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Study of Life
Chapter 1
Themes
AP Biology
2007-2008
Why study themes of Biology?
 Biology is an ever expanding body of
knowledge
too much to memorize it all
 need to generalize
 create a framework upon which to
organize new knowledge
 themes are the key to understanding
the nature of living organisms

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8 Themes in biology
 Science as a process of
inquiry called inductive reasoning

questioning & investigation
 Evolution
 Energy transfer
 Continuity & Change
 Relationship of structure to function
 Regulation
 Interdependence in nature
 Science, technology & society
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Science as a process of inquiry
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Science as a process of inquiry
 Built on repeatable observations &
testable, falsifiable hypotheses
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Natural selection
 Evolutionary change is a
product of the process of
natural selection –can produce
new species
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Organisms
don’t adapt;
Organisms have
adaptations.
"Nothing in biology
makes sense except in
the light of evolution."
-- Theodosius Dobzhansky
March 1973
Geneticist, Columbia University
(1900-1975)
AP Biology
2007-2008
Evolution explains unity & diversity (all
life is connected through evolution)
 Unity

what do organisms have in common & why do
similarities exist?
 common biochemistry & physiology
 evolutionary relationships
 connected through common ancestor
 Diversity

but why are there
differences?
 natural selection
 adaptations allow different
individuals to survive
in different environments
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The origin of species


Charles Darwin presented two ideas:
Current species arose from a succesion of ancestors
through “decent with modification “ (evolution)
 The mechanism of evolution is natural selection
He observed this by
1. Individuals in a population of any species vary in many
heritable traits
2. Any population can potentially produce far more
offspring than the environment can support
Result of these 2  a struggle for existence among variant
members of a population
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Organizing systems
 Making sense out of the diversity
 Hierarchical

scheme
Loss of order or free energy flow = death
Eastern gray squirrel
AP
Sciurus
Biology
carolinensis
3 Domains of Life
Bacteria, Archaea, Eukarya
Bacteria
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Archaea
Eukarya
Energy transfer
 Life is an open system

need input of energy
 energy flows through
 energy comes in,
energy goes out
 need a constant input

need input of materials
 nutrients are recycled
around & around
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DECOMPOSERS
ENTROPY RULES!
RULE, too!
nutrients
Energy utilization
You think
they’re eating…
They’re harvesting
energy!
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Continuity & change
 Continuity of life is based on heritable
information in the form of DNA

DNA – the genetic
material – carries
biological information
from one generation
to the next
You
can make more,
a lot like you!
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T
R
A
I
T
Form follows function
 The alignment of structure & function is
seen at all levels of biology
organism
cell
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organ
organelle
Regulation
 Organisms need to maintain a “steady state”
in the face of changing conditions


maintain homeostasis
achieve this through feedback
 monitor the body like a thermostat
 turn on when it’s needed, off when its not
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Interdependence
 No organism is an island standing alone

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communities, ecosystems
Science, technology & society
 Science & technology must function within
the rules of society

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ethics
Themes
 Science as a process of
inquiry

questioning & investigation
 Evolution
 Energy transfer
 Continuity & Change
 Relationship of structure to function
 Regulation
 Interdependence in nature
 Science, technology & society
AP Biology
What Makes Something Living?
 Living things share the same 7
characteristics:
A. Organization and cells
 B. Response to stimuli
 C. Homeostasis
 D. Metabolism
 E. Growth and development
 F. Reproduction
 G. Evolution

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ANY
QUESTIONS?
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