1. CHAPTER 1 The Nature of Science and the Characteristics of Life

2. This Class is about You…
This class is about us and how we connect with other living beings and our surroundings
Many controversies facing society today require an understanding of science to make informed decisions
What are some examples of these controversies?

3. What is Biology? Biology is the scientific study of life
What does Bio mean?
What does –ology mean?

4. The Language of Science
Challenging vocabulary: heck no!
Most scientific vocabulary are “little words”, or roots, that are linked together
If you learn the meanings of these roots, you'll find scientific vocabulary much easier to understand!

5. The Language of Science these words will not be on the test
What is hydrology? What is a cytoskeleton? What is hyperthyroid? What is abiotic? What is hypodermic?
Learning roots will help in EVERY part of your college career! Take this time in BI101 to familiarize yourself with roots!

6. The Nature of Science
Humans have a natural spirit of inquiry, driving science
We start this as babies, this is how we learned many things!
Both types of inquiry are important! Discover through both experience and study.

7. The Nature of Science
Scientific thinking is objective and values evidence
W2L: What does it mean to be objective?
W2L: What kinds of things can be judged objectively? What about subjectively?

8. The Nature of Science Science: is a body of knowledge
is an evidence-based process for acquiring knowledge
deals with the natural world
is based on evidence that can be demonstrated through observation and/or experiments

9. The Nature of Science
The process that generates scientific knowledge is called the scientific method
The scientific method is used in all areas of science

10. Figure 1.2 Scientific Hypotheses Must be Testable

11. An Example of the Scientific Method
You have observed that some fish swim slower than others.

12. The Nature of Science: Observations
The process of science begins with an observation of the natural world
An observation is a description, measurement, or record of any object or phenomenon
An observation must be reproducible

13. An Example of the Scientific Method
You develop a hypothesis that states: the faster a fish swims, the larger gill area is relative to body size.
--Does this hypothesis make sense?

14. The Nature of Science: Hypotheses
A scientific hypothesis is an informed, logical, and plausible explanation about the natural world
Must be testable!

15. An Example of the Scientific Method
You predict that: If a fish swims faster than another fish then the faster fish will have a larger gill area relative to its body size when compared to the slower fish.

16. The Nature of Science: Predictions
Using the hypothesis make a prediction in an “if-then” statement
Does not have to be an “if-then” statement but it is easier to write this way.

17. An Example of the Scientific Method
You test your hypothesis by measuring the following on many types of fish:
Gill area
Body size
W2L: Why test many types of fish?

18. The Nature of Science: Test Using Good Experimental Design
An experiment is a repeatable manipulation of one or more aspect of the natural world by experimenters
In a well designed experiment:
only one independent variable is manipulated at a time
The experiment is controlled

19. The Nature of Science: Independent vs. Dependent Variable
The dependent variable is effected by the independent variable.
Remember only one independent variable is manipulated at a time
What would happen if we tested two?

20. The Nature of Science: Independent vs. Dependent Variable
In this experiment which
is the independent and
dependent variable?
Hint: “I” determine the
independent variable
as the researcher.
In an experiment, only one
independent variable is
manipulated at a time. Why?

21. The Nature of Science: Independent vs. Dependent Variable
W2L: Let’s graph this!
Which variable is on the x-axis?
Which variable is on the y-axis?

22. The Nature of Science: Controlled Experiment
A controlled experiment:
Comparable in all respects except one or more group(s) are exposed to systemic change and one is not
Control group:
No change in independent variable
Treatment group:
Independent variable is manipulated by the researcher

23. An Example of the Scientific Method
What were your results?
Is your hypothesis supported or not?

24. An Example of the Scientific Method
Now you have another observation that you can base another hypothesis on.

25. An Example of the Scientific Method1*
What if the data doesn’t support the hypothesis?
This is when science gets even more fun!! Sometimes 9* 18
30*
50*
*this data has been changed and does not reflect what actually occurs in nature

26. The Nature of Science: Scientific Theory
A scientific theory is a body of knowledge that has stood the test of time
A hypothesis becomes a scientific theory:
After it has been repeatedly confirmed through diverse methods of testing
When it is accepted by experts as the best explanation of the truth about the phenomenon
A scientific fact is a direct and repeatable observation about the natural world

27. Just a theory?
When we use the word "theory" in everyday life, we usually mean an idea or a guess, but the word has a much different meaning in science…
Some theories in Biology:
Cell Theory
Theory of Natural Selection
Germ Theory

28. Characteristics of Living Organisms
All living organisms share a set of common characteristics
Living organisms:
Are composed of one or more cells
Reproduce using deoxyribonucleic acid (DNA)
Obtain energy from their environment to support metabolism
Sense and respond to their environment
Maintain homeostasis
Are capable of evolving as a group

29. Characteristics of Living Organisms: Cells
Basic unit of life
Cells enclosed by a water-repellent layer called the plasma membrane

30. Characteristics of Living Organisms: Reproduce via DNA
DNA is genetic material that contains all the instructions for building new organisms
Passes information from parent to offspring

31. Characteristics of Living Organisms: Energy from the Environment
All organisms need energy to live, they get this energy from their environment.
Plants are producers:
convert energy from the sun into chemical energy
Consumers use energy from other consumers or directly from producers
Ex: cat eats mouse and gets some of the energy that the mouse contained

32. Characteristics of Living Organisms: Homeostasis
Keeping the balance
Organisms sense and respond to their environment in order to maintain constant internal conditions through a process called homeostasis

33. Characteristics of Living Organisms: Groups Evolving
Evolution allows an organism to survive and reproduce better than competing organisms

34. In biology there is a hierarchy in order from less to more complex.