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Thursday, August 20
• Complete the summer
work display board
according to the
directions you picked up
when you came in.
Evolution, the Themes of
Biology and Scientific
Inquiry
What are Themes?
• General principles or ideas that
occur over and over.
• In the new AP curriculum, the
themes are “the Big Ideas”.
The 4 Big Ideas: E2 – I2
1. Evolution
2. Energy
3. Information
4. Interactions
The Big Ideas – E2 - I2
1. Evolution – the process of evolution drives the
diversity and unity of life.
2. Energy – biological systems utilize free energy
and molecular building blocks to grow, to
reproduce, and to maintain dynamic homeostasis.
3. Information – living systems store, retrieve,
transmit and respond to information essential to
life processes.
4. Interactions – biological systems interact and
these systems and their interactions possess
complex properties.
Why Big Ideas?
• We will see the Big Ideas at various
times throughout the course.
• The Big Ideas will be the
“connectors” between the content of
the course.
Emergent Properties
• Emergent properties result from the arrangement
and interaction of parts within a system
• Emergent properties characterize nonbiological
entities as well
– For example, a functioning bicycle emerges only
when all of the necessary parts connect in the
correct way
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
The Power and Limitations of Reductionism
• Reductionism is the reduction of complex systems
to simpler components that are more manageable
to study
– For example, the molecular structure of DNA
• An understanding of biology balances
reductionism with the study of emergent properties
– For example, new understanding comes from
studying the interactions of DNA with other
molecules
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Systems Biology
• A system is a combination of components that
function together
• Systems biology constructs models for the
dynamic behavior of whole biological systems
• The systems approach poses questions such as:
– How does a drug for blood pressure affect other
organs?
– How does increasing CO2 alter the biosphere?
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Theme: Organisms interact with their
environments, exchanging matter and energy
• Every organism interacts with its environment,
including nonliving factors and other organisms
• Both organisms and their environments are
affected by the interactions between them
– For example, a tree takes up water and minerals
from the soil and carbon dioxide from the air; the
tree releases oxygen to the air and roots help form
soil
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Ecosystem Dynamics
• The dynamics of an ecosystem include two major
processes:
– Cycling of nutrients, in which materials acquired by
plants eventually return to the soil
– The flow of energy from sunlight to producers to
consumers
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 1-5
Sunlight
Ecosystem
Cycling
of
chemical
nutrients
Producers
(plants and other
photosynthetic
organisms)
Heat
Chemical energy
Consumers
(such as animals)
Heat
Energy Conversion
• Work requires a source of energy
• Energy can be stored in different forms, for
example, light, chemical, kinetic, or thermal
• The energy exchange between an organism and
its environment often involves energy
transformations
• Energy flows through an ecosystem, usually
entering as light and exiting as heat
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Theme: Structure and function are correlated at
all levels of biological organization
• Structure and function of living organisms are
closely related
– For example, a leaf is thin and flat, maximizing the
capture of light by chloroplasts
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Theme: Cells are an organism’s basic units of
structure and function
• The cell is the lowest level of organization that can
perform all activities required for life
• All cells:
– Are enclosed by a membrane
– Use DNA as their genetic information
• The ability of cells to divide is the basis of all
reproduction, growth, and repair of multicellular
organisms
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 1-7
25 µm
• A eukaryotic cell has membrane-enclosed
organelles, the largest of which is usually the
nucleus
• By comparison, a prokaryotic cell is simpler and
usually smaller, and does not contain a nucleus or
other membrane-enclosed organelles
• Bacteria and Archaea are prokaryotic; plants,
animals, fungi, and all other forms of life are
eukaryotic
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 1-8
Prokaryotic cell
Eukaryotic cell
Membrane
DNA
(no nucleus)
Membrane
Cytoplasm
Organelles
Nucleus (contains DNA)
1 µm
Theme: The continuity of life is based on
heritable information in the form of DNA
• Chromosomes contain most of a cell’s genetic
material in the form of DNA (deoxyribonucleic
acid)
• DNA is the substance of genes
• Genes are the units of inheritance that transmit
information from parents to offspring
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
DNA Structure and Function
• Each chromosome has one long DNA molecule
with hundreds or thousands of genes
• DNA is inherited by offspring from their parents
• DNA controls the development and maintenance
of organisms
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 1-9
Sperm cell
Nuclei
containing
DNA
Egg cell
Fertilized egg
with DNA from
both parents
Embryo’s cells with
copies of inherited DNA
Offspring with traits
inherited from
both parents
• Each DNA molecule is made up of two long chains
arranged in a double helix
• Each link of a chain is one of four kinds of
chemical building blocks called nucleotides
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 1-10
Nucleus
DNA
Nucleotide
Cell
(a) DNA double helix
(b) Single strand of DNA
• Genes control protein production indirectly
• DNA is transcribed into RNA then translated into a
protein
• An organism’s genome is its entire set of genetic
instructions
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Systems Biology at the Levels of Cells and
Molecules
• The human genome and those of many other
organisms have been sequenced using DNAsequencing machines
• Knowledge of a cell’s genes and proteins can be
integrated using a systems approach
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Friday, August 21
• What defining characteristic of life is
observed when a jogging man begins
to sweat and when a plant closes its
stomata openings in its leaves? Why?
