1. Themes in the Study of Life
Chapter 1
Themes in the Study of Life

2. What is Biology?

3. What is Biology? Scientific study of Life Filled with QUESTIONS
Good Questions
Questions that can be investigated

4. What is Life?

5. What is Life?
7 Properties of Life

6. What is Life? 7 Properties of Life Order Evolutionary adaptation
Responding to the environment
Growth and development
Reproduction
Energy processing
Regulation

7. What are the Major Themes of Biology

8. Major Themes of Biology
New properties emerge at each level in the biological hierarchy
Organisms interact with their environments, exchanging matter and energy
Structure and function are correlated at all levels of biological organization
Cells are an organism’s basic units of structure and functions
The continuity of life is based on heritable information in the form of DNA
Feedback mechanisms regulate biological systems

9. Evolution “Nothing makes sense except in the light of evolution” - Who Said This?

10. Evolution “Nothing makes sense except in the light of evolution” Dobzhansky

11. Evolution “Nothing makes sense except in the light of evolution” Dobzhansky
Core Theme
Evolution accounts for the unity and diversity of life
Its importance will demonstrate a large role in this course
Can always refer to Section 1.2 throughout the semester

12. How do scientists pose and answer questions about the natural world?

13. How is Biology examined?

14. How is Biology examined?
Reductionist approach
Holistic approach
Systems biology

15. How is Biology examined?
Reductionist approach

16. How is Biology examined?
Reductionist approach
Reduce complex systems to simple components

17. How is Biology examined?
Reductionist approach
Reduce complex systems to simple components
Holistic approach

18. How is Biology examined?
Reductionist approach
Reduce complex systems to simple components
Holistic approach
Larger-scale, with the objective of understanding how the emergent properties work together

19. How is Biology examined?
Reductionist approach
Reduce complex systems to simple components
Holistic approach
Larger-scale, with the objective of understanding how the emergent properties work together
Systems biology

20. How is Biology examined?
Reductionist approach
Reduce complex systems to simple components
Holistic approach
Larger-scale, with the objective of understanding how the emergent properties work together
Systems biology
Goal is to construct models for the behavior of a whole systems

21. What is inquiry?

22. What is inquiry?
Inquiry is the search for information and explanation that often focuses on specific questions

23. Scientists use two main forms of scientific inquiry
Discovery Science
Hypothesis-Based Science

24. Scientists use two main forms of scientific inquiry
Discovery Science

25. Scientists use two main forms of scientific inquiry
Discovery Science
Describing nature
More qualitative in nature
Can have quantitative aspects
Describes natural processes
Uses observation to gather information (directly or indirectly) with tools
Recorded observations are called data

26. Scientists use two main forms of scientific inquiry
Hypothesis-Based Science

27. Scientists use two main forms of scientific inquiry
Hypothesis-Based Science
Describing nature
More qualitative in nature
Can have quantitative aspects
Describes natural processes
Uses observation to gather information (directly or indirectly) with tools
Recorded observations are called data

28. What is a hypothesis?

29. What is a hypothesis? Tentative answer to a well-framed question
Explanation on trial
Educated Guess that is based on experience and the data available from Observation

30. What makes a Good Hypothesis?

31. What makes a Good Hypothesis?
Testable
Falsifiable
Cannot be PROVEN
Gains credibility by surviving attempts to falsify it

32. What makes a Good Hypothesis?
Testable

33. What makes a Good Hypothesis?
Testable
A way to check the validity

34. What makes a Good Hypothesis?
Testable
A way to check the validity
Falsifiable

35. What makes a Good Hypothesis?
Testable
A way to check the validity
Falsifiable
There must be some observation or experiment that could reveal if such an idea is NOT true
Generally, scientists frame two or more alternative hypotheses and design experiments to falsify

36. What makes a Good Hypothesis?
Testable
A way to check the validity
Falsifiable
There must be some observation or experiment that could reveal if such an idea is NOT true
Generally, scientists frame two or more alternative hypotheses and design experiments to falsify
Cannot be PROVEN

37. What makes a Good Hypothesis?
Testable
A way to check the validity
Falsifiable
There must be some observation or experiment that could reveal if such an idea is NOT true
Generally, scientists frame two or more alternative hypotheses and design experiments to falsify
Cannot be PROVEN
Testing supports a hypothesis not by Proving it, but instead by not eliminating it through the falsification
It’s impossible to test ALL alternative hypothesis

38. What makes a Good Hypothesis?
Testable
A way to check the validity
Falsifiable
There must be some observation or experiment that could reveal if such an idea is NOT true
Generally, scientists frame two or more alternative hypotheses and design experiments to falsify
Cannot be PROVEN
Testing supports a hypothesis not by Proving it, but instead by not eliminating it through the falsification
It’s impossible to test ALL alternative hypothesis
Gains credibility by surviving attempts to falsify it

39. What are the Types of Data?

40. Types of Data
Qualitative
Quantitative

41. Types of Data
Qualitative

42. Types of Data Qualitative Recorded descriptions rather than numerical
General observations
Colors

43. Types of Data Qualitative Quantitative
Recorded descriptions rather than numerical
General observations
Colors
Quantitative

44. Types of Data Qualitative Quantitative
Recorded descriptions rather than numerical
General observations
Colors
Quantitative
Recorded measurements
Numerical in nature

45. What are theTypes of Reasoning

46. Types of Reasoning
Inductive Reasoning
Deductive Reasoning

47. Types of Reasoning
Inductive Reasoning

48. Types of Reasoning Inductive Reasoning From induction
Derive generalizations from a large number of specific observations
Ex:
If every organisms that you have studied is made of cells, then it would be acceptable to induce that all organisms are made of cells.

