1. Introduction to Science and Exploring Life
Chapter 1:
Introduction to Science and Exploring Life *

2. Early Views of life
spontaneous generation/biogenesis *

3. The Redi Experiment
Idea was challenged by scientist Francesco Redi in 1698.
Designed an experiment where 3 jars contained meat.
It was implied that flies were the source of the maggots which lead to the theory of Biogenesis (life from preexisting life) *

4. PROPERTIES of LIFE -Made of Cells.
-The Cell is the basic unit of life-is self contained and possesses a barrier (membrane) which separates itself from the environment.
-The cell is the lowest level of organization that can perform all activities required for life
-Two types of organisms.
Unicellular - One celled organism (Uni=1)
Multicellular - Many cells (Multi=”many”) *

5. PROPERTIES of LIFE Living Things must Reproduce.
-Must be able to create more of it’s own kind
Two types of reproduction:
Sexual - Two parent organisms combine genetic material to produce the offspring.
Asexual - When a single organism can divide or “bud” to create it’s offspring without another of it’s species. *

6. PROPERTIES of LIFE Living things have genetic material
Instructions for making all the bodies proteins
Located in the nucleus (eukaryotes) or nucleiod region (prokaryotes)
DNA is inherited by offspring from their parents
DNA controls the development and maintenance of organisms *

7. PROPERTIES of LIFE Living things must Grow & Develop.
Growth refers to two processes.
-Increase in the number and size of cells.
Development refers to changes in the organism which occur through it’s life-span, inc. cell differentiation, aging, organ development *

8. PROPERTIES of LIFE Living things obtain & use energy.
Energy is used by all living things for growth, development & reproduction. *

9. PROPERTIES of LIFE
-Living things must Respond (or react) to their environment in some way.
-Something which causes an organism to react is known as a Stimulus (stimuli).
-Most responses are geared for maintaining Homeostasis.
Homeostasis is a process where an organism maintains a stable internal environment so life can continue.
Some examples include temperature, pH, and water content of the cell. *

10. Feedback Regulation: Negative
Accumulation of an end product of a process slows that process *

11. Feedback Regulation: Positive
An end product speeds up its production *

12. Hierarchy of Organization
Biosphere
9 Organelles
8 Cells
Molecules
Ecosystems
Communities
7 Tissues
Atoms
Populations
6 Organs and organ systems
Organisms *

13. Unifying Themes in Biology
Evolution~ biology’s core theme; differential reproductive success
Emergent Properties~ hierarchy of life, sum is greater than each part
The Cell~ all organism’s basic structure
Heritable Information~ DNA
Structure & Function~ form and function
Environmental Interaction~ organisms are open systems
Regulation~ feedback mechanisms
Unity & Diversity~ universal genetic code
Scientific Inquiry~ observation; testing; repeatability
Science, Technology & Society~ functions of our world *

14. Nature of Science
1) Science has principles- explain the natural world, gather evidence, science is a process
2) Characteristics of Science- conclusions are reliable (tentative), non dogmatic, provides evidence only
3)Science exists in a cultural context- human endeavor, science corrects itself

15. Science Discovery
• Inductive Reasoning- "bottom up" approach move from a set of specific observations to general conclusions EX: Cells are observed in organisms x, y, and z, therefore all animals have cells. (Cell Theory) •
Deductive Reasoning- "top-down" approach flows from general to specific EX: If all organisms have cells and humans are organisms, then humans should have cells

16. Good Experimental Design
Hypothesis based off observation
Independent & dependent variables
Control group/experimental group/ constants
Random sampling/Large sample size (n)
Repeated – multiple trials (3)
Graphs/Data Table/Calculations
Analyze results (statistically)/Conclusions/
Describe expected outcomes
NOTE: Can’t ignore or rule out data which do not support the hypothesis

17. Variables
-independent variable is the one that is changed by the scientist.
-dependent variable is observed to see how it responds to the change made to the independent variable. What’s being measured.
-controlled variables (constants) versus control group

18. Hypothesis-Based Science
-Inquiry that asks specific questions
-Usually involves the proposing and testing of hypothetical explanations, or hypotheses
-Hypothesis is a tentative answer to a well-framed question, an explanation on trial
-Makes predictions that can be tested
-Usually expressed as an: If…., then …. Statement

19. How to write a hypothesis
Writing A Hypothesis
a question,
"Does temperature affect
fermentation?"
a conditional statement,
"Temperature may affect
fermentation."
an “If, then” statement,
"If fermentation rate is related
to temperature, then increasing
the temperature will increase
gas production.
an “as” statement,
“As temperature increases,
as production through
fermentation will also increase
The format of a hypothesis includes the independent and dependent
variable (what is to be manipulated and what is to be observed).

20. Data Collection- recorded observations
Quantitative- analysis of numerical data (measure, count, etc)
Qualitative- analysis of data such as words (e.g., from interviews), pictures (e.g., video), or objects (e.g., an artifact).

21. Graphing -Title - Units Labeled - IV (X) and DV (Y)
- Proportional Increments
- Points plotted
- Label if more than one line

22. Line versus Bar Graph Line Graph- Change over time
Bar Graph/Histagram-
Comparing Data Sets

23. Extrapolation
Analysis of data is used to make predictions

24. Comparisons -Explanation to specific question -Prediction
Hypothesis
-Explanation to specific question
-Prediction
-Educated guess
-Tested by experiment or continued observation
-Can be disproven, but not can’t proven to be true
Theory
-Summarizes group of hypothesis supported by repeated testing
-Broader in scope
-New hypotheses can be generated from it
-Supported by massive body of evidence
-Ex. Big Bang Theory
Scientific Law
-Statement of fact
-Explains things, but doesn’t describe them
-Generally accepted to be true and universal
-Basis for scientific method
-Ex. Law of Planetary Motion