– A. Metabolism
– B. Heredity
– C. Cellular makeup
– D. Homeostasis
Question:
• How do we know what is alive and
what is not?
• Biology is the study of Life.
• So, what are the properties of Life?
• Goal – not to memorize the list of
characteristics, but to be able to
discuss and apply them.
1. Order
• Living things are highly organized
in structure and function.
• Analyzing a biological structure gives
us clues about what it does and how
it works.
• Structure and Function are related at
all levels.
2. Reproduction
• Organisms reproduce their own kind.
3. Nucleic Acids
• Life on Earth uses the nucleic acids
and codes for Heritable Information.
4. Growth & Development
• Organisms increase in size and
complexity.
• Growth - increase in size.
• Development - increase in complexity.
• Life - grows by internal changes.
5. Energy Processing
• Organisms take in energy and
transform it to do work.
• Organisms are “open” systems, they
must continually take in energy.
6. Response To Environment
• Organisms respond to changes or
stimuli in their environment.
7. Regulation
• Life processes must be controlled
and adjusted.
• Organisms maintain their internal
environment within tolerable limits by
homeostasis.
• “homeo” = same
• “stasis” = state
Interactions- Feedback Regulation
Negative
Feedback- a loop
where the
response reduces
the initial stimulus.
1.11 picture
• Positive
Feedback- end
product speeds
up its own
production.
• -Clotting of blood
in response to
injury. Chemicals
are released to
attract more
platelets.
8. Evolutionary Adaptation
• Organisms change over time because
of successful adaptations to their
environment.
• Organisms must have successful
adaptations, move, or die!
Is this a “good”
adaptation?
9. The Cell Is the “basic unit”
of Life
Levels of Biological Organization
•
•
•
•
•
•
•
•
•
•
1. Biosphere
2. Ecosystem
3. Communities
4. Populations
5. Organisms
6. Organs and Organ Systems
7. Tissues
8. Cells
9. Organelles
10. Molecules
Levels of Biological Organization
• Biosphere- all life
on Earth and all
places where life
exists.
• Ecosystem- all
living and
nonliving things
in a particular
area.
• Communities
• Array of organisms
inhabiting a particular
ecosystem.
• Populations
• All the individuals
of a particular
species
• Organismsindividual living
things
• Organs and
Organ SystemBody part that
carries out
specific function.
• Tissues – Group of cells
that work together to
perform a specialized
structure.
• Cells- life’s fundamental
unit of structure and
function. Cell is about
40um, about 500 would
reach across a coin.
• Organellesfunctional
components
present in cells.
• Molecules- chemical
structure consisting
of 2 or more atoms.
Chlorophyll
molecule
Monday, August 24
• What is the Theory of
evolution by natural
selection? Who is
responsible for this
Theory?
Basic Evolution
• Nothing in Biology makes sense
except in the light of Evolution.
– Theodosius Dobzhansky
American Biology Teacher 35:125-129, 1973.
Important Notes:
1. organisms survive because of their
adaptations, they do not adapt to
survive.
2. individuals do not evolve,
populations do.
Evolution Success is by:
1. Survival - the organism has to live.
2. Reproduction – the organism has to
leave progeny behind.
Grouping Species: The Basic Idea
• Taxonomy is the branch of biology that names and
classifies species into groups of increasing
breadth
• Domains, followed by kingdoms, are the broadest
units of classification
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 1-14
Species Genus Family Order
Class
Phylum Kingdom Domain
Ursus americanus
(American black bear)
Ursus
Ursidae
Carnivora
Mammalia
Chordata
Animalia
Eukarya
The Three Domains of Life
• The three-domain system is currently used, and
replaces the old five-kingdom system
• Domain Bacteria and domain Archaea comprise
the prokaryotes
• Domain Eukarya includes all eukaryotic
organisms
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 1-15a
(a) DOMAIN BACTERIA
Fig. 1-15b
(b) DOMAIN ARCHAEA
• The domain Eukarya includes three multicellular
kingdoms:
– Plantae
– Fungi
– Animalia
• Other eukaryotic organisms were formerly
grouped into a kingdom called Protista, though
these are now often grouped into many separate
kingdoms
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 1-15d
Protists
Fig. 1-15e
Kingdom Fungi
Fig. 1-15f
Kingdom Plantae
Fig. 1-15g
Kingdom Animalia
Unity in the Diversity of Life
• A striking unity underlies the diversity of life; for
example:
– DNA is the universal genetic language common to
all organisms
– Unity is evident in many features of cell structure
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Charles Darwin and the Theory of Natural
Selection
• Fossils and other evidence document the
evolution of life on Earth over billions of years
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 1-17
• Charles Darwin published On the Origin of
Species by Means of Natural Selection in 1859
• Darwin made two main points:
– Species showed evidence of “descent with
modification” from common ancestors
– Natural selection is the mechanism behind “descent
with modification”
• Darwin’s theory explained the duality of unity and
diversity
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 1-18
Fig. 1-19
• Darwin observed that:
– Individuals in a population have traits that vary
– Many of these traits are heritable (passed from
parents to offspring)
– More offspring are produced than survive
– Competition is inevitable
– Species generally suit their environment
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Darwin inferred that:
– Individuals that are best suited to their environment
are more likely to survive and reproduce
– Over time, more individuals in a population will have
the advantageous traits
• In other words, the natural environment “selects”
for beneficial traits
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 1-20
1
Population
with varied
inherited traits.
