Download CHAPTER ONE (continued) INTRODUCTION to LIFE SCIENCE

CHAPTER ONE
(continued again)
Natural Hierarchy
&
Unity and Diversity of Life
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The Hierarchy of Life
Biosphere
Ecosystem
Community
Population
Organism (Multicellular)
Organ
Tissue
Cell
Organelle
Molecule
Atom
Subatomic Particle
Biosphere
Ecosystem
Florida coast
Community
All organisms on
the Florida coast
Population
Group of brown
pelicans
Organism
Brown pelican
Spinal cord
Nerve
Organ system
Nervous system
Brain
Organ
Brain
Tissue
Nervous tissue
Cell
Nerve cell
Atom
Nucleus
Organelle
Nucleus
Molecule
DNA
In life’s hierarchy of organization, new properties
emerge at each level
• The upper tier is a global perspective of life
– Biosphere—all the environments on Earth that
support life
– Ecosystem—all the organisms living in a particular
area
– Community—the array of organisms living in a
particular ecosystem
– Population—all the individuals of a species within a
specific area
Copyright © 2009 Pearson Education, Inc.
In life’s hierarchy of organization, new properties
emerge at each level
• The middle tier is characterized by the organism,
an individual living thing, which is composed of
– Organ systems—have specific functions; are
composed of organs
– Organs—provide specific functions for the organism
– Tissues—made of groups of similar cells
Copyright © 2009 Pearson Education, Inc.
In life’s hierarchy of organization, new properties
emerge at each level
• Life emerges at the level of the cell, the lower
tier, which is composed of
– Molecules—clusters of atoms
– Organelles—membrane-bound structures with
specific functions
– Cells—living entities distinguished from their
environment by a membrane
Copyright © 2009 Pearson Education, Inc.
Unity of Life
• Highly Organized (Cellular Structure)
• Able to Acquire and Use Energy (Metabolism)
• Able to Grow and Reproduce
Diversity of Life
• Highly Organized (Cellular Structure)
– Prokaryotic or Eukaryotic Cells
– Single-celled or Multicellular
• Able to Acquire and Use Energy (Metabolism)
– Producer
– Consumer
– Decomposer
• Able to Grow and Reproduce
– Asexual or Sexual
DIVERSITY of LIFE
• Taxonomy: Formal system of naming organisms
– Binomial: Genus and Species
– Based on Phylogeny: Evolutionary Relationships
– Three Domains:
• Archaea
• Bacteria
• Eukarya: Divided up into Kingdoms:
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Protists (actually multiple kingdoms)
Fungi
Plants
Animals
The diversity of life can be arranged into three domains
• The three domains (groups) of life
– Bacteria—prokaryotic, and most are unicellular and
microscopic
– Archaea—like bacteria, are prokaryotic, and most
are unicellular and microscopic
– Eukarya—are eukaryotic (their cells contain a
nucleus and organelle); some are unicellular and
some are multicellular
Copyright © 2009 Pearson Education, Inc.
Cells are the structural and functional units of life
• Two distinct groups of cells exist
– Prokaryotic cells
– Simple and small
– No nucleus or organelles separated by membranes
– Bacteria and Archaea are prokaryotic
– Eukaryotic cells
– Larger and more complex
– Possess a nucleus
– Possess organelles separated by membranes
– Plants, animals, protists, and fungi are eukaryotic
Copyright © 2009 Pearson Education, Inc.
Prokaryotic cell
Eukaryotic cell
DNA
(no nucleus)
Membrane
Nucleus
(contains DNA)
Organelles
Kingdoms
Eukarya: Divided up into Kingdoms:
–Protists
– Most unicellular; Consumers and Producers
–Fungi
– Most multicellular; Decomposers
–Plants
– Multicellular; Producers
–Animals
– Multicellular; Consumers; Cells lack cell walls
Domain Eukarya
Domain Bacteria
Bacteria (multiple kingdoms)
Protists (multiple kingdoms)
Kingdom Plantae
Domain Archaea
Archaea (multiple kingdoms)
Kingdom Fungi
Kingdom Animalia