1. Biology: The Study of Life
Chapter 1
Biology: The Study of Life

2. Science
-an organized way of using evidence to learn about the natural world
-the body of knowledge that scientists have built up
What is the goal of science?
To investigate and understand the natural world,
to explain events in the natural world
and to use those explanations to make useful predictions
**Scientists propose explanations that can be tested by examining evidence
Why does it rain?

4. Evidence Based on Observation
-gathering information about events or processes;
-involves the five senses
Data
-the information gleaned from your observations
-Qualitative vs. quantitative data

5. qualitative data? Quantitative?
Which of your observations can be considered
qualitative data? Quantitative?

7. Sense Observation Inference
See
Wet pavement
-rained
-s/o washed their car
Hear
A bird singing
-mark a territory
-attract a mate
Smell
Touch
Sticky tabletop
-s/o spilled syrup
Taste

8. -interpretation based upon prior knowledge or experience
INFERENCE
-interpretation based upon prior knowledge or experience
ex: Since I cannot test all of the bacteria & sequence all of them, then….
HYPOTHESIS
-a proposed scientific explanation for a set of observations or an answer to a scientific question
-experiment
-gather more data

9. The way it was : Aha!!! Meat --- maggots Grain --- mice
Dung --- beetles
Aha!!!
Spontaneous generation-
life arising from nonliving matter
1668-Franscesco Redi said…

10. 3. Controlled Experiment 4. Record and Analyze Results
Scientific Method- problem-solving for scientific questions
1. State the problem
2. Hypothesis
3. Controlled Experiment
4. Record and Analyze Results
5. Draw conclusions

11. -Manipulated/Independent Variable -Responding/Dependent Variable
3. Controlled Experiment
Whenever possible, a hypothesis should be tested an experiment in which only one variable is changed at a time. All other variables
should be kept unchanged or controlled
Why?
-Manipulated/Independent Variable
-Responding/Dependent Variable -

12. Spontaneous generation of maggots did not occur!
Redi’s observation: Maggots appeared on meat a few days after flies were present
Redi’s hypothesis: Flies laid eggs to small for people to see and produced maggots
Conclusion: Maggots form only when flies come in contact with meat.
Spontaneous generation of maggots did not occur!

13. Quick quiz:
What was Redi’s hypothesis?
What were the controlled variables (give 2)
What was the manipulated variable?
What was the question of the responding
variable?
Why did he design an experiment testing only
one variable?

14. He observed
He hypothesized
He experimented He
recorded
He concluded

15. Pasteur’s experiment disproved spontaneous generation

16. Jar of pasta sauce Once it is opened, the jar must be kept
in the refrigerator to keep the contents
from spoiling.
Q: What can you infer from Pasteur’s work
about why an opened jar must be kept in a refrigerator?
Q: Describe a controlled experiment to test the hypothesis that you propose based upon your answer to the first question?

17. Theory Theoretical? “That’s just in theory”
A well-tested explanation that unifies a broad ranges of observations
A well –supported hypothesis
Not absolute truth!!

18. 8 Characteristics of Life
Cells
a. Unicellular
b. Multicellular
Reproduction
a. asexual reproduction
b. sexual reproduction
3. Genetic Code
4. Growth & Development
5. Obtain and use Energy
a. metabolism
b.photosynthesis
6. Respond to the environment
a. stimulus
7. Homeostasis
8.Evolution

19. 1. Cells-the smallest and basic unit of life
Unicellular vs. multicellular

20. 2. Reproduction
asexual vs. sexual

21. 3. Genetic Code
-our directions for inheritance (DNA)

22. 4. Growth & Development Growth Changing shape & structure
Development Cells look diferent/diferent functions
Differentiation Getting larger

23. 5. Obtain & Use Energy
Metabolism-the total of all chemical reactions

24. 6. Response to the environment
stimulus…..response

25. maintain constant internal conditions
7. Homeostasis-
maintain constant internal conditions

26. 8. Evolution
The tree is rooted in the ancestral tetrapoda (amphibia).

27. Levels of Organization:
Biosphere
Ecosystem
Community
Population
Organism
Groups of Cells
Organ Systems
Organs
Tissues
Cells
Molecules
Atoms

29. Science,Technology and Society