Classification of Living Things

Activity

• 1 Whole

• Make a Family tree using a graphic organizer. Tracing your origin from your grandparents to grand children.

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ClassificationClassification

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The Challenge

• Biologists have identified and named approximately 1.5 million species so far.

• They estimate that between 2 and 100 million species have yet to be identified.

• 1. Why Classify?– To study the diversity of life– To organize and name organisms

• 2. Why give scientific names?– Common names are misleading

Finding Order in Diversity

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jellyfish silverfish star fish

None of these animals are fish!

• Different levels of classification are analogous to a postal address. 1st sorted by country, then provinces, followed by municipality, and by district or barangay. The mailman then finds the street and house number until the letter reaches the recipient.

Philippines

Isabela

Quezon

Samonte District

23 Rizal St.

Bucaneg

Phylum/Division

Class

Family

Genus

Kingdom

Order

Pedro Species

Chordata

Mammalia

Hominidae

Homo

Animalia

Primata

Phylum/Division

Class

Family

Genus

Kingdom

Order

Species Sapiens

Some organisms have several common names

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This cat is commonly known as:

•Florida panther

•Mountain lion

•Puma

•Cougar

Scientific name: Felis concolor

Scientific name means “coat of one color”

Why Scientists Assign Scientific Names to Organisms

Origin of Scientific Names

• By the 18th century, scientists realized that naming organisms with common names was confusing.

• Scientists during this time agreed to use a single name for each species.

• They used Latin and Greek languages for scientific names.

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Linnaeus: The Father of Modern Taxonomy

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Carolus Linnaeus

1732: Carolus Linnaeus developed system of classification – binomial nomenclaturea. Two name naming system

b. Gave organisms 2 names

Genus (noun) and species (adjective)

Rules for naming organisms

1. Written is Latin (unchanging)

2. Genus capitalized, species lowercase

3. Both names are italicized or underlined

EX: Homo sapiens: wise / thinking man

Kingdom

Phylum

Class

Order

Family

Genus

SpeciesGo to Section:

Linnaeus’s System of Hierarchy

Least specific

Most specific

1. Which of the following contains all of the others?

a. Family c. Class

b. Species d. Order

2. Based on their names, you know that the baboons Papio annubis and Papio cynocephalus do not belong to the same:

a. Family c. Order

b. Genus d. Species

Binomial Nomenclature Example• For example, the polar bear is named

Ursus maritimus.

• The genus, Ursus, describes a group of closely related bear species.

• In this example, the species, maritimus, describes where the polar bear lives—on pack ice floating on the sea.

Modern Classification

• Linnaeus grouped species into larger taxa, such as genus and family, based on visible similarities.

• Darwin’s ideas about descent with modification evolved into the study of phylogeny, or evolutionary relationships among organisms.

Modern Classification

• Modern biologists group organisms into categories representing lines of evolutionary descent.

• Species within a genus are more closely related to each other than to species in another genus.

Genus: Felis Genus: Canis

Felis domistica Canis familiaris

Similarities in DNA and RNA

• Scientists use similarities and differences in DNA to determine classification and evolutionary relationships.

• They can sequence or “read” the information coded in DNA to compare organisms.

Kingdoms and Domains

• In the 18th century, Linnaeus originally proposed two kingdoms: Animalia and Plantae.

• By the 1950s, scientists expanded the kingdom system to include five kingdoms.

The Five Kingdom SystemMonera

bacteria

Protista

Amoeba, slime mold

Fungi mushrooms, yeasts, molds

Plantae flowering plants, mosses, ferns, cone-bearing plants

Animalia mammals, birds, insects, fishes, worms, sponges

• Organisms belonging to Kingdom Monera are called PROKARYOTES because they lack a true nucleus, cytoskeleton and internal membranes.

• All other organisms are called EUKARYOTES because their cell nuclei and organelles are enclosed by membranes and they contain a cytoskeleton

• Living organisms can be classified as:

1.Unicellular- made up of single cell

2.Multicellular – made up of more than one cell

• Most monerans and protists are unicellular organisms, while all fungi, plants and animals are multicellular

The Six Kingdom System

• In recent years, biologists have recognized that the Monera are composed of two distinct groups.

• As a result, the kingdom Monera has now been separated into two kingdoms: Eubacteria and Archaebacteria, resulting in a six-kingdom system of classification.

