1. Chapter 1
The Science of Biology

2. What is SCIENCE?
Science: A process of investigation, using observation, experimentation and reasoning.
Experimentation must be objective and reproducible!
Science has limitations-it is not always absolutely and eternally correct!!

3. Science vs. Non-science
Biology
Chemistry
Geology
Physics
Meteorology
Art
Astrology
Philosophy
Religion
Extrasensory Perception

4. Biology
The study of living things

5. Biology includes…. Evolution Ecology Behavior Genetics Diversity
Anatomy
Microbiology

6. Biology studies living things….
What does it mean to be “living”?

7. Characteristics of Life
What qualifies something as “living” versus “non-living?”
Consider these points
complexity
movement
response to stimulation
A life-defining property must be exclusive to living things
Prompt students to decide what properties the living things in the kingdoms have? Are those properties exclusive to living things? What properties are?

8. LIVING from non-living things?
How do you determine
LIVING from non-living things?
Use the paper provided to record whether each of the following slides shows a living or non-living object!

9. Properties of Life All living things share five basic properties:
Cellular organization
Metabolism
Homeostasis
Growth and Reproduction
Heredity

10. 5 Basic Properties of Life
1. Cellular organization
all living things are comprised of at least one cell
single cell (bacteria) up to trillions of cells (human)
Smallest level of organization that can be considered “alive”
Membrane-bound
May contain organelles
Explained by the Cell Theory
All organisms share 5 properties that are unique to life.

11. 5 Basic Properties of Life
2. Metabolism
all living things process energy which is used to power other processes
Energy source can vary
Autotrophs
Heterotrophs
Nutrients are turned into energy through cellular processes
Photosynthesis
Cellular respiration
Glycolysis
Krebs Cycle

12. 5 Basic Properties of Life
3. Homeostasis
all living things maintain stable internal environments to optimize conditions for metabolism and other processes

13. 5 Basic Properties of Life
4. Growth and reproduction
all organisms have the capacity for growth and reproduction
Often a trade-off between the two
Different life-strategies
Semelparity vs. Iteroparity

14. Basic Properties of Life
5. Heredity
all organisms pass genetic information across generations from parents to offspring
Theory of Heredity
Gregor Mendel
Gene Theory

15. Properties of Life All living things share five basic properties:
Cellular organization
Metabolism
Homeostasis
Growth and Reproduction
Heredity

16. Taxonomy Living things are very diverse…
Scientists need a system to name and classify things!
We call this system….
Taxonomy

17. Taxonomy Began with Linnaeus Binomial nomenclature
Genus + species
(ie) Homo sapiens
Hierarchical Classification
(Domain)
Kingdom
Phylum
Class
Order
Family
Genus
species

18. Taxonomy Mnemonics! Kingdom Phylum Class Order Family Genus species
Keep
Patty’s
Class (in)
Order
For
Goodness
sake!
King
Phillip
Came
Over
For
Good
spaghetti!

19. The Six Kingdoms of Life
Scientists group organisms based on similarities into six kingdoms
Archaea
Bacteria
Protista
Fungi
Plantae
Animalia

20. Classifying Life’s Diversity
Each of the six kingdoms are assigned, on the basis of cell structure into one of three domains
Bacteria
Archaea
Eukarya

21. Classification of living things
Taxonomy
Identifying and classifying organisms according to specific criteria
Each taxon is more exclusive than the one before it
Ultimately, each organism has its own Genus species combination that includes a unique set of traits
e.g. Homo sapiens = modern humans

22. Figure 1.4 KINGDOM (Animalia) PHYLUM (Chordata) CLASS (Mammalia) ORDER
(Primates)
FAMILY
(Hominidae)
GENUS
(Homo)
SPECIES
(sapiens)
Figure 1.4

23. The Organization of Life
Living things function and interact with each other on many levels
The organization of life is a hierarchy of levels of increasing complexity
Cellular
Organismal
Ecological (populational)
The following slide sequence shows the hierarchy of transitions from one level of complexity to the next—emphasize the interconnectedness.

24. Cellular Level Molecules Organelles Cells
Atoms combine to make molecules
Organelles
Structures within cells that perform dedicated functions
Cells
Membrane-bound untis

25. Organismal Level Tissues Organs Organ systems Organism
Collection of cells that work together to perform a specialized function
Organs
Group of tissues formed together to perform specialized functions
Organ systems
group of related organs that work together
Organism
Individual living thing resulting from organ systems working together to achieve homeostasis

26. Ecological (populational) Level
Group of organisms of same species living together
Species
All populations of a specific kind of organism
Community
Populations of different organisms that interact with one another living in a particular area
Ecosystem
Created by communities that interact with each other

27. The Organization of Life
At higher levels of the living hierarchy, new properties become apparent that were absent at the lower levels
These emergent properties result from the interaction of diverse but simpler components
Many higher order processes that are hallmarks of life are emergent properties
metabolism
consciousness

28. Biological Themes The study of life is organized around general themes
5 biological themes emerge repeatedly at any hierarchical level of biological study:
Evolution
Flow of energy
Cooperation
Structure determines function
Homeostasis

