Chapter One:
Science as a Process
Ch. 1.1
Intro to Biology &
Characteristics of Life
SCIENCE
• The continuous effort to discover and
increase human knowledge through
research
• The process of observing, explaining,
and understanding our world
• Does NOT include “supernatural”
explanations
Biology
• “Bio” = life
“ology” = study of
• The study of life (organisms)
• Answers questions about the natural
world:
– How they work
– How they interact with the environment
– How they change over time
Branches of Biology
1. Anatomy: external &
internal structures of
organisms
2. Ecology: interactions
between organisms and
their environment
3. Cytology: structure &
function of cells
4. Botany: plants
5. Genetics: heredity, how traits pass
from parent to offspring
6. Microbiology: “micro” = small,
organisms seen with a
microscope
7. Taxonomy: classification
8. Zoology: animals
Characteristics of Life:
1.
2.
3.
4.
5.
6.
7.
Organisms are made of cells.
Respond to stimuli.
All living things maintain homeostasis.
Organisms use energy (metabolism).
All living things grow and develop.
All living things reproduce.
Living things change through time.
Homeostasis
• Stable internal conditions
• Ex:
– Temperature
• Ex: Thermostat
– Water intake
– Food intake
– pH
Metabolism
• Sum of all chemical rxns that take
in & transform E & materials from
the environment
• Photosynthesis: converts light E
into chemical E
• Cellular Respiration: converts
organic cmpds into usable E
(ATP)
Maple vs. robot toy
Themes in Biology
&
The Scientific Method
Ch. 1.2
Themes in Biology
1. Diversity and Unity of Life
2. Interdependence of Organisms
3. Evolution of Life
1. Diversity and Unity of Life
• Diversity = variety of life
– Cell = basic unit of life
– Highly organized
– Unicellular vs. Multicellular
– Cell differentiation
Levels of Biological
Organization
Place the following terms in
the appropriate places on
the pyramid
Biosphere
Population
Biome
Organism
Community
Ecosystem
Levels of Biological
Organization
Place the following terms in
the appropriate places on
the pyramid
Organ Systems Cell
Atom
Organ Tissue
Molecule
Organism
• Unity= all living things have features
in common
– The genetic code; the heredity info. in
DNA
– Contain organelles; cellular structures
that carry out specific functions
– “Tree of Life”; has 3 main branches
called domains and 6 major categories
called kingdoms
“Tree of Life”
2. Interdependence of Organisms
• Organisms interact with each
other and the living world
– Area of science known as Ecology
– Ecosystems are communities of
living species & their physical
environment
1. Can you name some parts of an ecosystem?
2. How have humans affected the environment?
3. Evolution of Life
• Populations of living organisms
change over time
• Descent with modification
• Occurs by natural selection;
organisms with more favorable
traits survive a changing
environment and reproduce more
successfully.
• Adaptations are traits that
improve an organisms chance of
survival.
Ch.1.3
The Scientific Method
• How problems are solved!
– Scientists use controlled methods to
collect observable evidence to answer
questions about natural phenomena
– YouTube - Scientific Method MTV
– Put it to the Test
Steps of the Scientific Method
1. Define the problem.
2. Collect information.
Qualitative vs. quantitative
3. Form a hypothesis.
– a statement that can explain a
scientists observations and data
– Must be testable
– Educated guess that can be proven
FALSE
– Written as an “if-than” statement
4. Test the hypothesis.
– Controlled experiments test variables by
comparing a control group with an
experimental group.
– The independent (manipulated) variable
is the one that is changed by the scientist.
– The dependent (responding) variable
changes in response to the change made
to the independent variable.
Hypothesis Examples
• If skin cancer is related to ultraviolet light ,
then people with a high exposure to uv light
will have a higher frequency of skin cancer.
• If leaf color change is related to temperature ,
then exposing plants to low temperatures will
result in changes in leaf color.
• In the statements above the dependent variable is
blue and the independent variable is red.
5. Observe & record data.
6. Draw conclusions.
–
–
Support or refute hypothesis
A theory may be formed after many
hypotheses have been tested and supported by
much experimental evidence.
7. Report research methods & findings.
–
–
Scientific journals
Lab reports
Mythbusters Example
• Identify the hypothesis, control,
independent and dependent
variables in the following
experiment
• Mythbusters Plant Experiment part 1
• Mythbusters Plant Experiment part 2
Presenting Scientific Findings
• Tables- used to organize data
Graphs are used to visually
represent data
 Bar graphs- illustrate comparisons
 Line graphs- recognize patterns or
trends
 Pie graphs- represent percentages
 Title of graphs should include
dependent and independent variables
 Y-axis has the dependent variable
 X-axis has the independent variable
Scientific Method Review
• Tutorial Video Review
Units of Measurement
• Scientists use one system of
measurement, the metric system
( SI system)
• Decimal system based on powers of 10
• SI has 7 base units
Microscopes
Light Compound Microscope (LM):
• used to see small organisms
and cells
• transparent specimen is
mounted on glass slide
• Light passes through the
specimen
(pg. 21, parts of the microscope)
Electron Microscopes
-
Use a beam of electrons
to produce an enlarged
image of a specimen
1) Transmission electron
microscope (TEM)• electrons sent through a
thin specimen
• cannot view living
specimens
• 200,000 x magnification
2) Scanning electron microscope (SEM)
• electrons pass over specimen
producing a 3D image
• 100,000 x magnification
• cannot view living organisms