1. BIOLOGY!
The Study of Life
bios = life
ology = study of

2. What is LIFE? I know it when I see it!
What are some characteristics we associate with the “definition” life?

3. What are the Properties of Life?
Precise organization (order)
Homeostasis
Response to the environment
Energy uptake and use
Growth and development
Reproduction
Ability to Evolve

4. Properties of Life
1) Order

5. Properties of Life
2) Homeostasis

6. Properties of Life
3) Response to the Environment

7. Properties of Life
4) Energy Processing

8. Properties of Life
5) Growth and Development

9. Properties of Life
6) Reproduction

10. Properties of Life
7) Evolution & Adaptation

11. Properties of Life? Precise organization (order) Homeostasis
Response to the environment
Energy uptake and use
Growth and development
Reproduction
Ability to Evolve

12. Is It Alive? Why or Why Not?
Cologne Cathedral
Baby Chicken
Escherichia coli bacteria
Hoover Dam

13. Levels of Organization:
Biosphere
Ecosystems
Communities
Organs or Organ Systems
Populations
Individuals

14. Levels of Organization:
Organs or Organ Systems
Tissues
Cells
Organelles
Molecules

15. Emergent Properties
Each level of the biological hierarchy is more than merely the sum of its parts
Emergent properties result from interactions among components at each level

16. Emergent Properties.
Life itself is an emergent property

17. Cells are the simplest units of life.
The cell is the lowest level of structure that has all of the properties or qualities we use to define life.
Some organisms consist of a single cell, others are multicellular aggregates of specialized cells.

18. “Observation XVIII" of the Micrographia
The first cells were observed and named by Robert Hooke in 1665 from a slice of cork.
Hooke’s Compound Microscope
“Observation XVIII" of the Micrographia

19. Van Leewenhoek`s simple microscope
Anton van Leeuwenhoek, was the first to see single-celled organisms in pond water and observe cells in blood and sperm.
Anton van Leewenhoek
“No more pleasant site has met my eye than this!”
Van Leewenhoek`s simple microscope

20. Leeuwenhoek reported how in the plaque scraped from his teeth: "I then most always saw, with great wonder, that in the said matter there were many very little living animalcules, very prettily a-moving. The biggest sort. . . had a very strong and swift motion, and shot through the spittle like a pike does through the water."
In the mouth an old man who had reportedly never cleaned his teeth in his life: "an unbelievably great company of living animalcules, a-swimming more nimbly than any I had ever seen up to this time.”

21. THE CELL THEORY In 1855, Rudolf Virchow extended the cell theory :
In 1839, Matthais Schleiden and Theodor Schwann extrapolated from their own microscopic research and that of others to propose the cell theory.
The cell theory postulates that cells are the basic unit of structure and physiology in all living things.
One of the great paradigms of Biology…
Cell Theory is to Biology as the Atomic Theory is to Physics
But... Thought cells formed spontaneously… in a manner similar to crystal growth
In 1855, Rudolf Virchow extended the cell theory :
New cells are produced by the division of existing cells.
Critical process in reproduction, growth, and repair of multicellular organisms.

22. All cells are enclosed by a membrane that regulates the passage of materials between the cell and its surroundings.
All cells contain DNA, the heritable material that directs the cell’s activities.
Two major kinds of cells - prokaryotic cells and eukaryotic cells - can be distinguished by their structural organization.
The cells of the microorganisms called bacteria and archaea are prokaryotic. Do not contain organelles.
All other forms of life have the more complex eukaryotic cells.

23. The continuity of life is based on heritable information in the form of DNA
Biological instructions for life are encoded in DNA (deoxyribonucleic acid).
DNA is the substance of genes.

24. Genomes (Human and Others)
The entire “library” of genetic instructions that an organism inherits is called its genome.
The genome of a human cell is 3 billion chemical letters long.
The “rough draft” of the sequence of nucleotides in the human genome was published in 2001.
Biologists are learning the functions of thousands of genes and how their activities are coordinated in the development of an organism.

25. Unity & Diversity Diversity: 1.5 million species described
third million plant species
vertebrates
almost 1 million insects
Estimates 5-30 million species (10% described?)
Diversity decreasing as species go extinct.

26. Unity & Diversity
Taxonomy: classifying and organizing life

27. 7) Unity & Diversity Taxonomy: classifying and organizing life species
Genus
Family
Order
Class
Phylum
Kingdom
Spaghetti
Good
For
Over
Came
Phillip
King

28. Examples from the Animal Kingdom
GROUP NAME
ORGANISM
HUMAN
CHIMPANZEE
HOUSE CAT
LION
HOUSEFLY
KINGDOM
Animalia
PHYLUM
Chordate
Arthropoda
CLASS
Mammal
Insect
ORDER
Primates
Carnivora
Diptera
FAMILY
Hominidae
Pongidae
Felidae
Muscidae
GENUS
Homo
Pan
Felis
Panthera
Musca
SPECIES
sapiens
troglodytes
domestica
leo
Scientific Name
Homo sapiens
Pan troglodytes
Felis domestica
Felis leo
Musca domestica

29. = Monera Unity & Diversity DOMAINS Bacteria Archea Eukarya Plantae
Animalia
Fungi
Protista
= Monera

30. Unity & Diversity 5 Kingdoms Monera = Bacteria Plantae = Plants
Animalia = Animals
Fungi = Fungi
Protista = Protists

31. Unity & Diversity Unity within diversity:
DNA as the common information molecule
Eukaryotes all share common cellular architecture

32. The Nature of Science (& “the” scientific method)
“Science is a process of inquiry that includes repeatable observations and testable hypotheses.”
A) Discovery Science (Induction)
Observations
Data collection
In field or lab!
B) Hypothetico-deductive model
Scientific method
Formal process
Experimentation
In field or lab!

