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BIOLOGYCONCEPTS & 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 1Introduction:
The Scientific Study of Life
Modules 1.1 – 1.3
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• The lives of gray-headed flying foxes are closely entwined with the lives of the eucalyptus trees that form their habitat
– Eucalyptus trees provide food and roosting sites for the flying foxes
– Flying foxes aid in eucalyptus pollinationand help disperse the resulting seeds
Life in the Trees
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Flying foxes are becoming an endangered species, partly because of habitat destruction
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Biology is the scientific study of life
• Interactions between different kinds of organisms affect the lives of all
– Recall the example of flying foxes and eucalyptus trees
THE SCOPE OF BIOLOGY
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• 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
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• 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 LEVELEucalyptus forest
COMMUNITY LEVELAll organisms ineucalyptus forest
POPULATION LEVELGroup of flying foxes
ORGANISM LEVELFlying fox
ORGAN SYSTEM LEVELNervous system
ORGAN LEVELBrain
Brain Spinal cord
Nerve
TISSUE LEVELNervous
tissue
CELLULAR LEVELNerve cell
MOLECULAR LEVELMolecule of DNA
Figure 1.1
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Organisms are made up of:
– organ systems
– organs
– tissues
– cells
– molecules
ECOSYSTEM LEVELEucalyptus forest
COMMUNITY LEVELAll organisms ineucalyptus forest
POPULATION LEVELGroup of flying foxes
ORGANISM LEVELFlying fox
ORGAN SYSTEM LEVELNervous system
ORGAN LEVELBrain
Brain Spinal cord
Nerve
TISSUE LEVELNervous
tissue
CELLULAR LEVELNerve cell
MOLECULAR LEVELMolecule of DNA
Figure 1.1
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• 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
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• In hypothesis-driven science, scientists use the “scientific method”
– They propose a hypothesis
– They make deductions leading to predictions
– They then test the hypothesis by seeing if the predictions come true
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• 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
additionalobservation
Test does notsupport hypothesis; revise hypothesis or
pose new one
Test supports hypothesis; make
additional predictions and test them
Figure 1.3A
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• 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
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Experiments designed to test hypotheses must be controlled experiments
• Control groups must be tested along with experimental groups for the meaning of the results to be clear
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Case study: spider mimicry
Po
un
ce
ra
te (
% o
f tr
ials
in
w
hic
h s
pid
er
jum
pe
d o
n f
ly)
Control group(untreated flies)
Experimental group(wing markings masked)
Figure 1.3C
Figure 1.3D
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Another test of the spider mimic hypothesis: wing transplants
Nu
mb
er o
f st
alk
and
atta
ck r
esp
on
ses
by
spid
ers
Wingmarkings
Normalspidermimic
Figure 1.3E
Wingwaving
Mimic withmimic wing transplant
Controls Experimentals
Mimic withhousefly
wing transplant
Housefly with
mimic wing transplant
Normalhousefly