The Science of Life
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Biology
Organization
Cell
Unicellular
Multicellular
Organ
Tissue
Organelle
A. Made of one cell
B. The smallest unit that can perform
all life’s processes
C. Made of many cells
D. The study of life
E. The high degree of order within an
organism’s internal and external
parts and in its interactions with
the living world.
F. Tiny structures inside living cells
G. A group of similar cells working
together
H. A group of tissues that work
together to perform a specific job
in a living thing.
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Biological
molecule
Homeostasis
Metabolism
Cell Division
Development
Reproduction
Gene
I. The sum of all chemical reactions in
a living thing that take in and
transform energy and materials
from the environment
J. Formation of two new cells
K. Chemical compounds made up of
atoms
L. A short segment of DNA that had
coded instructions for a single trait
in an organism
M. To produce new organisms similar
to oneself
N. Process by which an organism
becomes a mature adult
O. To maintain stable internal
conditions
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Biology
Organization
Cell
Unicellular
Multicellular
Organ
Tissue
Organelle
D
E
B
A
C
H
G
F
Biological Molecule
Homeostasis
Metabolism
Cell Division
Development
Reproduction
Gene
K
O
I
J
N
M
L
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Biology is the study of life
◦ From the Latin:
 Bios = life
and
ology = study of
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1. Cellular Organization
◦ Organization is the high degree of
order within an organism’s internal
and external parts and in its
interactions with the living world.
◦ All living things are made of one or
more cells and these cells are highly
organized.
 Unicellular = made of one cell
 Multicellular = made of many cells
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Atoms are the smallest particle of
an element. They combine to
form:
Biological molecules which are
chemical compounds that join to
form:
Organelles —Each of these tiny
structures within a cell has a
special job to do to keep the cell
alive
The cell is the smallest unit of life
A group of cells working together
make up a tissue
A group of tissues make up an
organ
Organs combine to form organ
systems
An organism is a complete and
whole living thing
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2. Response to stimuli
◦ A stimulus is a sudden change in an organism’s
environment
◦ All organisms must be able to respond or react to
these sudden changes
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3. Homeostasis is the maintenance of a
stable level of internal conditions even
though environmental conditions are
constantly changing.
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4. Metabolism is the sum of all the chemical
reactions that take in and transform energy
and materials from the environment.
◦ Different organisms have different metabolic rates
 Describes as a fast or slow metabolism
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5. Growth and Development
◦ All living things grow or increase in size
◦ Growth results from the division and enlargement
of cells
◦ Cell division is the formation of two new cells from
an existing cell.
◦ Development is the process by which an organism
becomes a mature adult.
◦ A multicellular organism is composed of trillions of
specialized cells, all which developed from a single
cell, the fertilized egg.
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6. Reproduction
◦ All organisms produce new organisms like
themselves. This is essential for the survival of the
species.
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Hereditary information
is passed from parent
to offspring on the
coded information
molecule known as
deoxyribonucleic acid
or DNA.
◦ A gene is a short segment
of DNA that contains the
instructions for a single
trait of an organism.
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7. Change Through Time
◦ All populations of living things evolve or
change through time. This is important for
species survival in a changing world.
◦ This also helps to explain the diversity of lifeforms on Earth.
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Domain
Kingdom
Ecology
Ecosystem
Evolution
Natural
Selection
Adaptation
A. Communities of living species and
their environments
B. Branch of biology that studies how
organisms interact with the
environment
C. Largest division in the classification
of living things
D. Traits that improve an individual’s
ability to survive
E. Theory stating that organisms with
favorable traits are more likely to
survive and pass on those traits
F. Second largest division in the
classification of living things
G. Descent with modification
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Domain
Kingdom
Ecology
Ecosystem
Evolution
Natural Selection
Adaptation
C
F
B
A
G
E
D
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Three important
themes help explain the
living world and are
part of biology
◦ Diversity and Unity of Life
◦ Interdependence of
Organisms
◦ Evolution of Life
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1. Diversity and Unity of
Life
◦ These terms seem to
contradict each other
 Diversity = variety. Over 1.5
million species of living things
exist on Earth. They are
extremely different from each
other.