49. Types of Reasoning Inductive Reasoning Deductive Reasoning
From induction
Derive generalizations from a large number of specific observations
Ex:
If every organisms that you have studied is made of cells, then it would be acceptable to induce that all organisms are made of cells.
Deductive Reasoning

50. Types of Reasoning Inductive Reasoning Deductive Reasoning
From induction
Derive generalizations from a large number of specific observations
Ex:
If every organisms that you have studied is made of cells, then it would be acceptable to induce that all organisms are made of cells.
Deductive Reasoning
Logic flows from general to specific
Usually take the form of prediction of experimental or observational results
If all organisms are made of cells, and humans are organisms, then humans are composed of cells

51. Scientific Method Ask a Question Do Background Research
Construct a Hypothesis
Test Your Hypothesis by Doing an Experiment
Analyze Your Data and Draw a Conclusion
Communicate Your Results

53. What is Experimental Design?

54. Integrating Experimental Design into Science

55. Experimental Design: The Process
Paper airplane - everybody builds one
Observe the plane’s flight
Ready, set, hold it …
How do we determine which is best?
5 minutes to modify, make one change
Write your hypothesis on your plane

56. Leading Questions How did you act on your plane?
What did you purposefully change about your plane?
How did you determine your plane’s response?
What remained the same about about your plane?

58. Experimental Design Diagram

59. Experimental Design Problems
Compost & Bean Plants
After studying about recycling, members of John's biology class investigated the effect of various recycled products on plant growth. John's lab group compared the effect of different aged grass compost on bean plants. Because decomposition is necessary for release of nutrients, the group hypothesized that older grass compost would produce taller bean plants Three flats of bean plants (25 plantslflat) were grown for 5 days. The plants were then fertilized as follows: (a) Flat A: 450 g of three-month-old compost, (b) Flat B: 450 g of six-month-old compost, and (c) Flat C: 0 g compost. The plants received the same amount of sunlight and water each day At the end of 30 days the group recorded the height of the plants (cm).

60. Experimental Design Diagram

61. Scenario 2 Metals & Rusting Iron
In chemistry class, Allen determined the effectiveness of various metals in releasing hydrogen gas from hydrochloric acid. Several weeks later, Allen read that a utilities company was burying lead next to iron pipes to prevent rusting Allen hypothesized that less rusting would occur with the more active metals. He placed the following into separate beakers of water: (a) 1 iron nail, (b) 1 iron nail wrapped with an aluminum strip, (c) 1 iron nail wrapped with a magnesium strip, (d) 1 iron nail wrapped with a lead strip. He used the same amount of water, equal amounts (mass) of the metals and the same type of iron nails. At the end of 5 days, he rated the amount of rusting as small, moderate, or large. He also recorded the color of the water.

62. Experimental Design Diagram

63. Perfumes & Bee's Behavior
JoAnna read that certain perfume esters would agitate bees. Because perfume formulas are secret, she decided to determine if the unknown Ester X was present in four different perfumes by observing the bees' behavior. She placed a saucer containing 10 ml of the first perfume 3 m from the hive. She recorded the time required for the bees to emerge and made observations on their behavior. After a 30-minute recovery period, she tested the second, third, and fourth perfumes. All experiments were conducted on the same day when the weather conditions were similar, e.g., air, temperature and wind.

64. Experimental Design Diagram

65. Fossils and Cliff Depth
Susan observed that different kinds and amounts of fossils were preset in a cliff behind her house. She wondered why changes in fossils content occurred from the top to the bank. She marked the bank at five positions: 5,10,15, 20, and 25m from the surface. She removed 1 bucket of soil from each of the positions and determined the kind and number of fossils in each sample.

66. Experimental Design Diagram
Title: The effect of depth on the different types and amounts of fossils.
Hypothesis: If depth increases in a fossil bank, then different fossils will occur.
Independent Variable: Depth of soil
Modifications
# of Trials
Dependent Variable: Amount and type of fossils.
Constant: 1 bucket
Control ?

67. Aloe vera and Planaria
Jackie read that Aloe vera promoted healing of burned tissue. She decided to investigate the effect of varying amounts of aloe vera and regeneration of planaria. She bisected the planaria to obtain 10 parts (5 heads and 5 tails) for each experimental group. She applied concentrations of 0%, 10%, 20%, and 30% Aloe vera to the groups. Fifteen ml of Aloe vera solutions were applied. All planaria were maintained in a growth chamber with identical food, temperature, and humidity. On day 15, Jackie observed the regeneration of the planaria parts and categorized deeloped as full, partial, or none.

68. Experimental Design Diagram
Title: The effect of aloe vera on regeneration of planaria.
Hypothesis: If more aloe vera is used then there will be an increased amount of aloe vera.
Independent Variable: Percentage of Aloe Vera
Modifications 10% 20% 30%
# of Trials
Dependent Variable: amount of regeneration
Constant: food, temperature, humidity
Control : 0% aloe vera