Download Ch. 1 Themes of Life

LECTURE PRESENTATIONS
For CAMPBELL BIOLOGY, NINTH EDITION
Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert B. Jackson
Chapter 1
Introduction: Themes in the
Study of Life
Lectures by
Erin Barley
Kathleen Fitzpatrick
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What is Biology?
• Biology is the _________________
• Biologists ask questions such as:
• Life defies a simple, one-sentence definition
• Life is recognized by ____________________
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Properties of Life
Figure 1.3
______
______________
______________
___________
___________
__________
_____________
_____________
_________
___________
___________
Levels of Biological Organization
__________
___________
__________
___________
___________
__________
___________
____________
___________
_____________
_________
Emergent Properties
• Life exists from a ___________ to a global scale
• New properties emerge at __________ of complexity
• Emergent properties
• 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
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The Power and Limitations of Reductionism
• Reductionism –
– For example, studying the molecular structure of
DNA helps us to understand the chemical basis of
inheritance
• 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
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Systems Biology
• System –
• 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?
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Theme: Organisms Interact with Other
Organisms and the Physical Environment
• Every organism interacts with its environment, including
nonliving factors and other organisms
• Both organisms and their environments are affected by
these interactions
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Figure 1.5a
• How do we affect our environment?
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Theme: Life Requires Energy Transfer
and Transformation
• _________ is used to perform life’s activities at all levels
– Work, including moving, growing, and reproducing, requires a
source of energy
• Living organisms transform energy from one form to
another
• Energy flows through an ecosystem, usually entering as
________ and exiting as ________
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Figure 1.6
Sunlight
Heat
When energy is used
to do work, some
energy is converted to
thermal energy, which
is lost as heat.
Producers absorb light
energy and transform it into
chemical energy.
An animal’s muscle
cells convert
chemical energy
from food to kinetic
energy, the energy
of motion.
Chemical
energy
Chemical energy in
food is transferred
from plants to
consumers.
(a) Energy flow from sunlight to
producers to consumers
(b) Using energy to do work
A plant’s cells use
chemical energy to do
work such as growing
new leaves.
Theme: Structure and Function Are
Correlated at All Levels of Biological
Organization
• ___________ and ___________ of living organisms are
closely related
– A leaf is thin and flat, maximizing the capture of light
by chloroplasts
– A bird’s wing is adapted to flight
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Theme: The Cell Is an Organism’s Basic
Unit of Structure and Function
• Cell –
• All cells:
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Cell Types
• Eukaryotic cell
• Prokaryotic cell
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Theme: Life is Based on Heritable
Information in the Form of DNA
• _______________ are condensed DNA
(deoxyribonucleic acid) making up a cell’s genetic
material
• DNA makes up __________
• Genes:
• Basis of all reproduction, growth, and repair of
multicellular organisms is _______________
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Figure 1.9
25 m
DNA Structure and Function
• Each chromosome has one long DNA molecule with
hundreds or thousands of genes
• Genes encode information for building ____________
• DNA is inherited by offspring from their parents
• DNA controls the ________________ and ____________
of organisms
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Figure 1.10
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 ______________
• Made of building
blocks called
___________,
nicknamed A, G, C,
and T
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• Genes control protein production indirectly
DNA
RNA
____________
• Gene expression:
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Protein
_____________
Genomics: Large-Scale Analysis of DNA
Sequences
• Genome – The human genome as well as other organisms have been
sequenced using DNA-sequencing machines
• Genomics is the study of sets of genes
________________________
Figure 1.12
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Theme: Feedback Mechanisms Regulate
Biological Systems
• Feedback mechanisms allow biological processes to
________________
• Negative feedback –
• Positive feedback –
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Figure 1.13
Negative
feedback
A
Enzyme 1
Examples:
-
B
Excess D
blocks a step.
D
D
Enzyme 2
D
C
Enzyme 3
D
(a) Negative feedback
W
Enzyme 4
Positive
feedback 
X
Enzyme 5
Examples:
-
Excess Z
stimulates a
step.
