Unit 1(ch1) ppt.ppt

BIOLOGY
CONCEPTS & CONNECTIONS
Fourth Edition
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Neil A. Campbell • Jane B. Reece • Lawrence G. Mitchell • Martha R. Taylor
From PowerPoint® Lectures for Biology: Concepts & Connections
CHAPTER 1
Introduction:
The Scientific Study of Life
Modules 1.1 – 1.3

• Biology is the scientific study of life
• Interactions between different kinds of
organisms affect the lives of all
THE SCOPE OF BIOLOGY

• A structural hierarchy of life, from molecules to
ecosystems, defines the scope of biology
• An ecosystem consists of:
– all organisms living in a particular area
– all nonliving physical components of the
environment that affect the organisms
(soil, water)
1.1 Life’s levels of organization define the scope of
biology

• At the top of life’s
hierarchy is the
ecosystem
• Ecosystems include:
– all the organisms
in an area, which
make up a
community
– interbreeding
organisms of the
same species, a
population
ECOSYSTEM LEVEL
Eucalyptus forest
COMMUNITY LEVEL
All organisms in
eucalyptus forest
POPULATION LEVEL
Group of flying foxes
ORGANISM LEVEL
Flying fox
ORGAN SYSTEM LEVEL
Nervous system
ORGAN LEVEL
Brain
Brain
Spinal cord
Nerve
TISSUE LEVEL
Nervous
tissue
CELLULAR LEVEL
Nerve cell
MOLECULAR LEVEL
Molecule of DNA
Figure 1.1

• Organisms are
made up of:
– organ systems
– organs
– tissues
– cells
– molecules
ECOSYSTEM LEVEL
Eucalyptus forest
COMMUNITY LEVEL
All organisms in
eucalyptus forest
POPULATION LEVEL
Group of flying foxes
ORGANISM LEVEL
Flying fox
ORGAN SYSTEM LEVEL
Nervous system
ORGAN LEVEL
Brain
Brain
Spinal cord
Nerve
TISSUE LEVEL
Nervous
tissue
CELLULAR LEVEL
Nerve cell
MOLECULAR LEVEL
Molecule of DNA
Figure 1.1

• In discovery science, scientists describe some
aspect of the world and use inductive reasoning
to draw general conclusions
– Example: scientists have
described how newborn
flying foxes cling to their
mother’s chest for the
first weeks of life
1.2 Scientists use two main approaches to learn
about nature
THE PROCESS OF SCIENCE
Figure 1.2

• In hypothesis-driven science, scientists use the
“scientific method”

• The main
steps of the
scientific
method
1.3 With the scientific method, we pose and test
hypotheses
Observation
Question
Hypothesis
Prediction
Test:
Experiment or
additional
observation
Test does not
support hypothesis;
revise hypothesis or
pose new one
Test supports
hypothesis; make
additional predictions
and test them
Figure 1.3A

Observation Skills
• Observe the following scene quietly for 30
seconds.

• Are there cars parked on the sides of the road?
• What color is the pickup truck driving in the
road?
• Any minivans around?
• What does the blue sign say?
• What's the speed limit?
• Are there any pedestrians on the road?

Eye Witness
• 1 witness, 1 investigator

• Deductive reasoning is used in testing
hypotheses
– If a hypothesis is
correct, and we test it,
then we can expect a
particular outcome
• Case study: flashlight
failure
Figure 1.3B

• Experiments designed to test hypotheses must
be controlled experiments
• Control groups must be tested along with
experimental groups for comparison

• Case study: spider mimicry
Pounce
rate
(%
of
trials
in
which
spider
jumped
on
fly)
Control group
(untreated flies)
Experimental group
(wing markings masked)
Figure 1.3C
Figure 1.3D

• Another test of the spider mimic hypothesis:
wing transplants
Number
of
stalk
and
attack
responses
by
spiders
Wing
markings
Normal
spider
mimic
Figure 1.3E
Wing
waving
Mimic with
mimic wing
transplant
Controls Experimentals
Mimic with
housefly
wing
transplant
Housefly
with
mimic wing
transplant
Normal
housefly

1.4 The diversity of life can be arranged into three
domains
EVOLUTION, UNITY, AND DIVERSITY

order of taxa in biology
• (Domain, Kingdom, Phylum, Class, Order, Fami
ly, Genus, Species)
– Dear King Philip Come Over For Good Soup

• Most classification schemes group organisms
into three domains:
– Domain Bacteria
• No nucleus
• 1 chromosome
Figure 1.4A, B
– Domain Archaea

– Domain Eukarya - cells have a membrane
bound nucleus and organelles
Figure 1.4C-F

• All organisms share a set of common features,
signs of unity in life’s vast diversity
– All are made of cells
– All have DNA as
their genetic
blueprint
1.5 Unity in diversity: All forms of life have
common features
Figure 1.5A

• DNA is made of chemical units called
nucleotides
• Each species has its own nucleotide sequence
Figure 1.5B

