Classifying Organisms

Ch. 1.2

Focus Questions

1. What methods are used to classify

organisms into groups?

2. What is binomial nomenclature?

3. What tools can we use to classify

organisms?

1. What methods are used to classify

organisms into groups?

Aristotle (384 B.C.- 322 B.C.): 2 groups: plants & animals

Carolus Linnaeus (1700s): 2 kingdoms, multiple levels, & created a naming system

Robert H. Whittaker (1969): 5-kingdom system

Systematics (1990s): current system: 3 domains, 6 kingdoms

• The classification system of living things

is still changing.

• Systematics uses all known evidence

about organisms, such as:

– Cell type, its habitat, the way an organism

obtains food & energy, structure & function of

its features, common ancestry, and DNA

structure

1. What methods are used to classify

organisms into groups?

(LIFE)

Bacteria

Bacteria

Archaea

Archaea

Eukarya

Protista Plantae Fungi Animalia

8 levels of classification:

D

K

P

C

O

F

G

S

1. What methods are used to classify

organisms into groups?8 levels of

classification:

Domain

Kingdom

Phylum

Class

Order

Family

Genus

Species

8 levels of classification:

Daring

King

Phillip

Came

Over

For

Great

Spaghetti

What level of classification comes after

phylum?

A. Kingdom

B. Class

C. Order

D. Genus

Kingdom

Class

Order

Genus

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45

Who was one of the first people to

classify organisms?

a. Linnaeus

b. Whittaker

c. Darwin

d. Aristotle

Linnaeus

Whitt

aker

Darwin

Aristo

tle

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45

• Linnaeus’s naming system that gives each organism a 2-word scientific name (species).

• A species is a group of organisms with similar traits & with the ability to produce fertile offspring.

• Example: common house catEx: Felis domesticus

1st part =

Genus name2nd part =

specific name

2. What is binomial nomenclature?

What does the first part of a scientific

name refer to?

a. Genus

b. Species

c. Specific name

d. Family

Genus

Species

Specific

name

Fam

ily

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45

• Dichotomous key:

– A series of paired statements

• Cladograms:

– Branched diagram that shows relationships

among organisms (common ancestry)

3. What tools can we use to classify

organisms?

3. What tools can we use to classify

organisms?

Enter question text...Which animal is more closely related to

the chimp?

a. Lizard

b. Salamander

c. Mouse

d. Pigeon

Lizard

Salam

ander

Mouse

Pigeon

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45

What is the key difference (characteristic)

between the salamander and the lizard?

a. Jaws

b. Lungs

c. Claws or nails

d. Feathers

e. Fur, mammary

glands

Jaw

s

Lungs

Claw

s or n

ails

Feath

ers

Fur,

mam

mary

glands

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45

Which is more closely related to the

Perch?

a. Salamander

b. Lizard

c. Pigeon

d. Mouse

e. Chimp

Salam

ander

Lizard

Pigeon

Mouse

Chimp

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45

Physical similarities are the only

characteristics used to classify organisms.

a. Agree

b. Disagree

Agree

Disagre

e

00

30

A dichotomous key can be used to

identify unknown organisms.

a. Agree

b. Disagree

Agree

Disagre

e

00

30