Z
Y
Z
Z
Enzyme 6
Z
(b) Positive feedback
Evolution, the Overarching Theme of
Biology
• Evolution is the theme that makes sense of everything we know
about biology. It explains both the unity and diversity of living
organisms
– Organisms are modified descendants of common ancestors
– Similar traits among organisms are explained by descent from
common ancestors
– Differences among organisms are explained by the accumulation of
heritable changes
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Diversity of Life
• 1.8 million species have been identified
–
–
–
–
–
–
100,000 Fungi
290,000 Plants
52,000 Vertebrates
1,000,000 Insects
250,000 Protists
Billions of Bacteria
• 1,000’s of new species are identified each year
• Totals are predicted between 10-100 million
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Grouping Species: The Basic Idea
• Taxonomy –
• _________________ (1707-1778) – Father of Modern Taxonomy,
born in Sweden
– Now called _____________________
– Groupings and principles behind groupings have been significantly changed due
to new understanding of Biology (DNA, Microscopes, etc.)
Table of Animal Kingdom (1735)
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Linnaeus 1775
1. D
2. K
3. P
4. C
5. O
6. F
7. G
8. S
Three Domains of Life
• Archaea
• Bacteria
• Eukarya
– All eukaryotic organisms
– 4 Kingdoms of Eukarya, all widely varied
• ___________ (multicellular)
– Produce their own food through photosynthesis
• ___________ (single-celled to multicellular)
– Absorb nutrients from surroundings
• ___________
– Obtain nutrients through digestion
• ___________
– Photosynthesis, nutrient absorption, digestion
Figure 1.15
2 m
(b) Domain Archaea
2 m
(a) Domain Bacteria
(c) Domain Eukarya
Kingdom Animalia
100 m
Kingdom Plantae
Protists
Kingdom Fungi
Figure 1.14
Species Genus Family
Order
Class
Phylum Kingdom Domain
Ursus americanus
(American black bear)
Ursus
Ursidae
American Black
Bear
Carnivora
Domain: Eukarya
Kingdom: Animalia
Phylum: Chordata
Mammalia
Class:
Mammalia
Order:
Carnivora
Family:
Ursidae
Chordata
Genus:
Ursus
Species: Ursus americanus
Species name includes Genus
and species in either format:
Genus species or Genus
species
Animalia
Eukarya
Unity in the Diversity of Life
• Despite diversity, life has extreme unity at all levels of
hierarchy
– DNA, Skeletons, Tissue Organization, Cell Structure
Skeletal Muscle
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Charles Darwin and the Theory of
Natural Selection
•
Charles Darwin published: On
the Origin of Species by Means
of Natural Selection in 1859
• 2 Main Points:
1. ___________________
___________________
•
• Darwin’s 3 Observations:
1.
_________________________
2.
_________________________
3.
_________________________
Current species arose
from
a succession of
ancestors
2. ___________________
•
Mechanism for Descent
with modification
Orchid Flowers
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Fossils
Charles Darwin
• Darwin inferred that:
– Individuals ______________ to their environment
survive
– Individuals in a population will have the
________________
• Evolution occurs as the ________________________of
individuals
• Environment selects desirable traits (_______________)
• Natural selection leads to _________________
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• Evolution occurs due to unequal reproductive
success
– Individuals with desirable traits rerpoduce and pass those
traits on
• Environment selects desirable traits (Natural
Selection
The Tree of Life, Descent with
Modification
• “Unity in diversity” arises from “_____________________”
– ________________- forelimb of the bat, human, and horse and
the whale flipper all share a common skeletal architecture
•
Fossils provide additional evidence of anatomical unity from descent with
modification
• Darwin proposed natural selection could cause an ancestral species
to give rise to two or more _______________________
– For example, the finch species of the Galápagos Islands are
descended from a common ancestor
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Insect-eaters
Green warbler finch
Certhidea olivacea
Gray warbler finch
Certhidea fusca
Bud-eater
Seed-eater
COMMON
ANCESTOR
Warbler finches
Figure 1.22
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
Cactus-flowereaters
Seed-eaters
Ground finches
Darwin’s
Galapagos
Finches
Small tree finch
Camarhynchus parvulus
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
How do we do Science? Scientific
Method
1.