 Unity = similar. There are
certain genetic similarities
common to all living things,
no matter how different they
appear to be.
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All living things have a
genetic code found in the
DNA molecule.
They share certain genes,
yet no two types of
organisms have the same
full set of genes.
A tree of life places
organisms with more
similarities in their genes
on closer branches.
All life is connected, yet
there are different
lineages representing
different species.
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The three
branches
represent the
three Domains in
the living world:
Archaea, Bacteria,
and Eukarya
Most scientists
also recognize six
kingdoms:
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Archaeabacteria
Eubacteria
Protista
Fungi
Plantae
Animalia
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2. Interdependence of Organisms
◦ Organisms interact with each other. Nothing can
survive completely independent of another living
thing.
 Ecology =the branch of biology that studies how
organisms interact with each other and their
environment.
 Ecosystem = communities of living species and their
physical environments.
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3. Evolution of Life
◦ Populations of living organisms change through
time or “evolve”
 Evolution =descent with modification. It is the process
by which the inherited characteristics of a species
change over time.
 Natural Selection = theory that states organisms with
traits best suited to their environment will most likely
survive and pass on those favorable traits. It explains
how species evolve and new species emerge.
 Adaptation = traits that improve an individual’s ability
to survive. Genetic variety allows some organisms to
be born with favorable adaptations.
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Scientific Method
Observation
Hypothesis
Prediction
Experiment
Control group
Experimental group
Independent variable
Dependent variable
Theory
Peer review
A. Forecasts what would happen in a
test
B. Used to test a hypothesis
C. Organized set of steps used to
solve a problem
D. Provides a standard for comparison
E. The act of perceiving something
F. A proposed explanation
G. A highly tested and generally
accepted principle that explains an
observation
H. Experts critique each others work
I. A.k.a. manipulated variable
J. A.k.a responding variable
K. Group in which one factor is
different
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Scientific method
Observation
Hypothesis
Prediction
Experiment
Control group
Experimental group
Independent variable
Dependent variable
Theory
Peer review
C
E
F
A
B
D
K
I
J
G
H
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The scientific method is an
organized set of steps used to
solve problems:
◦ Make an Observation —perceive a
natural occurrence which causes you
to pose a question
◦ State the Question
◦ Hypothesize and Predict—give an
explanation that tries to answer the
question and then make predictions as
to what would happen if the
hypothesis were true.
◦ Experiment—design and run a test for
the hypothesis
◦ Analyze Data and Draw Conclusions
◦ Publish Conclusions—so that others
can verify, reject, or modify your
results.
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A good experiment is called a controlled
experiment. It has several parts:
◦ Control group —this group provides a normal
standard against which results are compared
◦ Experimental group —this group is identical to the
control group except for one factor
◦ Independent variable —the factor that changes in
an experiment. Also called the manipulated
variable.
◦ Dependent variable —the factor that is being
observed or measured. Also called the responding
variable.
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Scientists collect two types of data:
◦ Quantitative Data —data measured in numbers
◦ Qualitative Data —data recorded as a description of
something
◦ Both must be detailed
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A scientific theory is a
highly tested,
generally accepted
principle that explains
a vast number of
observations and
experimental data.
Examples: Cell
Theory, Quantum
Theory, Theory of
Relativity, Theory of
Natural Selection
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A typical research paper
has four sections:
◦ Introduction —states the
problem and hypothesis to
be tested
◦ Materials and Methods —
describes the experiment
◦ Results —states the findings
◦ Discussion —gives the
significance of the
experiment and future
directions the scientist will
take.
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The microscope will be used quite often
throughout this course. Proper use will be
covered in a lab activity.
The metric system will be used to take
measurements in several lab activities. The
metric system will be reviewed during that
time.