Biology: Exploring Life
 Biology

is the study of life.
All living things share similar characteristics
of life.
The basics
11 Characteristics of Life

Development- a change in body form from immature to
sexually mature
The basics
Organization of life
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Subatomic particles→
Atoms→
Molecules→
Macromolecules→
Organelles→
Cell→
Tissue→
Organ→
Organ system→
Organism
Classification of living things
Systematics groups species
into categories based on their
evolutionary relationships.
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

Human
Domain Archaea
•
Contains unicellular prokaryotes (bacteria)
•
Prokaryotes= cells that lack a membrane-bound nucleus & cell
structures.
•
Live in very harsh environments
-halophiles= salt lakes
-acidiphiles= soils
-thermophiles= hot springs
-methanogens= guts of humans, cows, etc.
Domain Bacteria

Bacteria are prokaryotic
cells.

They are found most
everywhere.
-skin
-water
-atmosphere
-mouth
Domain Eukarya
Eukaryotes= cells with a
membrane bound
nucleus & cell
structures
Eukaryotes are divided into
4 kingdoms:
1) Protists
2) Fungi
3) Plants
4) Animals

Taxomony is the assigning
every species with a two part
name (binomial).
 Bi= two
 Nomial = name
 Example: Pisum sativum
(Garden pea
 The first part of the name is
the genus and the second
part is the species.
 You must underline the
scientific name!
Carolus Linnaeus
 Scientific
Method- a process
that is used to gather evidence
that leads to understanding a
particular topic
The Scientific Method
Scientific Words
Complete these words on a vocab sheet in your folder.
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Scientific Method •
Hypothesis
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Inferences
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Independent
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Variable
Dependent Variable •
Experimental
Group
Control Group
Controlled Variable
(Look up Constant)
Analysis
Conclusion
Law
Theory
Every Experiment must have…
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Hypothesis- an educated guess based on
prior knowledge; can be tested by
experimentation
Independent Variable- the one variable
being tested, changed, and manipulated by
the scientist (There is only ONE
Independent Variable per experiment.)
*goes on x-axis when graphing
Dependent Variable- the variable that
changes in response to the independent
variable (usually it is what you are
measuring/collecting data on)
*goes on y-axis when graphing
Remember that you
NEVER prove anything;
Your hypothesis is either
accepted or rejected!
Hints to remember IV vs DV

__________ depends on ____________
(DV)
(IV)
Ex: Question- How does fertilizer effect
plant growth?
Hypothesis- If the plant receives more
fertilizer
than it will grow more.
 _Growth_ depends on Amount of fertilizer
(DV)
(IV)
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Let’s Test Your Brain Power!

Read the following scenario and answer
the questions.
 Identify:
 Homer notices that his shower is
covered in a strange green slime.
His friend Barney tells him that
coconut juice will get rid of the
green slime. Homer decides to
check this out by spraying half of
the shower with coconut juice. He
sprays the other half of the shower
with water. After 3 days of
"treatment" there is no change in
the appearance of the green slime
on either side of the shower.
Independent
Variable
2. Dependent
Variable
3. Control Group
4. Experimental
Group
1.

Control Group- must have one group/trial
in the experiment that lacks the
independent variable – used for
comparison

Experimental Group(s)- the groups/trials
that contain the independent variable

Controlled Variables- things that need to
stay constant throughout the experiment
Let’s Test Your Brain Power!
Practice
Bart believes that mice exposed to
radio waves will become extra strong
(maybe he's been reading too much
Radioactive Man). He decides to
perform this experiment by placing 10
mice near a radio for 5 hours. He
compared these 10 mice to another 10
mice that had not been exposed. His
test consisted of a heavy block of
wood that blocked the mouse food. he
found that 8 out of 10 of the mice
exposed to radio waves mice were
able to push the block away. 7 out of
10 of the other mice were able to do
the same.
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Identify:
1.
2.
3.
4.
5.
6.
Independent
Variable
Dependent
Variable
Control Group
Experimental
Group
What should
Bart’s
conclusion be?
How could
Bart’s
experiment be
improved?
Theory vs. Law
Theory – an explanation of a natural
phenomenon supported by many
observations and experiments over time.
Supported by evidence and enables
scientist to make accurate predictions.
 Law – describes relationships under
certain conditions in nature. Does not
explain why an event occurs, just
describes the relationship.
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Think: Individually, identify the following
statements as “Theory” or “Law.”
1)
2)
3)
4)
5)
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A hypothesis that is supported by experimental
results, many times.
It cannot be explained why the relationship exists.
All cells come from preexisting cells.
When blowing a bubble into the air, a force acts
upon it, causing it to fall to the floor.
The event is justified by evidence and an
explanation.
Pair: With the people at your table discuss your
answers.
Share: What are the correct answers?
The Answers Please!
1.
2.
3.
4.
5.
Theory
Law
Theory
Law
Theory
Crack Your Cranium
1.
a.
b.
c.
d.
A controlled
experiment allows
the scientist to
isolate and test
______.
A conclusion
A mass of
information
A single variable
Several variables
2. Measurements of a
plant’s growth over a
two-week period
represent ____.
a.Inferences
b.Variables
c.Hypothesis
d.Data
The Organization of the Biosphere
Biosphere: surface of the Earth (land, air, water) where life is found.
Population: all members of a species in a particular area
Community: made up of different populations
Ecosystem: Organisms interact with each other and the
physical environment.