2.
3.
4.
5.
6.
7.
8.
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• Science –
• Inquiry –
Observation
Question
Hypothesis
-Observe and record data
-Qualitative
-Quantitative
-Question about
observations
-Proposed answer
to a testable
question
Results (Data)
Experiment
-Data collected from
experiment
-Tests hypothesis
-Repeatable
-Hypothesis cannot be
proven
Conclusion 1:
-Data support hypothesis
Conclusion 2:
-Data does not
support hypothesis
Publish results
-Share information with
scientific community
Types of Data
• Data are recorded ______________ or items of
information
– Qualitative data –
• Ex. Coastal Redwoods grow on the western coast of California
– Quantitative data • Ex. The current tallest Coastal Redwood is 379.3 ft.
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Forming and Testing Hypotheses
• Hypothesis –
– Questions are based on observations or inductive reasoning
• ___________________draws conclusions through the logical process
of induction
– Hypotheses lead to predictions that are ___________
– Hypotheses must also be ____________
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Figure 1.24a
Observations
Question
Hypothesis #1:
Dead batteries
Hypothesis #2:
Burnt-out bulb
Figure 1.24b
Hypothesis #1:
Dead batteries
Hypothesis #2:
Burnt-out bulb
Prediction:
Replacing batteries
will fix problem
Prediction:
Replacing bulb
will fix problem
Test of prediction
Test of prediction
Test falsifies hypothesis
Test does not falsify hypothesis
Deductive Reasoning and Hypothesis Testing
• Deductive reasoning
– If organisms are made of cells (premise 1), and humans are organisms (premise
2), then humans are composed of cells (deductive prediction)
• There are often _____________ alternative hypotheses
• Failure to falsify a hypothesis ___________ prove that hypothesis
– Ex. Replace your flashlight bulb, and it now works; this supports the
hypothesis that your bulb was burnt out, but does not prove it (perhaps
the first bulb was inserted incorrectly)
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A Case Study in Scientific Inquiry:
Investigating Mimicry in Snake Populations
•
Observation
– Many poisonous animals are brightly colored (warning coloration)
– Some animals appear to mimic this pattern w/o being poisonous
– Predators rarely attack coral snakes, not trial and error, natural selection increased
frequency of predators that avoid that coloration
•
Question
– What is the function of mimicry?
•
Hypothesis
– Deception is an adaptation that lowers a harmless animal’s risk of being eaten
because it’s mistaken for a poisonous animal
•
Experiment
– Tested in 2001 with the Scarlet Kingsnake and the Eastern Coral Snake
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• Both species live in the Carolinas, but the kingsnake is also found in
regions without venomous coral snakes
• If predators inherit an avoidance of the coral snake’s coloration, then
the colorful kingsnake will be attacked less often in the regions where
coral snakes are present
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Field Experiments with Artificial Snakes
• To test this mimicry hypothesis, researchers made hundreds of artificial
snakes:
– An experimental group resembling kingsnakes
– A control group resembling plain brown snakes
• Equal numbers of both types were placed at field sites, including areas
without poisonous coral snakes
(a) Artificial kingsnake
(b) Brown artificial snake that has been attacked
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• After four weeks, the scientists retrieved the artificial snakes and
counted bite or claw marks
• The data fit the predictions of the mimicry hypothesis: the ringed
snakes were attacked less frequently in the geographic region where
coral snakes were found
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Experimental Controls and Repeatability
•
Controlled Experiment –
•
Experimental Variable – factor in experiment that can
_________________(the effect of coloration on the behavior of
predators)
– Only one variable should differ between control group and experimental
group
•
Experimental Groups –
•
Control Groups –
•
Observations and experimental results must be _______________
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Theories in Science
• Theory
– _____________ in scope than a hypothesis
– General, and can lead to ______________________
– Supported by a _________________________ in comparison to a
hypothesis
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