Download Diversity of Organisms and Classification

Classification and the
Diversity of Life
Three-Domain System
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Alternative to Six-Kingdom System
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Because all organisms have ribosomes,
rRNA molecules can be used to study
the relationships between any two
organisms.
Early System of Taxonomy
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Aristotle (2000 yrs ago)
– Used 2 kingdoms
• Plant
–Herbs
–Shrubs
–Trees
• Animal
–Land-dwelling
–Air-dwelling
–Water-dwelling
Early System cont’d
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Polynomial system (Middle Ages)
– Biologists added a series of (up to 12) descriptive
terms to the name of the genus when they wanted
to refer to a particular kind of organism.
– Too cumbersome!
– For example:
• European honeybee was called
Apis pubescens, thorace subgriseo, abdomine
fusco, pedibus posticis glabris utrinque margine
ciliatis.
Carolus Linnaeus (1707-1778)
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the “Father of Modern
Taxonomy”
Based his system of
classification on morphology
Created the system of
Binomial Nomenclature
– For example:
• European honeybee
became:
Apis mellifera (genus,
species)
Linnaeus’ Levels of
Classification
Kingdom
Phylum / Division
Class
Order
Family
Genus
Species
Systematic Taxonomy
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Classifies organisms within the context
of evolution
Uses evidence of evolution to create a
phylogenetic tree:
– The fossil record
– Morphology
– Embryology
– Similarities in DNA
Six Kingdom System
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Archaebacteria
Eubacteria
Protista
Fungi
Animalia
Plantae
Archaebacteria & Eubacteria
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Unicellular
No nucleus
– Prokaryotic
Attain nutrients in
various ways:
– Saprophytic
– Parasitic
– Chemosynthetic
Protists
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Usually uni-cellular
Nucleus present (Eukaryotic)
Autotrophic (algae) or heterotrophic
Reproduce asexually and some also
reproduce sexually
Examples of Protists:
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Plasmodium (malaria)
Trypanosoma (African sleeping
sickness)
Green algae
Red algae
Slime mold
Paramecium
Amoeba
Giant Kelp
Fungi
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Eukaryotic
Non-photosynthetic
(no chlorophyll)
– Saprophytic or
parasitic
No root, stem or
leaf
Reproduce by
forming spores
Examples of Fungi:
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Yeast
Bread mold
Mushrooms
Lichens
Penicillum (produce the antibiotic)
Microsporum (ringworm)
Trichophtyon (Athlete’s foot)
Animals
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Phylum Chordata:
• Subphylum Urochordata
• Subphylum Cephalochordata
• Subphylum Vertebrata
10 Phyla of Invertebrates:
– Examples: Cnidaria, Mollusca,Nematoda.
Animals-- Key Characteristics
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Multi-cellular
Heterotrophic
No cell walls
1. Invertebrates
Invertebrates
Invertebrates
2. Vertebrates (Subphylum
Vertebrata)
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Divided into 7 Classes:
1) Bony Fish
2) Amphibians
3) Reptiles
4) Birds
5) Mammals
6) Lampreys & Hagfishes
7) Sharks, Rays, & Skates
a. Bony Fish
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Have jaws and a
bony skeleton
Cold-blooded
Have scales
Streamline body for
easy movement
through water
Fins for balance and
to control movement
Gills for breathing
External fertilization
b. Amphibians
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Cold-blooded
Skin is thin and
permeable to water.
External fertilization
Lay eggs in water
Larvae (tadpoles) use
gills for breathing;
adults use lungs
c. Reptiles
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Cold-blooded
Scales
Live on land
Breathe with lungs
Internal fertilization;
lay shelled eggs
d. Birds
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Warm-blooded
Feathers
Wings
Beaks
Lungs
Internal fertilization;
lay shelled eggs
e. Mammals
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Warm-blooded
Hairs on skin
Females produce milk
Internal fertilization;
embryos develop
inside mothers’ bodies
f. Lampreys & Hagfishes
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Elongated, eel-like bodies
Lack jaws
Have paired fins and a bony skeleton
g. Sharks, Rays, & Skates
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Have jaws and paired fins.
Skeleton is made of cartilage
E. Plants
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Eukaryotic
Most plants contains photosynthetic
pigments (e.g. chlorophyll) for
photosynthesis
– Autotrophic
Can be divided into three groups:
1. Non-vascular plants
2. Vascular, seedless plants
3. Vascular, seed plants
1. Non-vascular plants
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Lack vascular tissue and
do not have true roots,
stems, and leaves.
Reproduce by spores
3 Phyla:
– Moss (Bryophyta)
– Liverworts
(Hepatophyta)
– Hornworts
(Anthocerophyta)
2. Vascular, seedless plants
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Have true roots,
stems, leaves
and vascular
tissues (phloem
and xylem)
Reproduce by
spores
Live in damp
places
Vascular, seedless plants cont’d
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4 Phyla:
– Whisk Ferns
– Club mosses
– Horsetails
– Ferns
3. Vascular, seed plants
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Two groups:
– Gymnosperms
– Angiosperms
Gymnosperms
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Reproduction by
producing seeds
– Seeds develop
in cones, not
enclosed by
fruits
 naked seeds
Needle-shaped
leaves to reduce
water loss
Angiosperms (flowering plants)
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Have flowers for
reproduction
Seeds are
produced inside
the fruit (matured
ovary)
Three-Domain System cont’d
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Domain Archaea (= Kingdom
Archaebacteria)
Domain Bacteria (= Kingdom
Eubacteria)
Domain Eukarya (= Kingdom Protista,
Fungi, Plantae, and Animalia)