Unit 3 … Chapter 9.1
Classification
Source:
McDougal-Littell Science
Grade 6
Ch. 9 - Classification
4 Unifying Life Science Principles:
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All living things share common characteristics.
All living things share common needs.
Living things meet their needs interaction with
the environment.
The types and numbers of living things
changes over time.
Unit 3 - Chapter 9
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9.1 Scientists develop systems for
classifying living things.
9.2 Biologists use seven levels of
classification.
9.3 Classification systems change as
scientists learn more.
9.1 – There Is A System
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Scientists have developed a system for
classifying the great diversity of living things.
Scientists classify millions of species.
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Used to use appearances & behavior
Now use binomial nomenclature
Taxonomists study biological
relationships (similarities/differences).
9.1 Millions of Species …
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Classification is the scientific process of
arranging organisms into groups based
on similarities.
Taxonomy is the science of naming and
classifying organisms.
A good systems eliminates confusion,
uses similarities, differences, and DNA.
9.1 Biological Relationships
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Scientists compare physical traits and
evolutionary ancestry to determine how
species are related.
Fossils help scientists determine the
evolutionary history of a species.
DNA evidence can support physical
evidence in determining
relationships.
Unit 3 … Chapter 9.2
Classification
Source:
McDougal-Littell Science
Grade 6
9.2 Classification Has 7 Levels
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Linnaeus named about 4,000 species
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Organisms can be classified into 7 levels
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Dichotomous keys and field guides help
people identify organisms
9.2 Carolus Linnaeus (1700) …
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Named about 4,000 species &
Developed the system of binomial
nomenclature
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Uses 2 names for each species
First part of name = genus
Second part of name = species
Most names are in Latin
9.2 Classification Hierarchy
Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Carnivora
Family
Felidae
Genus
Felis
Species
catus
9.2 Taxonomy
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Taxonomy – Greek root “taxis” means
“arrangement”
Taxonomists compare similarities and
differences among a variety of traits or
characteristics. They use …
1.
physical evidence
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2.
such as fur, bones, teeth, color, size,
weight, how they obtain energy, and
genetic evidence
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(DNA/RNA)
9.2 Naming Species
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A genus is a group of species that have
similar characteristics.
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(Ex. Genus Ursus = bears)
Binomial Nomenclature: A system for
naming species developed by Linnaeus.
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Binomial = two names
Genus + Species (Ex. Ursus arctos = grizzly
& Ursus maritimus = polar bear)
9.2 Dichotomous Keys & Field
Guides Are Helpful Tools
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A dichotomous key is a tool to help
scientists identify an organism by asking a
series of paired questions about physical
traits. (The answer to each question either
identifies the organism or leads to the next
question in the series.)
Field guides use paintings or photos of
organisms and include scientific names,
range maps, and descriptions.
Dichotomous Key
Leaf
qLeaf has 3 or
more main veins
xLeaf has
1 main vein
qLeaf has no
teeth, no lobes
P
Paired Questions
only 1 answer
xLeaf has
Teeth or lobes
qLeaf
Is lobed
qLeaf has veins
that end in teeth
P
xLeaf is
not lobed
P
xLeaf has more P
teeth than side veins
Apple Leaf
P
Unit 3 … Chapter 9.3
Classification
Source:
McDougal-Littell Science
Grade 6
9.3 Classification Systems
Change Over Time
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Taxonomy changes as scientists make
new discoveries.
The two most familiar kingdoms are
plants and animals
Other organisms make up the four other
kingdoms (fungi, protista, bacteria, archaea)
Species and environments change.
9.3 Three (3) Domains
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Microscopes & other technology
advances led to discovery of three
fundamentally different types of cells.
Scientists classify them based on:
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Cell type (nucleus vs. no nucleus)
Cell number
How they obtain energy
9.3 Classification Systems
Change Over Time
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Taxonomy changes as scientists make
discoveries or find new information
about an organism’s evolutionary
history.
There are 3 Domains & 6 Kingdoms
The Domain Eukarya is made up of 4
Kingdoms: Anamalia, Plantae, Fungi, &
Protista
MATTER
9.3 Classification
Living
Non-Living
3 Domains
Prokaryotic
no nucleus-1 celled
I.
Archaea
II.
Bacteria
6 Kingdoms
6.Archaea
5.Bacteria
Eukaryotic
nucleus
Periodic Table
Solid
Liquid
Gas
Plasma
III.
Eukarya
1.Anamalia
2. Plantae
3. Fungi
4. Protista
1.
2.
3.
4.
5.
6.
7.
Kingdom
Phylum
Class
Order
Family
Genus
Species
9.3 Plants & Animals
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Plant & animal cells share many
characteristics
Plants differ in that they have a cell wall,
chloroplasts, & chlorophyll
Plants are producers (sugar, oxygen)
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250,000 species
Animals are consumers
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1 million species; 90% insects
9.3 Other Kingdoms
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Protista – 1-celled or multi-cellular
(Cannot be plant, animal, or fungus)
Fungi include mushrooms, yeasts, molds
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Obtain energy by breaking down dead or
decaying material (from environment)
Archaea & Bacteria were once classified as
fungi, but differences lead to separate
kingdom classification. (Note: domain &
kingdom names are the same for these 2.)