1. Biology and You

2. Biology
Science – an organized way of gathering and analyzing evidence about the natural world.
Examples:
Biology –
Goals of science:
Provide natural explanations for events in the natural world
Use explanations to understand patterns in nature and make predictions about natural events.

3. 5 steps of the Scientific Method
Observing and asking questions
Inferring and forming a hypothesis
Designing and carrying out a controlled experiment
Collecting and analyzing data
Drawing conclusions

4. Scientific method Observing and asking questions
Observation: act of noticing and describing events or processes in a careful, orderly way.
Inferring and forming a hypothesis
Inference: logical interpretation based on what scientists already know
Hypothesis: scientific explanation for a set of observations that can be tested in ways that support it or reject it.

5. Designing controlled experiments
Controlled experiment: one in which only one variable is changed at a time. All other variables are controlled.
Ex. Changing the liquid (water, soda and OJ) used to water plants but the amount of sunlight is the same.
Control group: exposed to same conditions as experimental groups except for one independent variable.

6. Variables Independent variable: variable that is deliberately changed
Dependent variable: variable that is observed and that changes in response to the independent variable
Example on graph on next slide…

7. 3 important things you must have on a graph:
Title
Labeled axis
Units

8. Collecting and analyzing data
Data: information
Quantitative: numbers by counting or measuring
Qualitative: descriptive
Tools used to collect
Journals/ computer
Graphs and charts
Drawing conclusions

9. Scientific Theory
Applies to a well tested explanation that unifies a broad range of observations and hypotheses.
Ex. Evolution, cell theory
No theory is considered absolute truth – law
Theories may be revised or replaced by a more useful explanation

10. Characteristics of Living Things
Are based on a universal genetic code
DNA

11. Living things:
Grow and develop
Cell division and differentiation

12. Living things: Respond to their environment
Stimulus – signal to which an organism responds

13. Living things: Reproduce Asexual – single organism produces offspring
Sexual – 2 parent cells unite to form new organism

14. Living Things
Maintain a stable internal environment - Homeostasis

15. Living things: Obtain and use material and energy
Metabolism – sum of all chemical reactions

16. Living things: Are cellular – made up of at least 1 cell
Smallest unit of life

17. Living things:
As a group – evolve – change over time