1. Chapter 2
The Science of Biology

2. Science = to know Based on inquiry
What is science?
Science = to know
Based on inquiry
Inquiry – asking questions about observations in nature and actively seeking answers

3. Observation – use of the senses to gather and record information about structures or processes in nature

4. Data – recorded observations
Quantitative data – observations recorded as measurements
Qualitative data – observations in the form of descriptions

5. Ex. Human Genome Project Some discoveries are accidental
Discovery Science
Discovery Science – science that describes natural structures or processes as accurately as possible through careful observation and data collection
Ex. Human Genome Project
Some discoveries are accidental
Ex. Alexander Flemming (Penicillin)

6. Inference – Logical conclusion based on observations
Often use prior knowledge
Help to refine general questions – more specific
Generalizations – general conclusion
Ex. All living things are made of cells

7. Hypothesis-Based Science
Scientific method - an organized approach to help understand how the natural world works

8. Scientific Method Steps
1. Observation
Act of perceiving a natural occurrence that creates questions

9. Scientific Method Steps
2. Hypothesis
Used to answer question(s) by proposing an explanation (use “if…..then” statements)

10. Scientific Method Steps
3. Prediction
Statement that forecasts what would happen in a test situation if the hypothesis were true

11. Scientific Method Steps
4. Experiment
Controlled tests
Control group – a group that serves as a standard of comparison with another group

12. Experimental group – the group that contains the independent variable
Independent Variable – the factor that is manipulated
Dependent Variable – factor that changes in response to the independent variable

13. Scientific Method Steps
5. Collect and Analyze data
Gather data from experiment and evaluate state if hypothesis and prediction are supported/true
Evidence – collected body of data from observations and experiments

14. Scientific Method Steps
6. Conclusion/Publishing
State if hypothesis and prediction are supported and true based on data analysis
Theory – explanation of some phenomenon that has been tested to be true several times

15. Model – physical, mental, or mathematical representations of how people understand a process or an idea
Ex. 3-D object, graph, equation, drawing
Allow work to be analyzed by scientific peers/public.
Work is reviewed and critiqued

16. Technology (applied science)
Applying scientific understanding for some specific purpose
Ex. Engineering, biotechnology

17. Tools and Techniques
Microscope – tool that visually enlarges an object
Light Microscopes
Light that passes from an object through a lens is bent so that the object looks either larger or smaller
Lens – piece of glass that has been shaped to bend light

18. Simple microscope – only one lens Ex. Magnifying glass (magnify 10x)
Tools and Techniques
Simple microscope – only one lens
Ex. Magnifying glass (magnify 10x)
Compound microscope – 2 or more lenses

19. Ocular lens – found in eyepiece
Objective lens – found on nosepiece
Each objective lens has a different magnification

20. Tools and Techniques Total magnification = Ocular x Objective
Ocular lens (10x)
Objective lens (4x, 10x, 40x)
Ex Low Power x X 4x = 40
Midrange x X 10x = 100
High Power x X 40x = 400
Parts of a Microscope

21. Resolution – measure of how clear an object appears
Tools and Techniques
Resolution – measure of how clear an object appears
As magnification increases, resolution decreases

22. Field of view – Area of light that is seen when looking through a microscope
As magnification increases, field of view decreases
Amount of light is controlled by diaphragm
Parfocal – microscope stays in focus as objective lenses are changed

23. Tools and Techniques Electron Microscopes
Powerful microscope that uses tiny negatively charge particles called electrons to magnify objects
Can magnify up to 300,000x
Resolution can be up to a million times better than the human eye
Very expensive

24. Units of Measurement
Metric System (the international system of units)
Standard system of measurement scientists use to compare results
Based on the powers of “10”

25. Mass – amount of matter an object has
Units of Measurement
Mass and Weight
Mass – amount of matter an object has
Weight – amount of matter + pull of gravity
Gram (g) – basic unit of mass
Tool for measurement - balance

26. Units of Measurement
Length
Length – measure of distance between two points
Meter (m) – basic unit of length
Tool for measurement – ruler, meterstick

27. Units of Measurement Volume
Volume – amount of space an object takes up
Liter (L) (Quart)– basic unit of volume
Tool for measurement – graduated cylinder/ beaker/flask/pipette

28. Fahrenheit and Celsius
Units of Measurement
Temperature
Temperature – measure of how hot or how cold an object/substance is
Fahrenheit and Celsius
0ºC - 32ºF Freezing
100ºC - 212ºF Boiling
22ºC - 72ºF Room Temperature