1. Introduction Ch. 1

2. Points to ponder What is biology? What characterizes life?
How do we classify life?
Where do humans fit into the big picture?
How do we study science?
Where is scientific information published and what should you be aware of?

3. Biology is the Study of Life

4. Life’s Underlying Unity

5. The Search for Life
Are We Alone?

6. Enceladus one of Saturn’s Moons
See separate FlexArt PowerPoint slides for all figures and tables pre-inserted into PowerPoint without notes 6

7. Europa orbits Jupiter

8. What’s so special about these moons?
They both have water in large amounts

9. Titan: one of Saturn’s moons

10. Life’s Underlying Unity
What are the basic characteristics that define life?
What evidence would you look for on one of these moons that would tell you that life may have existed on them in the past?
What does it tell us if we discover life on one of these moons and it has characteristics similar to those of life on Earth? What if it is very different?

11. Characteristics of Life

12. What characteristics are shared by living organisms?
Life is highly organized and made of cells
Reproduce and grow
Use materials and energy from the environment
Respond to internal and external stimuli
Maintain a relatively constant internal environment (homeostasis)
Evolve

13. Composed of cells First organisms were single cells Basic unit of life
Self-contained units
Bacteria are single cells
Multicellular organisms made of different specialized cells

14. Highly Organized Complex function
Humans have tissues and organ systems
Organization is required for function

15. How are living things organized?
nervous system
shoot system
leaf
photosynthetic tissue
plant cell
brain
nervous tissue
neuron
Biosphere
Regions of the Earth’s crust,
waters, and atmosphere inhabited
by living things
Ecosystem
A community plus the physical environment
Community
Interacting populations in a particular area
Population
Organisms of the same species
in a particular area
Organism
An individual; complex individuals
contain organ systems
Organ System
Composed of several organs
working together
Organ
Composed of tissues functioning
together for a specific task
Tissue
A group of cells with a common
structure and function
Cell
The structural and functional
unit of all living things
Molecule
Union of two or more atoms
of the same or different elements
Atom
Smallest unit of an element composed of
electrons, protons, and neutrons
Figure 1.2 Levels of biological organization.

16. Lower Level of Biological Hierarchy
Atoms
Molecules
DNA and proteins
Cells
Many different types in higher organisms
Tissues
Made up of many cells
Organs
Heart and brains

17. Mid-level of Biological Hierarchy
Organ systems
Heart and blood vessels
Work together to pump blood
Individual organism
Organ systems functioning together
Each system supporting other systems
Population
Group of similar organisms
All mice living in one field

18. Top Level of Biological Hierarchy
Community
Groups of different species or organisms
Live and interact in a certain area
Ecosystems
Communities and their physical environment
Biomes
Large regions defined by distinctive characteristics
Biosphere

19. Importance of Biological Hierarchy
Molecular level to biosphere level
Intricate interactions that affect all living things including us.
Understanding the hierarchy helps us to understand the interactions.

20. What characteristics are shared by living organisms?
Life is highly organized and made of cells
Reproduce and grow
Use materials and energy from the environment
Respond to internal and external stimuli
Maintain a relatively constant internal environment (homeostasis)
Evolve

21. Reproduction via DNA
Living organisms reproduce or replicate themselves
Single-cell organisms
Produce two genetically identical cells
Multicellular organisms
Variety of ways
Seeds, eggs and sperm, etc.
Genetic material
Passed from parents to offspring
DNA: deoxyribonucleic acid

22. Growth and Development
DNA as a blueprint
Organisms grow and propagate themselves
Organisms develop and grow in complexity

23. What characteristics are shared by living organisms?
Life is highly organized and made of cells
Reproduce and grow
Use materials and energy from the environment
Respond to internal and external stimuli
Maintain a relatively constant internal environment (homeostasis)
Evolve

24. Capturing Energy Collect energy from their environment
Use energy to grow and develop
Some use the energy of sunlight
Plants capture sun’s energy via photosynthesis
Convert solar energy to chemical energy in sugars
Some use energy from other living organisms
Animals consume plants or animals

25. The sun is the ultimate source of energy on Earth
DB08010.jpg

26. What characteristics are shared by living organisms?
Life is highly organized and made of cells
Reproduce and grow
Use materials and energy from the environment
Respond to internal and external stimuli
Maintain a relatively constant internal environment (homeostasis)
Evolve

27. Sense and Response Detect danger Many organisms have multiple senses
Smell, hear, taste, touch, and see
Some senses different than human
Ultraviolet and infrared light
Electrical and ultrasonic fields
Some bacteria use magnetic particles to sense direction

28. What characteristics are shared by living organisms?
Life is highly organized and made of cells
Reproduce and grow
Use materials and energy from the environment
Respond to internal and external stimuli
Maintain a relatively constant internal environment (homeostasis)
Evolve

29. Homeostasis
All organisms engage in maintaining homeostasis in some fashion.

30. What characteristics are shared by living organisms?
Life is highly organized and made of cells
Reproduce and grow
Use materials and energy from the environment
Respond to internal and external stimuli
Maintain a relatively constant internal environment (homeostasis)
Evolve

31. All organisms Evolve!

32. Life’s Underlying Unity
What are the basic characteristics that define life?
What evidence would you look for on one of these moons that would tell you that life may have existed on them in the past?
What does it tell us if we discover life on one of these moons and it has characteristics similar to those of life on Earth? What if it is very different?