29. EVOLUTION Evolution is genetic change in a species over time
The mechanism for evolution is natural selection
The diversity of life is explained by evolutionary processes

30. The Flow of Energy all living things require energy
energy from the sun flows through the living world
organisms acquire energy differently
how much energy is available determines how many and what kinds of organisms can live together in an ecosystem
Consumption
Death
Detritus
Soil nutrient pool
Decomposer
food web

31. Cooperation
As energy and other resources are limiting, many organisms have evolved cooperation as a means of survival
Symbiosis-Relationship between 2 species living in same community
Mutualism
Parasitism
Commensalism

32. Structure Determines Function
Evolution favors structures that function in an adaptive manner
Many structures are specialized for a particular function
The convergence of structure and function occurs at levels of the organizational hierarchy

33. Homeostasis Homeostasis is a physiological condition of “steady-state”
The internal environment of organisms is remarkably stable
Organisms act to control their internal environments so that the complex processes of metabolism function efficiently

34. How Scientists Think
Science is a process of investigation, using observation, experimentation, and reasoning
REMEMBER
Science is not always 100% correct
Individuals are not completely without bias
Science is limited
it is limited to organisms and processes that can be observed and measured
science cannot be relied upon to solve all problems
May mention that a Ph.D. is actually a doctorate of philosophy.

35. How Scientists Think
Deductive reasoning uses general principles to explain specific observations
It’s not a scientific approach
Top down (general to specific)
This form of reasoning is common to many disciplines, including
mathematical proofs
politics
computing

36. How Scientists Think
Inductive reasoning is the way of discovering general principles from examination of specific observations
Bottom-up (specific to general)
Scientists employ inductive reasoning by forming and testing possible explanations for specific observations
These possible explanations are called hypotheses

37. Deductive vs. Inductive Reasoning
Two boys are playing with a soccer ball
The boys use 2 different approaches to explain the result of kicking the ball into the air
Boy 1: “I've noticed that every time I kick a ball up, it comes back down, so I guess this next time when I kick it up, it will come back down too”.
Boy 2: “I know that Newton’s law of Gravity states that what goes up must come down, so if I kick a ball in the air, it must fall back down to the ground”.

38. Deductive vs. Inductive
Boy 2
Uses known theory or law to predict the result of an event
Top-down (starting big and getting small)
Boy 1
Uses observations to predict the result of an event
Bottom-up (starts small and gets big)
Many times, cases can be supported using both inductive and deductive arguments. They are not mutually exclusive!

39. Stages of a Scientific Investigation
Biology is a dynamic science with new ideas appearing and replacing old ones
Scientists systematically conduct experiments to evaluate hypotheses about observed phenomena
These experimental results can either support or refute a proposed hypothesis
They also lead to more questions and more experimentation!

40. Science in Action The scientific process has 6 steps: Observation
Hypothesis
Predictions
Testing
Controls
Conclusion

41. Stages of a Scientific Investigation
1. Observation
science begins with careful observation of natural phenomena
These observations lead to questions
2. Hypothesis
scientists make an educated guess that might be true
often scientists formulate multiple ideas about a phenomenon; these are called alternative hypotheses

42. Stages of a Scientific Investigation
3. Predictions
if a hypothesis is correct, then specific consequences can be expected
4. Testing
scientists conduct experiments to attempt to verify predictions made by hypotheses

43. Stages of a Scientific Investigation
5. Controls
experiments usually employ a parallel design
scientists use a control to assess the influence of potential factors, called variables
conditions stay the same in the control in comparison to the variable condition
6. Conclusion
a hypothesis that has been tested and not rejected is tentatively accepted
Most experiments lead to future experiments!

44. The scientific process

45. Theory and Certainty
The term “theory” means different things to different audiences
To scientists
a theory represents certainty and is a unifying explanation for a broad range of observations
Scientists’ acceptance of theory is provisional
To the general public
a theory implies a lack of knowledge or guess

46. Four Theories Unify Biology as a Science
1. The Cell Theory
2. The Gene Theory
3. The Theory of Heredity
4. The Theory of Evolution

47. The Cell Theory 1665 Cells first discovered by Robert Hooke
1839 German biologists Schleiden & Schwann put forth Cell Theory based on many observations of theirs and others
Theory States:
the cell is the most basic unit of life
all organisms are composed of at least one cell
all cells come from pre-existing cells

48. The Gene Theory
Genetic information is encoded in molecules of deoxyribonucleic acid (DNA)
Genes encode specific proteins or RNA or act to regulate other genes
The Theory States:
the proteins and RNA encoded by an organism’s genes determine what it will be like in terms of form and function

49. The Theory of Heredity
1865 Gregor Mendel’s theory of heredity gave rise to the field of genetics
The Theory States:
Genes are passed down through generations as discrete units, they do not blend together
Chromosomal theory of inheritance located Mendelian genes on chromosomes

50. The Theory of Evolution
1859 Charles Darwin
The theory of evolution explains the unity and diversity of life as “descent with modification”
All living organisms are related to one another in a common tree of descent
The Theory States
Changes in genes passed from parents to offspring result in changes in future generations of a population
Changes will thrive in population if they are adaptive
Natural selection is the major mechanism for this change