Download Characteristics of Living Things

Characteristics of Living Things
Living things …
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reproduce
grow
develop
respond
adapt
need & use energy (food)
Classification / Taxonomy
Classification: Grouping of organisms based on
a set of criteria or characteristics.
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It is easier to retain (keep) & communicate
information when organisms are organized into
groups.
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Scientific names are used to prevent confusion
because common names vary in their use.
• Cougar / puma / mountain lion / panther
= names for the same animal
• Scientific name = Puma concolor
Historical Classification
Aristotle: Greek, lived ~2,350 years ago
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1st majorly accepted classification system.
Organisms were classified as animals or plants.
• Animal: had red blood & were grouped by habitat (air,
land, water) & morphology (appearance)
• Plant: no red blood; grouped according to size (trees,
shrubs, herbs) & structure.
Horseshoe crab blood
Carl Linnæus: Swedish, 1700’s
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1st formal taxonomic system
Invented binomial nomenclature (scientific names).
Classification based on physical characteristics.
• The more characteristics organisms share, the more
closely related they are.
Binomial Nomenclature: A scientific name
consisting of 2 parts (genus & species)
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Uses Latin (a “dead” language).
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The scientific name for humans: Homo
sapiens
Rules for Scientific Names
The 1st letter of the 1st word (genus) is capitalized.
The 2nd word (species) is not capitalized.
 If printed in a book, magazine, or online the
scientific name is italicized.
 If handwritten, the scientific name is u n de rlin e d .
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In a scientific paper the first time the name is
written, it is written in full (genus + species). After
the first mention it may be abbreviated:
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Homo sapiens = H. sapiens
 Panthera
 Felis
leo or Panthera leo
catus
 Puma
concolor
 Genus
species (scientific name)
Taxonomy
Taxa: A series of categories that organisms are
classified into.
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The more taxa that organisms have in common, the
more closely related they are to each other, & they
will have more features in common.
Each category is contained within another from
broadest to specific.
Taxonomic Levels
Domain: Largest, least complex level
Kingdom: All 6 kingdoms are in 1 of the 3 domains
Phylum: All phyla are in 1 of the 6 kingdoms
Class: All classes are in 1 of the many phyla
Order: All orders are in 1 of the many classes
Family: All families are in 1 of the many orders
Genus: All genera are in 1 of the many families
Species: Smallest (1 organism) most complex level. All species
belong to 1 of the many genera.
Taxonomic Levels
Did
King
Domain
Kingdom
Philip
Phylum
Come
Over
For
Good
Spaghetti
Class
Order
Family
Genus
Species
All organisms, simple
}
Scientific
name
1 organism, complex
kingdom
kingdom
kingdom
kingdom
phylum
phylum
class
class
order
family
genus
species
kingdom
genus
species
order
family
genus
kingdom
Domain
Eukarya
Eukarya
Eukarya
Eukarya
Kingdom
Phylum
Class
Order
Animalia
Chordata
Mammalia
Primates
Animalia
Chordata
Reptilia
Chelonia
Animalia
Arthropoda
Insecta
Diptera
Plantae
Anthophyta
Dicotyledonae
Fagales
Family
Genus
Species
Hominidae Emydidae
Homo
Terrapene
sapiens
carolina
Culilcidae
Culiseta
annulata
Fagaceae
Quercus
alba
cat
lion
leopard
wolf
Domain
Eukarya
Eukarya
Eukarya
Eukarya
Kingdom
Phylum
Class
Animalia
Chordata
Mammalia
Animalia
Chordata
Mammalia
Animalia
Chordata
Mammalia
Animalia
Chordata
Mammalia
Order
Family
Carnivora
Felidae
Carnivora
Felidae
Carnivora
Felidae
Carnivora
Canidae
Genus
Species
Felis
catus
Panthera
leo
Panthera
pardus
Canis
lupus
Student Worksheet: History of Classification
Modern Classification
Typological Species Concept: Grouping
organisms based on physical similarities.
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Based on the idea that species are unchanging,
distinct, natural types
Used by Aristotle and Linnæus
At one time these butterflies may have been classified as different species.
Biological Species Concept: Defines a species
as a group of organisms able to interbreed &
produce fertile (able to reproduce) offspring in
a natural setting.
These butterflies can interbreed & produce fertile offspring & are
classified as the same species.
Phylogenic Species Concept: Defines a
species as a particular organism that is unique
& shows a pattern of ancestry & descent.
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When a phylogenetic species branches it becomes
2 different species.
Phylogeny: evolutionary history of a species
Characters: Inherited features that vary among a
species used to construct patterns of descent.
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Can be morphological or biological
owl
grackle
hawk
Morphological characters: Physical similarities
that may indicate that 2 species are closely
related & had a common ancestor.
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Analogous: Physical structures with similar function but
different underlying structures.
Homologous: Physical structures with similar
underlying structures but different functions.
Biochemical Characters: Genetic components
used to determine relationships among
different species.
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DNA & RNA (made of nucleotides) used to create
an organism by combining amino acids into
proteins.