Classification of Living Things

What is Classification?

Classify

• to classify means to group (organize) similar ideas, items, objects or information based on similarities.

• there are so many organisms it is necessary to classify organisms in order to study them and to organize the information properly

Taxonomy

• the science of grouping living things

• there are 1.3 million NAMED species

-over 1 million of these are in the Phylum Arthropoda (insects)

-350,000 are beetles

-there are 120,000 butterflies and moths

-there are 93,000 named species of mollusks

Phylum Chordata

• There are only 52,000 named species of Chordates. (animals with a backbone)

• Humans belong in the phylum Chordata.

Unnamed Species

• Scientist estimate there are 10-200 million species of living things that are unnamed.

Carolus Linnaeus

• known as the Father of Taxonomy

• He was a Swedish Botanist who developed our system for naming organisms.

• Linnaeus’s system gives a 2 word name to every organism - it is called binomial nomenclature.

Binomial Nomenclature

• two name system for identifying all living things.

• An organisms scientific name is based on it’s genus and species.

3 Domain System

• Relatively new concept - 1990. Founded by Dr. Woese at University of Illinois. GO ILLINI

• The 3 Domains are

1. Archaea

2. Bacteria

3. Eukarya

Old System

• 1969 began with 5 kingdom system

• 1977 began with 6 - 7 kingdom system

• Kingdoms -

1. Plant or Plantae 2. Protists

3. Animal or Animalia 4. Monerans

5. Fungi 6. Archaebacteria 7. Eubacteria

Current Levels of Classification

• Domain (from largest group to smallest)

• Kingdom

• Phylum (some books call this Division)

• Class

• Order

• Family

• Genus

• Species (the most specific)

•Did King Phillip Come Over For Greasy Spaghetti?

Prefixes

There are times when a group is extremely large and prefixes will be added to various classification levels.

Such as Superclass or Subclass

Scientific NamingOrganisms are classified based on:

1. similarities in body structure and systems, sizes, shape and colors

2. methods they obtain food

3. behavior

4. chemical make-up

Scientific Name

An organisms scientific name is it’s

GENUS and SPECIES

RulesRules for writing a scientific name

1. GENUS is always written first and always capitalized.

2. SPECIES is always written second and is written in lowercase. (NOT CAPITALIZED)

3. Both names are underlined or written in italics.

Homo sapiens or Homo sapiens

• This is the scientific name for a human.

• KNOW THIS AND KNOW HOW TO WRITE IT.

The Classification of Humans

• Domain - Eukarya

• Kingdom - Animalia

• Phylum - Chordata

• Class - Mammalia

• Order - Primata

• Family - Hominadae

• Genus - Homo

• Species - sapiens

The functions of a scientific name

1. Scientific names help scientist avoid errors in communication. There is only one scientific name for every organism.

2. Organisms with similar evolutionary histories are group together.

3. The scientific name gives descriptive information about the species.

4. The scientific name allow information about the organism to be organized and found efficiently.

Domain EukaryaThis domain includes 4 of the kingdoms.

1. Protists or Protista

2. Fungi

3. Plant or Plantae

4. Animal or Animalia

Kingdom Protists• These organisms in this kingdom are all eukaryotes

(organisms with cells with membrane bound nucleus and organelles)

• Include one celled or many celled organisms

• some make their own food (producers) while some obtain their food from other organisms (consumers)

• some move

• EX. Euglena, Diatoms, Radiolarian (an algae), Amoeba

Kingdom Fungi

• Also made up of organisms composed of eukaryotic cells

• one celled organisms, as well as, many celled organisms in this kingdom

• all members of this kingdom are consumers (obtain their food from other organisms)

• EX - Mushrooms

Kingdom Plantae

• All eukaryotic cells

• many celled organisms

• all producers - make their own food (photosynthesis)

• most contain chlorophyll

• EX - trees, flowers, etc.

Kingdom Animalia• Eukaryotic cells

• many celled (multicellular organisms)

• most move

• members are consumers. The may be herbivores (plant eaters), carnivores (meat eaters), or omnivores (both herbivores and carnivores).

• EX - Humans, horses, butterflies, ticks

Domain Bacteria• Include 2 Kingdoms the Monerans and Archaebacteria

• Members of this group are all prokaryotes (organisms without an organized nucleus)

• unicellular (single celled) organisms

• microscopic organisms (can’t see without a microscope)

• some organisms in this domain are harmful and cause disease

• others are beneficial (aid in making Swiss cheese)

• EX - Escherichia coli (E. coli) and Salmonella typhimurium

Domain Archaea• Contain kingdom Eukarya

• These organisms are prokaryotes

• they are a type of bacteria with different DNA structure than those found in Domain Bacteria

• The live in the Earth’s most extreme environments (hot springs and thermal vents in Yellowstone)

• also live in cow and termite intestines

Phylogeny

• an organisms evolutionary history

• tells scientist who the ancestors of an organism were and helps to classify them

• classification of many organisms is based on phylogeny

Field Guides

• manual/book used to identify organisms

• the keys to using field guides are divided into steps with two descriptions at each step. These keys are known as dichotomous keys

• after going through these steps with the keys you will come up with the scientific name

Common Names

• When speaking informally - we all use the common name of an organism and not its scientific name.

• Depending on what part of the world you are in an organism may have many different common names. EX. - mountain lion, puma, polecat, cougar - are some of the same animals 13 common names

• this creates errors in understanding

One scientific name

• The is only one scientific name for every organism.

• This avoids any confusion, everyone is clear on the organism being discussed

Factors that influence how organisms are

classified• Vertebrate or Invertebrate

vertebrate - animal with a backbone

invertebrate - animal without a backbone

Body Plans

• how an organisms body is arranged

• symmetry - balanced proportions - we are going to discuss 3 types of symmetry

• radial, bilateral and assymetrical

Radial Symmetry

• organism with a top and bottom usually display this type of symmetry

• EX. - hydra, starfish, daisy, octopus

Bilateral Symmetry

• organisms with a definite left and right side (mirror image)

• Bilateral means 2 sided

Asymmetry

• organisms with no distinct sides, no definite shape

• prefix “a” means without - therefore asymmetry means “without symmetry”

• EX. - sponges

Animal Movement

• sessile - when an organism is permanently attached to a surface

• free-living - organisms that are mobile and not parasitic

• parasite - an organism that lives in or on another organism (a host) and at the same causes harm to that organism

Important Terms:

• Dorsal - Top side of an organism.

• Ventral - Underneath (belly) side of an organism.

• Anterior - Front end of an organism. (end towards mouth)

• Posterior - Back end or rear end of an organism. (end towards anus)