6-4 Notes – Classifying Organisms
Historic Classification Systems
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_____________________ , a Greek philosopher, was one of the first people to put organisms into categories.
He categorized things as ___________ , __________ , or ________________ , and then according to where they
____________—air, land, or sea.
In the mid-1700s, Swedish botanist, _______________ developed a classification system that grouped organisms by
similar ________________ _______________________.
Linnaeus’s system went from ____________ (most general) to ____________ (most specific).
Members of a ____________ group have the greatest number of ___________ in common and can ____________ and
produce ______________ offspring.
Only species are subject to _____________ ______________________ and ___________.
Linnaeus also developed a system for ______________ species that is still used.
Each species has a _____-word scientific name called its ____________ _____________.
The first word identifies its ______________.
Human’s species name is _________ _______________.
Basic features such as cell type, presence of a cell wall, or single-celled versus multicellular define each of the 6
kingdoms: ______________________ , ________________________________ , _______________ , _____________ ,
_______________ , & __________________________ .
Modern Methods of Classification
• The modern study of classification, called ___________________ , uses ______ and _______________ biology to
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identify related organisms.
The more shared ______ sequences two species have, the more recent _______________ they probably share.
Scientists use _______________ , samples of _______ base pairs, to compare DNA sequences among organisms.
DNA __________________ measures the percentages of ______ that are the same between two organisms.
Molecular biology led to a new highest level of classification called “_______________ ,” which is based on differences
in a particular ___________ sequence. There are 3 domains: ______________ , ______________ , ______________
As more sophisticated techniques are developed, the ________________ system will continue to become more refined.
The current system of classification (from highest to lowest -or- largest to smallest -or- most general to most specific):
1. _____________________________
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_____________________________
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p. 53
Cladograms
• Scientists create diagrams called __________________ to
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group organisms based on certain characteristics.
A cladogram shows common ________________ , and
helps scientists to better understand _________________.
MYA
Review
____ 1. What was Linnaeus’ classification system based on?
A. whether things were plant, animal, or mineral
B. where organisms lived—air, water, or land
C. similar DNA sequences
D. similar physical structures
____ 2. What approach measures the percentage of DNA that is similar between two organisms?
A. DNA hybridization
C. haplotypes
B. DNA sequencing
D. systematics
____ 3. What is currently the highest level of classification?
A. animalia
B. domian
C. kingdom
D. order
____ 4. Which does not provide independent evidence for the theory of evolution through natural selection?
A. fossil record
C. systematics
B. comparative anatomy
D. molecular biology
____ 5. Which of the following is not a kingdom?
A. protista
B. fungi
C. eukarya
D. animalia
6-4 Notes – Classifying Organisms
Historic Classification Systems
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•
•
•
•
•
•
•
•
•
•
Aristotle, a Greek philosopher, was one of the first people to put organisms into categories.
He categorized things as animals, plants, or minerals, and then according to where they lived—air, land, or sea.
In the mid-1700s, Swedish botanist, Linnaeus developed a classification system that grouped organisms by similar
physical structures
Linnaeus’s system went from kingdom (most general) to species (most specific).
Members of a species group have the greatest number of traits in common and can breed and produce fertile offspring.
Only species are subject to natural selection and evolve.
Linnaeus also developed a system for naming species that is still used.
Each species has a two-word scientific name called its species name.
The first word identifies its genus.
Human’s species name is Homo sapien.
Basic features such as cell type, presence of a cell wall, or single-celled versus multicellular define each of the 6
kingdoms: Eubacteria, Archaebacteria, Protists, Fungi, Plantae, & Animalia
Modern Methods of Classification
• The modern study of classification, called systematics, uses DNA and molecular biology to identify related organisms.
• The more shared DNA sequences two species have, the more recent ancestor they probably share.
• Scientists use haplotypes, samples of 1000 base pairs, to compare DNA sequences among organisms.
• DNA hybridization measures the percentages of DNA that are the same between two organisms.
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Molecular biology led to a new highest level of classification called “Domain,” which is based on differences in a
particular genetic sequence. There are 3 domains: Bacteria, Archaea, Eukarya
As more sophisticated techniques are developed, the classification system will continue to become more refined.
The current system of classification (from highest to lowest -or- largest to smallest -or- most general to most specific):
1. Domain
2. Kingdom
3. Phylum
4. Class
5. Order
6. Family
7. Genus
8. Species
Cladograms
• Scientists create diagrams called cladograms to group
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organisms based on certain characteristics.
A cladogram shows common ancestry, and helps
scientists to better understand evolution.
MYA
Review (Answers: 1-D, 2-A, 3-B, 4-C, 5-C)
____ 1. What was Linnaeus’ classification system based on?
A. whether things were plant, animal, or mineral
B. where organisms lived—air, water, or land
C. similar DNA sequences
D. similar physical structures
____ 2. What approach measures the percentage of DNA that is similar between two organisms?
A. DNA hybridization
C. haplotypes
B. DNA sequencing
D. systematics
____ 3. What is currently the highest level of classification?
A. animalia
B. domain
C. kingdom
D. order
____ 4. Which does not provide independent evidence for the theory of evolution through natural selection?
A. fossil record
C. systematics
B. comparative anatomy
D. molecular biology
____ 5. Which of the following is not a kingdom?
A. protista
B. fungi
C. eukarya
D. animalia