Transcript Classification of Organisms

Classification of
Organisms
HW:
Taxonomy
 The
assignment of a distinctive
name to each of the groups in a
classification system.
Animal Systematics
 What
is systematics?
–The study of the kinds and
diversity of organisms and the
evolutionary relationships
among them.
Three schools of
Systematics
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1. Evolutionary Systematics: Grouping
based on evolutionary relationships.
Homologous and analogous relationships
are both important.
2. Cladistics: Grouping also based on
evolutionary relationships. Only
homologous relationships are important.
3. Numerical Systematics: Grouping
based on math models and the
number/proportion of characteristics per
animal.
Classification System
(Modern)
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Seven levels of classification (taxa)
(Domain)
1. Kingdom
2. Phylum
3. Class
4. Order
5. Family
6. Genus
7. Species
Classification System
(Modern)
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Taxa begin with the largest, broadest
groups to the smaller, more specific
groups.
5 Kingdoms (recently
updated to 6)
1. Monera (a. Eubacteria;
b.Archaebacteria)
2. Protista
3. Fungi
4. Plantae
5. Animalia
Binomial Nomenclature –
Universal Naming system
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A scientific name of an organism contains
two parts. The first name is the genus name
and the second name is the species name.
Here are some simple rules in writing a
scientific name:
1. The first letter of the Genus name must
be capitalized.
2. The first letter of the species name is not
capitalized.
3. Both names must be underlined or
italicized.
Evolutionary Relationships
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Homologous features:
characteristics/structures that have a
similar origin but different function.
– Ex.
Evolutionary Relationships
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Analogous features:
characteristics/structures that have
different origins but the same function.
– Ex.
Common Classification
Terms
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Key: a structural map of taxa. Used to
place an animal into the correct group
by successfully eliminating choices.
Common Classification
Terms
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Symmetry: the layout of an animal’s body
1. Asymmetrical: no noticeable pattern or
shape, irregular
2. Radially symmetrical: circular or tubular
pattern. Cut halves look similar.
3. Bilaterally symmetrical: Left side a mirror
image of the right side down a longitudinal
plane.
Common Classification
Terms
Body Cavities CP 66
 1. Acoelomate – no body cavity
 2. Pseudocoelomate – (false body
cavity) an unlined body cavity
3. True coelomate - a body cavity lined
with peritoneum.
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Common Classification
Terms
Digestive systems
 1. Two-way digestive system: only has
one opening (mouth) for food to enter
and wastes to exit.
 2. One-way digestive system: have
two openings (mouth, anus) for food to
enter and wastes to exit.
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Common Classification
Terms
Circulatory systems
 1. Open system: has blood vessels
that are not interconnected. Blood
empties into cavities or sinuses.
 2. Closed system: has blood vessels
that are interconnected in which blood
continuously flows.
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Common Classification
Terms
Skeleton
 1. Hydrostatic pressure – body fluids
support body
 2. Exoskeleton – skeleton covering
body tissue.
 3. Endoskeleton – body tissue covers
the skeleton.
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Common Classification
Terms
Movement
 1. Sessile: attached to one place;
rarely move
 2. Free floating: able to move but lack
control of direction
 3. Mobile: able to control movements.
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