Introduction: Themes in
the Study of Life
PowerPoint® Lecture Presentations for
Biology
Eighth Edition
Neil Campbell and Jane Reece
Lectures by Chris Romero, updated by Erin Barley with contributions from Joan Sharp Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Overview: Inquiring About the World of Life
• Evolution
• Biology
Response
Evolutionary to the
environment
adaptation
• Life is recognized by what
livings things do
• Biology consists of more
than memorizing factual
details
Order
• Themes help organize
biological information
Reproduction
Regulation/
Homeostasis
Energy
processing
Growth and
development
Theme: New Properties Emerge at Each Level in
the Biological Hierarchy
The biosphere
Cells
Biomes
Organs and
organ systems
Ecosystems
Cell
Organelles
Communities
Atoms
Tissues
Molecules
Populations
Organisms
Emergent Properties
• Emergent Properties: result from arrangement
and interaction of parts within a system
– EXAMPLES?
The Power and Limitations of Reductionism
• Reductionism: breakdown of complex systems
to simpler components more manageable to
study
– Example: the molecular structure of DNA
• Understanding biology balances reductionism
with the study of emergent properties
– Example: new understanding comes from
studying the interactions of DNA with other
molecules
Systems Biology
• System: combination of components that
function together
• Systems biology: constructs models for the
dynamic behavior of whole biological systems
• Systems approach poses questions such as:
– How does a drug for blood pressure affect other
organs?
– How does increasing CO2 alter the biosphere?
Theme: Organisms Interact with Environments,
Exchanging Matter and Energy
• Every organism interacts with its environment,
including abiotic factors and other organisms
• Both organisms and their environments are
affected by the interactions between them
– 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
Ecosystem Dynamics
• Energy exchange
between an organism
and its environment
often involves energy
transformations
• Dynamics of an
ecosystem include 2
major processes:
– Cycling of nutrients,
materials acquired
by plants eventually
return to the soil
– Flow of energy from
sunlight to
producers to
consumers, then to
heat
Sunlight
Ecosystem
Cycling
of
chemical
nutrients
Producers
(plants and other
photosynthetic
organisms)
Heat
Chemical energy
Consumers
(such as animals)
Heat
Theme: Structure and Function are Correlated at
all Levels of Biological Organization
• Structure and function of organisms are closely related
– Example: a leaf is thin and flat, maximizing capture of
light by chloroplasts
(b) Bones
(a) Wings
Infoldings of
membrane
(c) Neurons
Mitochondrion
100 µm
0.5 µm
(d) Mitochondria
Theme: Cells are Organism’s Basic Units of
Structure and Function
• Cell is 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
• Ability of cells to divide is basis of all reproduction, growth, and repair of multicellular organisms
• Eukaryotic cell:
Eukaryotic cell
has membraneenclosed
organelles; largest Membrane
is usually the
Cytoplasm
nucleus
• Prokaryotic cell:
simpler; usually
smaller; does not
contain nucleus or
other membraneenclosed
organelles
• Bacteria and
Archaea are
prokaryotic; plants,
animals, and fungi
Organelles
are eukaryotic
Nucleus (contains DNA)
Prokaryotic cell
DNA
(no nucleus)
Membrane
Theme: The Continuity of Life is Based on
Heritable Information in the Form of DNA
•
Chromosomes contain most of cell’s genetic
material...
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