develop general conclusions.
  • 33. 33 The Nature of Science • Scientists use a systematic approach to gain understanding of the natural world: – Observation – Hypothesis formation – Prediction – Experimentation – Conclusion
  • 34. 34 The Nature of Science • A hypothesis is a possible explanation for an observation. • A hypothesis: – must be tested to determine its validity – is often tested in many different ways – allows for predictions to be made
  • 35. 35 The Nature of Science • The experiment: – tests the hypothesis – must be carefully designed to test only one variable at a time – consists of a test experiment and a control experiment
  • 36. 36 The Nature of Science • If the hypothesis is valid, the scientist can predict the result of the experiment • Conducting the experiment to determine if it yields the predicted result is one way to test the validity of the experiment
  • 37. 37 Think Like a Scientist
  • 38. 38 The Nature of Science • Scientists may use: – reductionism - to break a complex process down to its simpler parts – models – to simulate phenomena that are difficult to study directly
  • 39. 39 Test the early hypothesis of Spontaneous Generation Fig. 1.4
  • 40. 40 The Nature of Science • A scientific theory: – is a body of interconnected concepts – is supported by much experimental evidence and scientific reasoning – expresses ideas of which we are most certain
  • 41. 41 1.3 An Example of Scientific Inquiry: Darwin and Evolution • Charles Darwin served as naturalist on mapping expedition around coastal South America. • Used many observations to develop his ideas • Proposed that evolution occurs by natural selection
  • 43. 43 Charles Darwin • Evolution: Modification of a species over generations – “descent with modification” • Natural Selection: Individuals with superior physical or behavioral characteristics are more likely to survive and reproduce than those without such characteristics
  • 44. 44 Darwin’s Evidence • Similarity of related species – Darwin noticed variations in related species living in different locations
  • 46. 46 Darwin’s Evidence • Thomas Malthus: • Population growth vs. availability of resources • -population growth • is geometric • -increase in food • supply is arithmetic
  • 47. 47 Darwin’s Evidence • Population growth vs. availability of resources • Darwin realized that not all members of a population survive and reproduce • Deduced that the organisms best adapted to obtaining resources would survive to reproduce • Darwin based these ideas on the writings of Thomas Malthus
  • 48. 48 Post-Darwin Evolution Evidence • Fossil record – Intermediate Organisms • Mechanisms of heredity –- Early criticism of Darwin’s ideas were resolved by Mendel’s theories for genetic inheritance
  • 49. 49 Post-Darwin Evolution Evidence • Comparative anatomy • - Homologous structures have same evolutionary origin, but different structure and function. • - Analogous structures have similar structure and function, but different evolutionary origin.
  • 51. 51 Post-Darwin Evolution Evidence • Molecular Evidence • - Our increased understanding of DNA and protein structures has led to the development of more accurate phylogenetic trees.
  • 52. 52 1.4 Unifying Themes in Biology • Cell theory • The cell theory describes the organization of living systems • All living organisms are made of cells, and all living cells come from preexisting cells
  • 53. Fig. 1.11a Single Celled Organisms 34
  • 55. 55 1.4 Unifying Themes in Biology • Molecular basis of inheritance • The molecular basis of inheritance explains the continuity of life • DNA encodes genes which control living organisms and are passed from one generation to the next • The DNA code is similar for all organisms (The Central Dogma)
  • 57. 57 Unifying Themes in Biology • Structure and Function • The proper function of a molecule is dependent on its structure • The structure of a molecule can often tell us about its function • Four major classes of Biomolecules 1. Nucleic Acids 2. Amino Acids 3. Lipids 4. Carbohydrates
  • 58. 58 Unifying Themes in Biology • Evolutionary Change • The diversity of life arises by evolutionary change leading to the present biodiversity we see • Biology attempts to classify life’s great diversity based on these unifying themes • Currently all living things are classified into 3 Domains subdivided into Kingdoms (more on taxonomy to come) • This process is always changing
  • 59. Fig. 1.13 The Diversity of Life Three Domains: 1. Eukarya 2. Archaea 3. Bacteria 40
  • 60. Fig. 1.13-1 Domain Eukarya is Divided into four Kingdoms: 1. Plantae 2. Fungi 3. Animalia 4. Protista 41
  • 63. 63 Unifying Themes in Biology • Evolutionary Conservation • Evolutionary conservation explains the unity of living systems • The underlying unity of biochemistry and genetics argues that all life has evolved from the same origin event • Critical characteristics of early organisms are conserved and passed on to future generations
  • 65. 65 Unifying Themes in Biology • Cells are information-processing systems • Every cell in an organism carries the same genetic information • The control of gene expression allows cells to differentiate into different cell and tissue types • Cells also process information received from the environment and respond to maintain homeostasis
  • 66. 66 Unifying Themes in Biology • Emergent properties • New properties are present at one level of organization that are not seen in the previous level • The whole is greater than the sum of its parts
  • 67. 67 The Science of Biology • End Chapter 1