Transcript Chapter 18- Classification

Chapter 18- Classification
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I. Finding order in Diversity
A. Why classify?
1. To study the diversity of life, biologists use
a classification system to name organisms
and group them in a logical manner.
2. Using taxonomy, scientists classify
organisms and assign each organism a
universally accepted name.
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B. Assigning Scientific Names
1. By the eighteen-century scientists were
finding out that calling organisms by their
common name was confusing.
2. Carolus Linnaeus developed a two-name
naming system called binomial nomenclature.
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3. Each species is assigned a two –
part scientific name.
4. Ex- Homo sapiens
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C. Linnaeu’s System of Classification
1. Linnaeus’s hierarchical system of
classification includes seven levels.
2. From the largest to the smallestkingdom, phylum, class, order, family,
genius and specie.
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King Philip Came Over For Good Spagetti
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II. Modern Evolutionary
Classificiation
A. Which similarities are most important?
B. Evolutionary classification
1. Biologists now group organisms into
categories that represent lines of evolutionary
descent or phylogeny not just physical
similarities. This is called evolutionary
classification.
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C. Classification Using Cladograms
1. Characteristics that appear in recent parts
of a lineage but not in its older members are
called derived characters.
2. Derived characters can be used to
construct a cladogram- a diagram that shows
evolutionary relationships among a group of
organisms.
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D. Similarities in DNA and RNA
1. The genes of many organisms show
important similarities at the molecular level.
2. Similarities in DNA can be used to help
determine classification and evolutionary
relationships.
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DNA-left RNA-Right
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III. Kingdoms and Domains
A. The tree of Life Evolves
1. The six-kingdom system of
classification includes the kingdoms,
Eubacteria, Archaebacteria, Protista,
Fungi, Plantae and Animalia.
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B. The three- Domain System
1. The domain is a more inclusive
category than any other.
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2. The three domains are:
a. Eukarya-which is composed of
protista, fungi, plantae and animals.
b. The domain bacteria, which
corresponds to the kingdom Eubacteria.
c. Domain Archaea, which corresponds to
archaebacteria.
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C. Domain Bacteria
1. Bacteria are unicellular and prokaryotic
(does not have a nucleus).
2. The cell walls contain a substance known
as peptidoglycan.
3. These bacteria are ecologically diverse,
ranging from free-living soil organisms to
deadly parasites.
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4. Some photosynthesize and some do
not.
5. Some need oxygen and some do
not.
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C. Domain Archaea
1. They are also unicellular and
prokaryotic.
2. Bacteria that live in the most extreme
environments possible.
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E. Domain Eukarya
1. Consists of all organisms that are
Eukaryotic (cells that have a nucleus)
2. Protista are eukaryotes that cannot be
classified as a plant, fungus or an animal.
3. Members of the kingdom Fungi are
heterotrophic. Most feed on dead or decaying22
organic matter
4. Members of kingdom plantae are
multicellular organisms that are
photosynthetic and Autotrophic.
5. Members of the kingdom Animalia
are multicellular and heterotrophic.
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Protists
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Fungi
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Plants
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Animals
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The End
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