1. What does science mean to you?
The Science of Biology
What does science mean to you?
Investigate
Explain
Make predictions

2. Thinking Like a Scientist
Observations – gathering information and recording data
quantitative – involves characteristics that
can be measured
qualitative - involves characteristics that
are not measured
Interpret data – inferences may be made
Propose a hypothesis – possible explanation for an
observed phenomenon or possible answer to
a scientific question; must be testable

3. The experimental design

4. The experimental design
State the problem – statement or question based on an observation
Formulate a hypothesis – possible explanation of observed phenomenon
Set up a controlled experiment where only one variable is changed
independent variable – what you are changing
dependent variable – what you are measuring

5. The experimental design
Record and Analyze Results – using notebooks, drawings, computers
Drawing a Conclusion – use the evidence from the experiment to support or refute the hypothesis
Publish results – allows other scientists to repeat the experiment in order to verify the results
(The Experimental Design)

6. Does the experimental design work for everything?
How would you observe elephant behavior?
Field study – observations made without human interference
Would it be ethical to observe the effect of LSD on elephants? Lysergic acid diethylamide, a synthetic crystalline compound, that is a potent hallucinogenic drug

7. Can science answer all questions?
Is this painting beautiful?

8. What is the difference between a hypothesis, a theory, and a scientific law
A theory is well tested explanation that unifies a broad range of observations (Fig. 1-13)
A scientific law is true and is usually associated with a mathematical equation (Charles’ Law - Assuming that pressure remains constant, the volume and absolute temperature of a certain quantity of a gas are directly proportional. V/T=K)

9. Characteristics of life
Nerve Cell
Striated Muscle

10. Characteristics of life
All living things are made up of cells which are the smallest units of life (Fig. 1-15)
unicellular – single celled
multicellular – many celled
All living things reproduce
sexual – two parents produce offspring that are genetically unique
asexual – one parent, offspring are genetically identical

11. Characteristics of life

12. Characteristics of life

13. Characteristics of life
(amoeba – a single celled organism)
(hydra – a multicellular organism)
(budding in hydra - asexual reproduction)

14. Characteristics of life

15. Characteristics of life
Based on a universal genetic code
DNA – is the molecule that carries this code and determines the inherited traits of all organisms
Growth and Development
growth is an increase in the size and/or number of cells
development is when cells become specialized or differentiate (seed growth)

16. Characteristics of life

17. Characteristics of life
Obtain and Use Materials and Energy
Metabolism – all the chemical reactions within an organism
Respiration – process that releases energy by breaking down food molecules
aerobic – oxygen is required
anaerobic – oxygen is not required

18. Characteristics of life
Obtain and Use Materials and Energy
Plants convert solar energy into chemical energy in the process of photosynthesis
Animals obtain their energy by eating plants or other animals.

19. Characteristics of life

20. Characteristics of life
Respond to changes in the environment
seed germinates when watered
some animals migrate when temperatures change
Maintain a stable internal environment which is known as
Homeostasis

21. Characteristics of life

22. Characteristics of life

23. Characteristics of life
Groups of living things evolve over time. Changes are the result of characteristics being selected for or selected against.

24. Levels of Organization (Fig. 1-21)

25. Tools & Procedures of Scientists
International System of Units

27. Tools & Procedures of Scientists
International System of Units

28. Tools & Procedures of Scientists
Analyzing Data
(See Fig. 1-24)

29. Tools & Procedures of Scientists
Light microscope

30. Tools & Procedures of Scientists
Light microscope

31. Tools & Procedures of Scientists
Light microscope – any device that uses light to produce an enlarge view of an object
magnification – ratio of image size to object size
(ocular x objective)
resolution – ability of microscope to show two points
that are close together separately (sharpness of image)
compound microscope – 2 lenses, prepared specimens
must be thin enough for light to pass through
(see Appendix D)
stereomicroscope – study external or surface structure of
specimens

32. Tools & Procedures of Scientists
Electron Microscope

33. Tools & Procedures of Scientists
transmission electron – electron beams hit specimen and pass through, are absorbed, or scattered

34. Tools & Procedures of Scientists
scanning electron – electron beam is focused and passed back & forth over a surface; produces 3D images

35.
This site shows how various cells look when viewed through different types of microscopes.

36. Tools & Procedures of Scientists
Laboratory Techniques
cell cultures – maintain living cells or tissue in a culture medium outside of the body

37. Tools & Procedures of Scientists
Laboratory Techniques
cell fractionation – cells are broken into pieces and the different cell parts are separated at various speeds and durations to isolate components of different sizes, densities and shapes

38. Tools & Procedures of Scientists
Laboratory Techniques
centrifugation – liquid separation based on densities

39. Tools & Procedures of Scientists
Laboratory Techniques
electrophoresis – uses electric current to separate substances

40. Tools & Procedures of Scientists
Laboratory Techniques
computers – collect, store, analyze data, generate images of body tissue