1. Introduction to Biology
The Study of Life

2. What is science?
Science is an organized way of gathering and analyzing evidence about the world.
There are universal laws that apply to all objects in the universe, small or large, living or nonliving.

3. The goal of science is to
Provide explanations for events in
nature
To understand patterns
To make useful predictions

4. Science never stands still. New discoveries
raise new questions.
Science aims for the best understanding that current methods can reveal.

5. Science begins with making observations which involve noticing and describing events.
Scientists use the information they gather to make inferences. These are logical interpretations based on prior knowledge.

6. Scientific Method A logical method for approaching a problem
Ask a question
Form a hypothesis
Test the hypothesis
Analyze the results
Form conclusions

7. Experiment Process of testing a hypothesis
Control variable: variable that remains constant
Independent variable: variable that is changed
Dependent variable: variable that is observed
The information we gather is called data
Observation: what you actually observe
Qualitative: qualities (color, smell)
Quantitative: measurable (numbers: 3 meters)
Inference: conclusion based on an observation

8. The control group is carried out under normal conditions
The experimental group is done the same as the control group except for the dependent variable

9. Observation vs Inference
Look at these two sets of animal tracks.
Make 3 observations and 1 inference.

10. Hum…make 3 more observations and 1 inference.

11. NOW what do you think?

12. Graphing Rules Always include a title which describes your graph.
Independent variable is known or predetermined.
It is placed on the bottom of the graph.
Dependent variable is the unknown. It is placed on the side of the graph.
Label both the x and y axis. Make sure to include units.
Use an appropriate scale.

13. An understanding of science is important in making intelligent decisions about life.
Science can make recommendations but
society makes the final decisions.

14. Metric System Most experiments include measurements (quantitative).
Experiments must be able to be repeated so scientists use a common measuring system called the metric system.

15. Basic units of measuring: mass-grams

16. Length-meter

17. Volume-liter

18. Temperature-Celsius

19. Prefixes for units Milli = .001 Centi = .01 Deci = .1 1 Deka = 10
Hecto = 100
Kilo =

20. Rules to change from one to another
When you go up you multiply by 10 and move the decimal to the right.
When you go down you divide by 10 and move the decimal to the left.

21. Characteristics of Living Things
Made up of cells
Able to reproduce
Based on the genetic code-DNA
Grow and develop
Obtain and use energy (Metabolism)
Respond to their environment
Maintain a stable environment (homeostasis)
Groups of living things change over time (evolve)