chapter 1
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CHAPTER 1 INTRODUCTION: TEN THEMES IN THE STUDY OF LIFE
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Biology, the study of life, is rooted in the human spirit. Biology has been pursued for centuries by men of God as they
attempted to learn about God as they studied nature—called:
Natural Theology
Introduction
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Who were these “natural theologians?”
Blaise Pascal (1623-1662)
Jansenist, a group of Calvinist French Catholic who emphasized salvation through God’s love and grace
Roger Bacon (1214-1294)
English Monk used glass to magnify organisms
Louis Pasteur
Experiments that demonstrated the cell theory—“all living things are made of cells and all cells come form pre-existing cells”
Lord Kelvin
Opponent of Darwin Father of “Energetics”
Carolus Linnaeus 1701-1778
Father of Modern taxonomy Accepted the Biblical account of
creations Concluded that created kinds never
alter enough to form new and different kinds
The list goes on:
Michael FarradayJohann KeplerIsaac NewtonGregor MendelLeonardo da VinciJoseph Lister
Biologists explore life form a global to a microscopic scale
Life’s basic characteristic is a high degree of order.
Each level of biological organization has emergent properties
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Fig. 1.2(1) Fig. 1.2(2)
Biological organization is based on a hierarchy of structural levels, each building on the levels below. At the lowest level are atoms that are
ordered into complex biological molecules.
Many molecules are arranged into minute structures called organelles, which are the components of cells.
Cells are the subunits of organisms, the units of life.
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Fig. 1.2(3)
Some organisms consist of a single cell, others are multicellular aggregates of specialized cells.
What is the upward hierarchy of biological complexity?
Cells Tissues Organs Organ systems Organisms Populations Communities Ecosystems Biomes
Novel properties emerge at each step upward in the biological hierarchy.
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
These emergent properties result from interactions between components.A cell is certainly much more than a bag of molecules.
This theme of emergent properties accents the importance of structural arrangement.
The emergent properties of life are not supernatural, but simply reflect a hierarchy of structural organization.
Life resists a simple, one-sentence definition, yet we can recognize life by what living things do.
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Fig. 1.3
Whether multicellular or unicellular, all organisms must accomplish the same functions:
Growth and development
Metabolism
Regulation
Respond to environment
Figure 1.3bx Reproduction
Reproduction
Living things exhibit order
Figure 1.3 Some properties of life
Figure 1.3ax Order
The complex organization of life presents a dilemma to scientists seeking to understand biological processes.
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
We cannot fully explain a higher level of organization by breaking down to its parts.
At the same time, it is futile to try to analyze something as complex as an organism or cell without taking it apart.
Reductionism, reducing complex systems to simpler components, is a powerful strategy in biology.
Reductionism is balanced by the longer-range objective of understanding emergent properties.
Science is a process
Science seeks natural causes for natural phenomena.
The scope of science is limited to the study of structures and processes that we can observe and measure, either directly or indirectly.
Verifiable observations and measurements are the data of discovery science.
In some cases the observations entail a planned detailed dissection and description of a biological phenomenon, like the human genome.
In other cases, curious and observant people make totally serendipitous discoveries.
In 1928, Alexander Fleming accidentally discovered the antibacterial properties of Pencillium when this fungus contaminated some of his bacterial cultures.
Discovery science can lead to important conclusions via inductive reasoning. An inductive conclusion is a generalizationthat summarizes many concurrent observations.
Organizing Species
Linnaeus developed our system of organizing using 7 taxons
KingdomPhylum Class Order Family Genus species
The scientific name is made of the Genus and species name (hence binomial nomenclature)
Examples:Homo sapiensDrosophila melanogasterSalmonella typhimurium
Linnaeus used 2 groups
Plant Kingdom Animal Kingdom
Whitaker used 5 kingdoms
Monerans Plants Animals Fungi Protists
Scientists have now added a new taxon, called a “domain”
Current system uses 3 domains:Bacteria Archaea Eukarya
Both are prokaryotic
Monerans are Prokaryotic
Smaller than eukaryotes No membrane bound organelles DNA is not contained in a nucleus
Plants, animals, fungi and protists are eukaryotes
Larger Have membrane bound nucleus
containing DNA Have membrane bound organelles
that compartmentalize cells
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