33. Life’s Underlying Unity
Fossilized Bacteria from Mars rock? NO!

35. Life’s Underlying Unity
What are the basic characteristics that define life?
What evidence would you look for on one of these moons that would tell you that life may have existed on them in the past?
What does it tell us if we discover life on one of these moons and it has characteristics similar to those of life on Earth? What if it is very different?

36. Deep Sea Hydrothermal Vent Communities

40. Adaptation to Environmental Conditions

41. Human Evolutionary History

42. Three Domains of Life

43. Classification of Life

44. How do we classify humans?
Human House cat
Domain Eukarya Eukarya
Kingdom Animalia Animalia
Phylum Chordata Chordata
Class Mammalia Mammalia
Order Primates Carnivora
Family Hominidae Felidae
Genus Homo Felis
Species sapiens domesticus

45. What distinguishes humans from other animals?
Cultural heritage or patterns of our behavior passed from one generation to the next – also seen in monkeys and some birds
Highly developed brains
Completely upright stance
Creative language skills
Varied tool use – many animals use tools including monkeys and birds among others!
Modification of our environment for our own purpose which may threaten the biosphere – other animals can engineer their habitat ex. beaver

46. Humans Negatively Impact Natural Systems

47. Process Way of knowing Natural World Statistics Scientific Method
Objective
Statistics
Conclusions Change
Process
Scientific Method
Laws, Theories

48. Scientific theories in biology

49. Germ Theory of Disease: Koch’s Postulates
The suspected pathogen (virus or bacterium) must be present in every case of the disease;
The pathogen must be isolated from the host and grown in a lab dish;
The disease must be reproduced when a pure culture of the pathogen is inoculated into a healthy susceptible host; and
The same pathogen must be recovered again from the experimentally infected host.

50. Scientific Method

52. Scientific Method Example Dr
Scientific Method Example Dr. Barry Marshall discovers the cause of stomach ulcers

54. H. Pylori and ulcers Experimented on animals – Conclusion not accepted
1985, Marshall decided to perform the experiment on himself!
He and another volunteer swallowed solution of H. pylori. 
Within the week, they felt sick and were vomiting up their stomach contents.
Examination by endoscopy showed that their stomachs were now inflamed, and biopsies of the stomach lining contained the suspected bacterium.

55. A controlled study Variables Groups
Experimental variable is the variable that is purposely changed or manipulated.
All other variables need to remain constant.
Groups
Test group is a group of subjects that are exposed to the experimental variable.
Control group is a group for comparison that is not exposed to the experimental variable.

56. How the cause of ulcers was discovered: The scientific method in action
Observations: Many patients had a particular bacterium near their ulcers.
Hypothesis: Helicobacter pylori is the cause of gastritis and ulcers.

57. How the cause of ulcers was discovered: The scientific method in action (Koch’s Postulates)
Experiment/observations:
1st – H. pylori was isolated and grown from ulcer patients.
2nd – Humans swallowing a H. pylori solution developed inflammation in their stomachs.
Conclusion: H. pylori was the cause of most ulcers and can be cured by antibiotics.

58. A controlled study in action
Figure 1.9 A controlled laboratory experiment to test the effectiveness of a medication in humans.

59. Reading about scientific information
Scientific journals are considered the best source of information but can be difficult for the lay person to understand.
Often the lay person reads secondary sources and must be wary of information taken out of context.
Be careful of information on the Internet by using reliable sources such as URLs with .edu, .gov and .org.

60. What should you look for when you read about science?
Beware of anecdotal data.
Understand methodology and results.
Does the data justify the conclusions inferred by the scientists?
Be able to read a graph.
Have some understanding of statistics.

61. Reading a graph What information does this line graph convey?
Figure The presentation of scientific data.

62. Statistical Significance
When scientists conduct an experiment, there is always the possibility that the results are due to chance or to some factor other than the experimental variable.
Investigators take into account several factors when they calculate the probability value (p) that their results were due to chance alone.
If the probability value is low, researchers describe the results as statistically significant.
A probability value of less than 5% (usually written as p < 0.05) is acceptable, but p values of <0.001 are common in many studies.

63. Does science have social responsibilities?
Science is a way of acquiring knowledge about the natural world.
It is a slightly different endeavor than technology.
Collection of data is non-judgemental
Bioethicists argue about the social issues

64. Does science have social responsibilities?
Technology is the application of scientific knowledge to human interests.
Bioethics is the branch of ethics concerned with the development and consequences of biological technology.
Genetic engineering (genetically modified crops)
Threat to biodiversity

65. Human Influence on Ecosystems
Humans tend to modify ecosystems for their own purposes.
Changes in human behavior and use of new technology can result in new diseases (emerging diseases).
Human activities may attribute to climate change (global warming).

66. Biologists work in many environments