• The genetic information in DNA underlies all
of the features that distinguish life from nonlife
– Order and regulation
– Growth and development
– Use of energy from the environment
– Response to environmental stimuli
– Ability to reproduce
– Evolutionary change

• Charles Darwin is a central figure in biology
• He synthesized the theory of evolution by
natural selection
– A theory in science is a
comprehensive idea with
broad explanatory power
• Evolution is the core theme
of biology
1.6 Evolution explains the unity and diversity of
life
Figure 1.6A

• The theory of
natural selection
explains the
main mechanism
whereby all
species of
organisms
change, or evolve
Figure 1.6B
(1) Population with varied inherited traits
(2) Elimination of individuals with certain traits
(3) Reproduction of survivors

• Evolution happens when populations of
organisms with inherited variations are
exposed to environmental factors that favor the
success of some individuals over others
– Natural selection is the editing mechanism
– Evolution is based on adaptations
Figure 1.6C

• The theory of natural selection applies to all
levels in life’s hierarchy
• Video: #75 (natural selection CCR)
• http://www.youtube.com/watch?v=aTftyFboC_
M
• In an ecosystem, these interactions make up a
complex web of relationships
1.7 Living organisms and their environments form
interconnecting webs

• A web of
interactions
in a rain
forest
ecosystem
Figure 1.7A

• Plants, or plant products, are the ultimate
sources of food in an ecosystem
– This African sunbird is consuming nectar, a
plant product
Figure 1.7B

• Chemical nutrients cycle within an ecosystem’s
web
– Energy
flows in
and out
constantly
Figure 1.7C
Sun
Inflow
of
light
energy
Air Chemical
energy
Cycling
of
chemical
nutrients
Organisms
Soil
ECOSYSTEM
Loss
of
heat
energy

• Biology is connected to a great number of
important issues
– Environmental
problems and
solutions
– Genetic engineering
– Medicine
1.8 Connection: Biology is connected to our lives in
many ways
BIOLOGY AND EVERYDAY LIFE
Figure 1.8A

Observation
A farmer notices that his
neighbors wheat yields are
consistently higher than
his own.

Testable
Question
What causes the other
farmers fields to produce
more grain?

Possibilities
Farming Practices
Variety of Seed
Time of planting
Summer fallow
Fertilizing
Pesticides

Outside Factors
Less moisture due to
varying weather patterns
Poor Soil
Other Neighbors fields
holding pests

Hypothesis
The farmer thinks that it is
most likely the result of the
seed variety.

Prediction
If the farmer plants the
same seed variety as his
more successful neighbor,
then his yields will be
higher than with the old
variety.

Controlled
Experiment
Independent Variable –
The variable that will be
changed by the conductor
of the experiment.
The variety of wheat seed

Controlled
Experiment
Dependent Variable – The
variable that will be
measured to determine the
effect of the Independent
Variable.
The wheat yield

Controlled
Experiment
Controlled Variables – The variables
that may have an effect on the
dependent variable, but are not being
tested, so must remain the same.
Fertilizer, time of planting, seeding
rate, moisture, weather damage, etc.

Controlled
Experiment
Controlled Variables – The
variables that will not be allowed
to change. Any measured
difference will be due to the
effect of the Independent
Variable.
Fertilizer, Pesticide, Time of
Planting, Weather

Controlled
Experiment
Experimental Group- the group in
which the Independent variable is
changed.
Control Group- group in which the
independent variable is left
unchanged. Controls other possible
variables, used for comparison.

Controlled
Experiment
The farmer 10 separate strips
and alternately plants 5 strips
to his old variety and 5 to the
new variety.
The field is treated exactly
the same for each variety.

Results
The farmer carefully harvests
one variety and then the
other.
The new variety yields a total
of 2,017 bushels, while his
old variety yields 2,156
bushels.

Conclusions
The farmer decides that
the seed variety is not the
factor that causes his
neighbors yields to be
higher.

Start Over
The farmer thinks the next most
likely variable is fertilizer.
He repeats his experiment, this
time using only one seed variety,
while fertilizing one set of strips
and not fertilizing the other.

Results
The fertilized strips yield
2,562 bushels.
The unfertilized strips yield
1,985 bushels.

Conclusions
The farmer decides that the
fertilizer made a drastic
difference in yield and then
compared the cost of the
fertilizer with the yield increase.
He then fertilized all of his
cropland before planting.

(1.6)
Evolution explains
the Unity and
Diversity of Life

Sexual Selection
Gene Indicators
Preferential Mating
Individuals with “Good Gene”
indicators are selected more
for mating and pass on more
genes to the next generation.

Common Characteristics
of Living Things
Order – complex organization (cells)
Regulation – maintain internal
environment (Homeostasis)
Growth and Development
Utilize Energy
Respond to the environment
Reproduction
Evolution

Unit 1(ch1) ppt.ppt

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