THE CLASSIFICATION SYSTEM

THE CLASSIFICATION

SYSTEM

WHY do scientists classify living things?

Answer: Classifying living things makes iteasier to find and share informationabout them.

HOW do scientists classify living things?

Answer: All living things can be classified intoone of five kingdoms. A kingdom is the largest group into which living things can be classified.

Every member of a kingdom has some characteristics that are the same as those of other members.

THE CLASSIFICATION SYSTEMThe Five Kingdoms

Fungi MoneransProtistsAnimals Plants

Description:

Most many-celled, absorb

food fromother living

things or deadthings such

as logs

Description:

Most one-celled, make

their ownfood or feedon living oronce living

things

Description:

One-celled,no cell nuclei,some maketheir own

food, somefeed on livingor once-living

things

Description:

Many-celled,make theirown food

Description:

Many-celled,feed on livingor once living

things

Examples:

Bacteria

Examples:

Monkeys,birds, frogs,fish, spiders

Examples:

Mushrooms,yeasts,molds

Examples:

Trees,flowers,grasses,

ferns,mosses

Examples:

Algae,amoebas,diatoms

Scientists divide the animal kingdom into

two large groups.ANIMAL KINGDOM

Vertebrates

Animalswith

a backbone

Invertebrates

Animalswithout

a backbone

Amphibians BirdsFishMammals Reptiles

Description:

Have moistskin and noscales, mostbegin life inwater, butlive on land

as adults

Description:

Live theirentire livesin water,

most havehard scales

covering theirbodies and gills to takeoxygen theyneed fromthe water

Description:

Have feathersto keep it warm andhelp some

to fly

Description:

Have dry,scaly skin

Description:

Have hairand produce

milk fortheir young

Examples:

Owls, robins,parrots,penguins

Examples:

Cats, dogs

Examples:

Frogs, toads,newts

Examples:

Lizards,snakes,turtles

Examples:

Sharks, eels,bass, tuna

VERTEBRATES

BirdsFish

Description:

Live theirentire livesin water,

most havehard scales

covering theirbodies and gills to takeoxygen theyneed fromthe water

Description:

Have feathersto keep it warm andhelp some

to fly

Examples:

Owls, robins,parrots,penguins

Examples:

Cats, dogs

Examples:

Frogs, toads,newts

Examples:

Lizards,snakes,turtles

Examples:

Sharks, eels,bass, tuna

MollusksArthropods

Description:

May or maynot have a

hard outer shell

Description:

Have legs withseveral joints,bodies

have two or moreparts, often

have an outercovering thatprotects them

Examples:

Snails, clams,squids

Examples:

Insects such asbeetles,bees,and spiderssuch as mites,horseshoe

crabs, and scorpions

INVERTEBRATES

Worms

Examples:

Earthworms,tapeworms,flatworms

Description:

Have no shells,legs, or eyes

Scientists study the living things in each kingdom to see how they are alike and how they are different.

They use characteristics to make smaller and smaller groups, and they give each smaller

group a name.

The most specific classification groups have only one type of living thing.

Forming Smaller Groups

Classification of a House Cat Kingdom: Animalia Phylum:   Chordata Class:   Mammalia Order:   Carnivora

Species:   domesticus

Family:  Felidae Genus:   Felis

Most living things have a common name such as house cat. But

common names may be different in different places.

For this reason, scientists name animals with the labels of the two smallest classification groups.

The name of the second smallest group, the genus, is joined with the name of

the smallest group, the species.

The scientific name for a house cat is Felisdomesticus.

Summary

Scientists organize living things to make studying and discussing them easier.

Scientists classify all living things into five kingdoms – animals, plants, fungi, protist, and monerans.

The five kingdoms are divided into smaller groups.

Vertebrates such as mammals, reptiles, amphibians, birds, and fish, have backbones.

Invertebrate animals, such as arthropods, mollusks, and worms, do not have backbones.