1. Chapter 1 - The Science of Biology

2. Steps: observe to gather data - observation= gathering data
1-1 What is Science?
Goal= investigate and understand the natural world, to explain events, and to use those explanations to make useful predictions.
Scientfiic Method
Steps: observe to gather data
- observation= gathering data
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3. - hypothesis= proposed explanation for a set of observations
a. can be tested by experiment or data
b. disproved or supported by data
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4. Review:
1. Why is it important for you to know about biology?
2. Why is skepticism considered a valuable quality in a scientist?
3. What is the difference between qualitative and quantitative data?

5. ex: meat left on counter will grow maggots
1-2 How Scientists Work
Spontaneous generation- old theory that life could come from nonliving matter
ex: meat left on counter will grow maggots
Francesco Redi (1668)- created new hypothesis that flies laid eggs on the meat which hatched maggots
Used scientific method to create an experiment
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6. Designing an experiment
State the Problem
Form a Hypothesis
Set Up a Controlled Experiment
Record Results
Analyze Results
Draw a Conclusion
Publish Results
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7. - Controlled variables – kept the same
A Controlled Experiment is an experiment in which only one variable is changed at a time.
- Controlled variables – kept the same
- Manipulated variable – variable that is changed
- Responding variable – what is observed to changed in response to manipulated variable
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8. Figure 1-8 Redi’s Experiment on Spontaneous Generation (1668)
OBSERVATIONS: Flies land on meat that is left uncovered. Later, maggots appear on the meat.
HYPOTHESIS: Flies produce maggots.
PROCEDURE
Uncovered jars
Covered jars
Controlled Variables:
jars, type of meat,
location, temperature,
time
Several
days pass
Manipulated Variables:
gauze covering that
keeps flies away from
meat
Responding Variable:
whether maggots
appear
Maggots appear
No maggots appear
CONCLUSION: Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not occur.
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9. Repeating Investigations- controlled experiments should be reproducible
- three scientists supported Redi’s conclusions with additional experiments: Needham, Spallanzani, and Pasteur
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10. Figure 1-10 Spallanzani’s Experiment
Gravy is boiled.
Flask is
open.
Gravy is teeming
with microorganisms.
sealed.
Gravy is free of
microorganisms.
Figure 1-10 Spallanzani’s Experiment
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11. Figure 1-11 Pasteur’s Experiment
Curved neck
is removed.
Broth is
teeming with microorganisms.
Broth is boiled.
Broth is free of
microorganisms
for a year.
1864- Convinced scientists that spontaneous generation was invalid
Impacted industry and medical research
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12. Alternative experiments - Field studies view animals in environment
- Theory – well-tested hypothesis that explains a broad range of observations
-ex: theory of plate tectonics
- Biogenesis – “generating from life”; theory resulting from multiple experiments previously discussed
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13. Major Discoveries in History of Biology 1543 Andreas Vesalius 1628
Detailed study of human anatomy
1628
William Harvey
Circulation of blood
1673
Anton van Leeuwenhoek
Perfects simple microscope to observe cells
1859
Charles Darwin
Publishes theory of natural selection
1881
Louis Pasteur
Develops vaccine against anthrax
1953
Watson & Crick
Determined structure of DNA
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14. Review:
1. What was the manipulated variable in Redi’s experiment?
2. What was special about Pasteur’s apparatus?
3. How does a hypothesis become a theory?

15. If you were to make a list of characteristics of a living thing, what would be on it?

16. Biology- the science that seeks to understand the living world.
1-3 Studying Life
Biology- the science that seeks to understand the living world.
Characteristics of living things
Characteristic
Examples
Living things are made up of units called cells.
Many microorganisms consist of only a single cell. Animals and trees are multicellular.
Living things reproduce.
Maple trees reproduce sexually. A hydra can reproduce asexually by budding.
Living things are based on a universal genetic code.
Flies produce flies. Dogs produce dogs.
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17. Characteristic Examples
Living things grow and develop.
Flies begin life as eggs, then become maggots, and then become adult flies.
Living things obtain and use materials and energy.
Plants obtain their energy from sunlight. Animals obtain their energy from the food they eat.
Living things respond to their environment.
Leaves and stems of plants grow toward light.
Living things maintain a stable internal environment.
Despite changes in the temperature of the environment, a robin maintains a constant body temperature.
Taken as a group, living things change over time.
Plants that live in the desert survive because they have become adapted to the conditions of the desert.
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18. -Cell- collection of living matter enclosed in a barrier
Important terms
-Cell- collection of living matter enclosed in a barrier
-Sexual reproduction- two parents
-Asexual reproduction- one parent
-Metabolism- all chemical reactions in an organism
-Stimulus- signal to which an organism responds
-Homeostasis- process by which organisms maintain internal conditions
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19. -Zoologists- study animals -Botanists- study plants
Branches of Biology
-Zoologists- study animals
-Botanists- study plants
-Paleontologists- study ancient life
-Molecular biologists – study the chemistry of living organisms
-Population biologists – study the interactions of animals
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20. Figure 1-21 Levels of Organization
Biosphere
Ecosystem
Community
Population
The part of Earth
that contains all
ecosystems
Community and
its nonliving
surroundings
Populations that
live together in a
defined area
Group of
organisms of one
type that live in
the same area
Hawk, snake, bison, prairie dog, grass, stream, rocks, air
Hawk, snake, bison, prairie dog, grass
Bison herd
Figure Levels of Organization
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21. Individual living thing Tissues, organs, and organ systems Smallest
Organism
Groups of
Cells
Molecules
Individual living
thing
Tissues, organs,
and organ
systems
Smallest
functional
unit of life
Groups of atoms;
smallest unit of
most chemical
compounds
Bison
Nervous tissue
Nervous system
Brain
Nerve cell
Water
DNA
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22. Review:
1. Which characteristics of life does an automobile have? Why isn’t it considered a living thing?
2. In what context have you heard about metabolism before today?
3. What is another type of biologist not mentioned in the notes, and what do they study?

23. Click to play “It’s Alive Part 1”

24. Click to play “It’s Alive part 2”

25. 1-4 Tools and Procedures
The METRIC system- decimal system of measurement whose units are based on multiples of ten
Kilo
Hecto
Deka
base
deci
centi
milli Km Hm Dm m
meter dm cm mm
0.001
0.01
0.1 1 10
100
1000
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26. Analyzing Biological Data
tables and graphs are used to view trends and patterns in the data
Water Released and Absorbed by Tree
Time
Absorbed
by Roots
(g/h)
Released
by Leaves
8 AM
10 AM
12 PM
2 PM
4 PM
6 PM
8 PM 5 2 10 14 9 6 4 1 12 17 16 3
Water released by leaves
Water absorbed by roots
Relative Rates (g/h) 20 15
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27. Mag 1,000,000 times but require vacuum
Microscopes
Light microscopes- produce magnified images by focusing visible light rays
Mag 1000 times
Electron microscopes- produce magnified images by focusing beams of electrons
Mag 1,000,000 times but require vacuum
Transmission electron microscopes (TEMs)- shine beam of electrons through thin specimen
Scanning electron microscopes (SEMs)- scan the surface of specimen with electrons to make 3D image
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28. Review:
1. How many meters are in a kilometer?
2. How many centigrams are in a gram?
3. What must always be included on a graph?
4. TEMs and SEMs require a vacuumed environment. How does this affect the specimen?