33. Puzzling observation → Causal question
“How weird!... some of the frogs in this pond have 3 back legs! What the heck is going on here!?!?”
Puzzling observation → Causal question

34. “What causes frog deformities?”
Causal Questions: Ask what is CAUSING a particular phenomenon or observation.
“What causes frog deformities?”
CAUSATION
is very different from
CORRELATION

35. Causal question: “What is causing these frog deformities?”
Possible explanations (hypotheses):
Polluted water (e.g. herbicide runoff from fields)
Infection by parasites
Increased UV radiation
CAUSATION does not equal CORRELATION
Not all explanations are hypotheses
Elves cast a spell on the frogs.
God made them that way.

36. A possible explanation about what CAUSES something is a: HYPOTHESIS!
Pollution is causes leg deformities in leopard frogs.
Prediction:
IF frog deformities are caused by polluted water,
THEN there should be more deformities in frogs raised experimentally in polluted water vs. those experimentally raised in clean water.

37. IF the hypothesis is TRUE, THEN we can predict an outcome.
Predicted Outcome from a planned experiment
Compare!
Test Data:
% deformed frogs in atrazine water = 0
% deformed frogs in pure water= 0
Actual Experiment

38. Causal Question: Question about how or why things occur.
Hypothesis: A testable explanation, a possible answer to a causal question
Prediction: An expectation (derived from the hypothesis) about what you SHOULD see, if you were to do an experiment or make more observations.
Test: Evidence (data) derived from an actual experiment or observation that can be matched against predicted result.
Conclusion: A decision about whether or not the evidence supports the hypothesis.

39. Science is a Cycle: Hypothesis Conclusion Prediction Test (data)
Causal Question
Hypothesis
Conclusion
Prediction
Test (data)

40. Label each statement: Causal question, hypothesis, prediction, test/data, and conclusion.
Trematode infection is probably responsible for frog deformities
What makes tadpoles produce frogs with extra legs?
The proportion of adult frogs with deformities should increase with increasing exposure to parasitic infections
I wonder if infection by trematodes could disrupt tadpole development?
Conclusion
Causal Question
Prediction
Hypothesis
Test
Density of trematodes (per tad)
% of frogs w/ limb deformities 16 70 32 90 48
100

41. New Hypothesis: Abnormal development of frogs is caused by a trematode parasite

42. Steps of the Scientific Method
Observation
The flashlight doesn’t work!
Ask Questions (Collect Information)
(a) Why doesn’t the flashlight work?
(b) How does a flashlight work?
Form a hypothesis (Educated Guess)
The batteries are dead!
Experimentation:Test of hypothesis
Replace the batteries.
Collect results & Draw a conclusion
(a) It works – hypothesis supported
(b) It doesn’t work – hypothesis rejected
(go to step 3)

43. A Case Study in Scientific Inquiry: Investigating Mimicry in Snake Populations
In mimicry
A harmless species resembles a harmful species

44. Field Experiments with Mimicry….
In this 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 coralsnakes are present
Key
Kingsnake
Coralsnake
North Carolina
South Carolina
Eastern Coral snakes are lethal to most predators… so….

45. Field Experiments with Artificial Snakes
To test the mimicry hypothesis
Researchers made hundreds of artificial snakes, an
experimental group: resembled king snakes
control group: of plain brown snakes
(a) Artificial king snake
(b) Brown artificial snake that has been attacked

46. % attacks on “kingsnakes” % of attacks on brown “snakes”
After four weeks the researchers collected the model snakes… (the data!)
Key
% attacks on “kingsnakes”
% of attacks on brown “snakes”
Field sites
Coralsnakes present: most attacks on brown models
17%
83% X
84%
16%
Coralsnakes absent: most attacks on kingsnake models
And in this case the data on incidence of predation fit a key prediction…..

47. Limitations of the Scientific Method
Remember:
Science seeks natural causes for natural phenomena.
The scope of science is limited to the study of structures and processes that we can observe and measure, either directly or indirectly.
Verifiable observations and measurements are part of science.
Results are repeatable. (Scientists publish their findings, so other scientists can verify them)

48. EVOLUTION…
Came into sharp focus in 1859 when Charles Darwin published On the Origin of Species by Natural Selection

49. Darwin proposed natural selection
As the mechanism for evolutionary adaptation of populations to their environments
Population
of organisms
Hereditary
variations
Differences in reproductive success
Evolution of adaptations
in the population
Overproduction
and struggle for
existence

50. Natural selection- is one of the mechanisms by which evolution occurs…
1 Populations with varied inherited traits
2 Elimination of individuals with certain traits.
3 Reproduction of survivors.
4 Increasing frequency of traits that enhance survival and reproductive success.
Natural selection-
is one of the mechanisms by which evolution occurs…
When a population’s heritable variations are exposed to environmental factors that favor the reproductive success of some individuals over others