2
Elimination
of individuals
with certain
traits.
3
Reproduction
of survivors.
4
Increasing
frequency
of traits that
enhance
survival and
reproductive
success.
• Natural selection is often evident in adaptations of
organisms to their way of life and environment
• Bat wings are an example of adaptation
Video: Soaring Hawk
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
The Tree of Life
• “Unity in diversity” arises from “descent with
modification”
– For example, the forelimb of the bat, human, horse
and the whale flipper all share a common skeletal
architecture
• Fossils provide additional evidence of anatomical
unity from descent with modification
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Darwin proposed that natural selection could
cause an ancestral species to give rise to two or
more descendent species
– For example, the finch species of the Galápagos
Islands
• Evolutionary relationships are often illustrated with
tree-like diagrams that show ancestors and their
descendents
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 1-22
Insect-eaters
Warbler finches
Gray warbler finch
Certhidea fusca
Bud-eater
Seed-eater
COMMON
ANCESTOR
Green warbler finch
Certhidea olivacea
Sharp-beaked
ground finch
Geospiza difficilis
Vegetarian finch
Platyspiza crassirostris
Mangrove finch
Cactospiza heliobates
Insect-eaters
Tree finches
Woodpecker finch
Cactospiza pallida
Medium tree finch
Camarhynchus pauper
Large tree finch
Camarhynchus
psittacula
Small tree finch
Camarhynchus
parvulus
Cactus-flowereaters
Seed-eaters
Ground finches
Large cactus
ground finch
Geospiza conirostris
Cactus ground finch
Geospiza scandens
Small ground finch
Geospiza fuliginosa
Medium ground finch
Geospiza fortis
Large ground finch
Geospiza magnirostris
Video: Albatross Courtship Ritual
Video: Blue-footed Boobies Courtship Ritual
Video: Galápagos Islands Overview
Video: Galápagos Marine Iguana
Video: Galápagos Sea Lion
Video: Galápagos Tortoise
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Evolution in AP Biology
1. What is the adaptive value of
________?
2. Why has ______ persisted over
time?
3. How does _____ increase survival
or reproduction?
Science is:
• A process.
• A way of “knowing”.
• Based on observations and
experiments.
Observations:
• Are the “keystone” to Science.
• If it can’t be “observed”, it can’t be
studied by the Scientific Method.
• Can be made through your senses
or through the use of tools.
Two types of Science
1. Discovery or Descriptive Science
– Naturalists, human genome
– Based on observations, but may lead to
experiments
– Inductive Reasoning – logic flows from a set
of specific observations to a general
conclusion
2. Hypothesis based Science
– Science by experimentation
– Hypothesis testing in the form of
“If…then…”
– Deductive Reasoning - logic flows
from general to specific
Example
• When I throw a ball in the air, why
does it come back down?
• Inductive
– Whenever I have thrown a ball in the past,
it always comes back down.
– Specific observations to general
conclusion.
• Deductive
– Gravity attracts two objects.
– If I throw the ball into the air, then gravity
should draw the ball to the earth.
Scientific Method:
• Outlines a series of steps for
answering questions.
• Note – goal is NOT to memorize
these steps.
• Obtains “evidence” through the use
of experiments.
Scientific Method Steps
1. Identify the problem.
2. What is already known?
3. Formulate a hypothesis.
4. Conduct an experiment changing one
variable at a time. (Why?)
5. Collect data. Have replicates. (Why?)
6.Compare data to hypothesis.
Does the data support the hypothesis?
7. Conclusions and new hypothesis
Comment
• Nothing is ever proven in science.
– Can only be disproven
• Experiments either support or fail to
support a particular hypothesis.
• Disproving a hypothesis is as
important as supporting it.
• We will learn about the 7 Science
Practices in Lab.
Theory (Capital T)
• Broader in scope than hypothesis.
• Not determined by single experiment,
but have been supported by many
experiments by many scientists.
• Comprehensive explanation supported
by abundance of evidence.
• Theories allow predictions.
Examples of Theories
•
•
•
•
•
Atomic Theory
Gravitational Theory
Theory of Relativity
Cell Theory
Theory of Evolution by Natural
Selection
Lower case t theories
• Used in everyday language, but are
NOT the same as a Theory.
• Not predictive, Not testable.
• Not supported by evidence
• Don’t confuse Theory with theory.
Chapter Summary
• Big Ideas can provide a common
framework for learning Biology.
• What are the characteristics of Life?
• How does Science work?
• Evolution’s role in the study of
Biology.