• Kingdom Eubacteria – includes the true bacteria and cyanobacteria (phosynthetic bacteria)

• Kingdom Archaea- includes bacteria-like organisms that live in extremely harsh environment such us hotsprings, volcanic vents, sewage treatment plants, ocean floor and swamp sediments.

The Three-Domain System

• Scientists can group modern organisms by comparing ribosomal RNA to determine how long they have been evolving independently.

• This type of molecular analysis has resulted in a new taxonomic category—the domain.

The Three Domains

• The three domains, which are larger than the kingdoms, are the following:

• Eukarya – protists, fungi, plants and animals

• Bacteria – which corresponds to the kingdom Eubacteria.

• Archaea – which corresponds to the kingdom Archaebacteria.

BacteriaArchaea Eukarya

Prokaryotic ancestor (2 Billion years ago)

Prokaryotic ancestor (3 Billion years ago)

Origin of Life

Non of the three groups are ancestral or primitive to the other, and each domain shares certain features with the others as well as having unique characteristics of its own. Biologist believe that the three domains share a common prokaryotic ancestor

Classification of Living Things

The three-domain system

Bacteria Archaea Eukarya

EubacteriaArchae-bacteria

Protista Plantae Animalia

The six-kingdom system

Fungi

Grizzly bear Black bear Giant panda

Red fox Abert squirrel

Coral snake

Sea star

KINGDOM Animalia

PHYLUM Chordata

CLASS Mammalia

ORDER Carnivora

FAMILY Ursidae

GENUS Ursus

SPECIES Ursus arctos

Hierarchical Ordering of Classification

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As we move from the kingdom level

to the species level, more and more members are

removed.

Each level is more specific.

AssignmentNotebook:

1.List down the characteristics of the following Kingdoms

a. Kingdom Eubacteria

b. Kingdom Archaea

c. Kingdom Protist

d.Kingdom Fungi

e. Kingdom Plantae

f. Kingdom Animalia

Bird’s Eyeview of the Living World

The Six Kingdom of Classifiction

Kingdom Archaebacteria

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Cell Type Prokaryote

Number of Cells Unicellular

Nutrition Autotroph or Heterotroph

Location Extreme Environments Volcanoes, Deep Sea Vents, Yellowstone Hot Springs

Examples Methanogens

Thermophiles

Kingdom Eubacteria

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E. coli

Streptococcus

Cell Type Prokaryote

Number of Cells Unicellular

Nutrition Autotroph or Heterotroph

Examples Streptococcus, Escherichia coli (E. coli)

Kingdom Protista

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Paramecium

Green algae

Amoeba

Cell Type Eukaryote

Number of Cells Most Unicellular, some multicellular

Nutrition Autotroph or Heterotroph

Examples Amoeba, Paramecium, Euglena,

The “Junk-Drawer” Kingdom

Kingdom Fungi

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Mildew on Leaf

Mushroom

Cell Type Eukaryote

Number of Cells Most multicelluar, some unicelluar

Nutrition Heterotroph

Example Mushroom, yeast, mildew, mold

Most Fungi are DECOMPOSERS

Kingdom Plantae

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Ferns : seedless vascular

Sunflowers: seeds in flowers

Douglas fir: seeds in cones

Mosses growing on trees

Cell Type Eukaryote

Number of Cells Multicellular

Nutrition Autotroph

Examples Mosses, ferns, conifers, flowering plants

Kingdom Animalia

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Sage grouse

Poison dart frog

Bumble bee

Sponge

Jellyfish

Hydra

Cell Type Eukaryote

Number of Cells Multicellular

Nutrition Heterotroph

Examples Sponges, worms, insects, fish, mammals

CELL WALL

1. PEPTIDOGLYCAN: contain peptidoglycan, a complex web-like molecule; found only in the Eubacteria

2. UNCOMMON LIPIDS: nonpeptidoglycan, contains uncommon lipids, found only in Archaebacteria

3. PECTIN: contain pectin a complex polysaccharide, found in most Protista

3. CELLULOSE: contain cellulose a complex polysaccharide; found in Plantae

3. CHITIN: contain chitin, a tough material like that making up crab shells; found only in the Fungi

MODE OF NUTRITION (how obtain energy/gets food)

A. AUTOTROPHIC: make own food, contain chlorophyll (photosynthetic), (some without chlorophyll are chemotrophic)

B. HETEROTROPHIC: get food from other organism, no chlorophyll, ingestion or absorption (free living, parasitic, saprophytic)