classification is…the process of grouping · classification is…the process of grouping things...

Classification

There are around 2 million species that

have been described and scientists believe

there are anywhere from 4 million to over

100 million different kinds of life forms on

this planet. How do we figure this out?

Mathematical models!

Classification is…the process of grouping

things together based upon their

similarities.

Scientists do this in order to make it easier

to study living things.Mr. Blacher's 7th Grade Biology

Taxonomy is…the study of how living things

are classified. Taxonomists are the scientists

that do this.

How Did this all Start?

Dude #1

Aristotle was a Greek philosopher and

scientist who lived in the 300B.C.’s; he took a

shot at classifying critters. He observed animals

and grouped them into…swimming, walking, and

flying things. Nice try…but we don’t use these

groups…they’re too general.

Mr. Blacher's 7th Grade Biology

More About Aristotle…for inquiring

minds

Aristotle also grouped animals into: those

with blood and those without blood. That’s

sorta close to our vertebrate (backbone)

and invertebrate (no backbone) thing.

Even though we have made some changes, We still DO use his basic approach.


Dude #2

Carolus Linnaeus was a Swedish scientist

(mid-1700’s) who followed up on Aristotle’s

work.

He developed the system of using two names,

so that scientists could communicate regardless

of the language they spoke. We call this:

BINOMIAL NOMENCLATURE.

The first word is the genus and the second is

usually an adjective that describes the

organism (or where its from or who

discovered it). More on this in a few slides.


Eight Levels of Classification

(and one way to remember them)

Domain…Dumb

Kingdom…Kings *Phylum…Play

Class…Chess Order…On

Family…Fancy

Genus…Glass

Species…Stools

Domains are the broadest category and species the most…ummm…specific.

*In plants…we call these DIVISIONS…sorry!Mr. Blacher's 7th Grade Biology

Domains

Domains were added to the taxonomic

system to take evolutionary differences

and differences in DNA.

This level is the broadest in scope.

There are three DOMAINS: Archaea,

Bacteria, and Eukarya.


The Six KingdomsWe’ll look at each in more detail later.

1. Archaebacteria

2. Bacteria (formerly Eubacteria)

3. Protists

4. Fungi

5. Plants

6. Animals


In this system of naming living things using two names, we use the genus and speciesnames.

Genus: a grouping that contains several similar organisms.

Species: an even smaller group within which organisms can mate and produce fertile offspring.

Example: Crocodylus porosus (salt water crocodile), Crocodylus niloticus (Nile crocodile)…same genus; different species.

Notice that the genus name is upper case and the species name…lower case.


Dichotomous Keys

AKA: Taxonomic Key

A bunch of paired statements that

describe the physical characteristics of

living things.

You make observations; follow the key;

and BINGO! Instant identification

Turn to page 226 and figure out what

organisms are pictured by using the

dichotomous (taxonomic) key.


Checkpoint Question #1!?!?!?

What were the three main groups of animals

in Aristotle’s system of classification?

A) Large animals, small animals, and

medium-sized animals

B) Mammals, fish, and reptiles

C) Those that fly, those that swim, and

those that can walk, crawl, or run


Checkpoint Question #2!?!?!?!?

In a scientific name, the genus name is

similar to

A) Your species name.

B) Your family name.

C) Your nickname.



What are the seven levels of classification

from the broadest to the most specific?

A) Domain, kingdom, phylum, class, order,

family, genus, species

B) Kingdom, phylum, order, class, family,

genus, species

C) Kingdom, phylum, family, order, genus,

species



Who developed one of the earliest

classification system for organisms?

A) Aristotle

B) Linnaeus

C) Darwin



In the scientific name of a house cat, Felis

domesticus, “felis” is the name of the

animal’s

A) Species

B) Family

C) Genus



A taxonomic key is

A) a book with illustrations that highlights differences between similar-looking organisms.

B) a process for determining the evolutionary history of an organism.

C) a series of paired statements that describe the physical characteristics of different organisms.


Answers!!!

1-C

2-B

3-A

4-A

5-C

6-C


classification is…the process of grouping · classification is…the process of grouping things...

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