Download 1 Chapter 18 - Blair Community Schools

Chapter 18: Classification
Dichotomous Key
1.
2.
3.
4.
A way to identify unknown organisms
Contains major characteristics of groups of organisms
Pairs of CONTRASTING descriptions
After each description key either directs use to another pair of
descriptions or identifies an object
Section 1: The Importance of Classification
Taxonomy:
Genus:
Binominal Nomenclature: a system for giving each organism a twoword scientific name that consists of the genus name followed by the
species name
I. The Need for Systems
A. About _______ million species have been named and described by
scientists
B.
C. Practice of naming and classifying organisms is taxonomy
D.
E. Systems attempt to provide consistent ways to name and
categorize organisms
F.
1. May be confusing because common names are different in
different places
2.
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G. Biologists group organisms into large categories
1. Then smaller, more specific categories
a.
II. Scientific Nomenclature
A. Various naming systems were invented in the early days of
European biology
1.
2. Names for taxa were inconsistent between these systems
3. The only consistent taxon was genus
a.
B. Carlos Linnaeus
1.
2.
3. Developed simpler and more consistent system
4. Two-word naming system called
5. Genus name and a single descriptive word for each species
6.
7.
C. Naming Rules
1.
2. All scientific names are made up of two Latin or Latin-like terms
3.
2
4. The second term is called the species identifier, and is often
descriptive
5. When you write the scientific name, the genus name should be
capitalized and the species identifier should be lowercase
6.
7. Example
a. Apis mellifera is the European honeybee
1) The term mellifera derives from the Latin word for honey
III. The Linnaean System
A. Devised a system to classify all plants and animals that were known
B. Organisms grouped at successive levels of the hierarchy based on
similarities in form and structure
C. Eight basic levels of modern classification
1.
2.
3.
4.
5.
6.
7.
8.
D. Classification of Man
1. Domain
2. Kingdom
3. Phylum
3
4. Class
5. Order
6. Family
7. Genus
8. species
D. Each taxon is identified based on shared traits.
E. Similar species are grouped into a genus
1. Similar genera are grouped into a family
2. And so on up to the level of domain
F. Domain
1.
2. Recognizes most basic differences among cell types
3. All living things grouped into one of three domains
G. Kingdom
1.
H. Phylum
1.
I. Class
1.
J. Order
1.
K. Family
1.
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L. Genus (plural, genera)
1.
M. species
1. Subgroup within Genus
2.
3.
4. Defined as a unique group of organisms united by heredity or
the ability to interbreed
5. Scientists tend to define species based on unique features
6. Example
1. Homo sapiens
a.
b.
Section 2: Modern Systematics
Phylogenetic Tree: shows the evolutionary relationships among
organisms
I. Evolutionary Relationships
A. Phylogenetic Tree:
1.
2. Fossil Record Used
3. Comparative to family members
4. Spirochetes are most closely related to what organisms?
5. Name two organisms that are distantly related
6.
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7.
II. Physical Structures
A. Linnaeus based his classification on
B. Moderns scientists base classification on
III. Problems in Classification
A. As new evidence is discovered and new research is done scientists
are having to reclassify organisms
Section 3: Kingdoms and Domains
Bacteria: extremely small, single-celled organisms that usually have a
cell wall and that usually reproduce by cell division: members of the
domain Bacterial
Archaea:
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Eukaryote: an organism made up of cells that have a nucleus enclosed
by a membrane, multiple chromosomes, and a mitotic cycle;
members of the domain Eukarya
I. Updating Classification Systems
A. When Linnaeus created his system he recognized two kingdoms:
1.
2.
B. Biologists have added complexity and detail to classification
systems as they have learned more
1.
2.
a.
b. Microscopes allowed scientists to study sponge cells
c. Scientists learned that sponge cells are much more like animal
cells, so today sponges are classified as animals
C.
D. Then noticed differences between prokaryotic and eukaryotic cells
1. Scientists created Kingdom Monera for prokaryotes
E. By the 1950s, Kingdoms Monera, Protista, Fungi, Plantae, and
Animalia were used
F. In the 1990s, genetic data suggested two major groups of
prokaryotes
1. Kingdom Monera split into Kingdoms
a.
b.
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II. The Three-Domain System
A. Divide all organisms into three domains
1.
2.
3.
B. Major taxa are defined by major characteristics, including
1. Cell Type
a.
b.
2. Cell Walls
a.
b.
3. Body Type
a.
b.
4. Nutrition
a.
b.
5. Related groups of organisms have similar
a.
b.
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C. Bacteria
1.
2.
3.
4.
5.
Strong exterior walls and a unique genetic system
Same kind of cell membrane lipid as most eukaryotes do
All bacteria are similar in structure, no internal compartments
Classified according to
a.
b. Nature of their cell wall
c. Their type of metabolism
d.
6. Most abundant organisms on Earth
7.
D. Archea
1.
2. Unique genetic system
a. Share some similarities with those of eukaryotes that they do
not share with those of prokaryotes
3. Scientists think that archea evolved in a separate lineage from
bacteria early in Earth’s history
4. Scientists also believe that some archea eventually gave rise to
eukaryotes
5. First found in extreme environments
a.
b.
c.
d. These archaea are called extremophiles.
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e.
E. Eukarya is made up of Kingdoms
1.
2.
3.
4.
5.
6. Cells have a complex inner structure that enabled cells to
become larger than the earliest cells
7. Complex inner structure enabled the evolution of multicellular
organisms
8. True multicellularity and sexual reproduction
9. Major groups of eukaryotes are defined by
1.
2.
3.
F. Plantae
1.
a. The process that makes food, photosynthesis, occurs in
chloroplasts
2.
3. More than 350,000 known species of plants exist
G. Animalia
1.
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2. Their bodies may be simple collections of cells or complex
networks of organ systems
3.
4. More than 1 million known species of animals exist
H. Fungi
1.
2.
3. More than 70,000 known species of fungi exist
I. Protista
1.
2. Any eukaryote that is not a plant, animal, or fungi can be called
a protist
3. Did not descend from a single common ancestor
4. Biologists recognize four major groups of protists:
a.
b.
c.
d.
5. Recently, biologists have proposed to replace Protista with
several new kingdoms
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Natural Selection Review
I. Define natural selection.
A.
B. List the four parts of natural selection
1.
2.
3.
4.
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Use the table below to answer questions the following questions.
Level
House
Cat
Animalia Animalia Animalia Animalia
Octopus
Anteater
Animalia
Animalia
Chordat
a
Mammal
ia
Carnivor
a
Canidae
Chordata
Molluska
Chordata
Mammalia
Genus
Canis
Canis
Hominid
ae
Homo
Mammali
a
Carnivor
a
Felidae
Cephalopo
da
Octopoda
Family
Chordat
a
Mammal
ia
Carnivor
a
Canidae
Octopodid
ae
Octopus
Specie
s
familiari
s
lupus
sapiens
Myrmecophagi
dae
Myramecophag
a
tridactyla
Kingdo
m
Phylu
m
Class
Order
Dog
Wolf
Human
Chordat
a
Mammal
ia
Primate
Felis
domestic
us
vulgaris
Edentata
a. Which organisms on the table are most closely related?
b. Which level of classification is your answer based on?
c. Which organism on the table is the most distantly related to the
others?
d. Which level of classification is your answer based on?
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