1. Biology, 9th ed,Sylvia Mader
Chapter 01
Chapter 01
A View of Life
A View of Life

2. Biology, 9th ed,Sylvia Mader
Outline
Chapter 01
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

3. Living things vs. nonliving objects:
Defining Life (1)
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

4. Defining Life

5. Emergent Properties – Biological organization
Defining Life (2)
Emergent Properties – Biological organization
Levels range from extreme micro to global
Each level up:
More complex than preceding level
Properties:
A superset of preceding level’s properties
Emerge from interactions between components

6. Levels of Biological Organization

7. Living Things: Acquire & Process Food
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

8. Acquiring Nutrients

9. Living Things: Respond to Stimuli
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

10. Living Things: Reproduce and Develop
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

11. Rockhopper Penguins & Offspring

12. Living Things: Adapt to Change
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

13. Organization of the Biosphere
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

14. Terrestrial Ecosystems: A Grassland

15. Marine Ecosystems: A Coral Reef

16. Human Populations 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

17. Biodiversity Biodiversity: Extinction:
The total number of species (est. 15 million)
The variability of their genes, and
The ecosystems in which they live
Extinction:
The death of the last member of a species
Estimates of 400 species/day lost worldwide

18. Classification 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

19. Levels of Classification
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

20. Domains Bacteria Archaea Eukarya Microscopic unicellular prokaryotes
Bacteria-like unicellular prokaryotes
Extreme aquatic environments
Eukarya
Eukaryotes – Familiar organisms

21. Domains: The Archaea

22. Domains: The Bacteria

23. Archaea – Kingdoms still being worked out
Bacteria - Kingdoms still being worked out
Eukarya
Kingdom Protista
Kingdom Fungi
Kingdom Plantae
Kingdom Animalia

24. Domains: The Eukaryote Kindoms

25. Binomial nomenclature (two-word names) Universal Latin-based
Scientific Names
Binomial nomenclature (two-word names)
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

26. The Scientific Method: Observation and Hypothesis
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

27. The Scientific Method: A Flow Diagram

28. The Scientific Method: 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

29. The Scientific Method: 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

30. The Scientific Method: Conclusion and Review
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

31. Scientific Principle / Law:
Scientific Theory
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

32. Controlled Experiments: The Variables
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

33. Controlled Experiments: Observation & Hypotheses
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

34. Root Nodules

35. Controlled Experiments: 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

36. Crop Rotation Study

37. Controlled Experiments: Results
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

38. Controlled Experiments: Conclusion & Revision
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

39. Controlled Experiments: Revised Results & Conclusion
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

40. A Field Study

41. Biology, 9th ed,Sylvia Mader
Review
Chapter 01
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

42. Biology, 9th ed,Sylvia Mader
Chapter 01
Ending Slide Chapter 01
A View of Life
A View of Life