Classification

Focus ??

Using information from class, do you believe the classification system will

remain the same? WHY or WHY NOT??

Classification: A way to organize objects or group

objects in a logical manner according to their characteristics and

evolutionary history. Grouping similar objects together Ex.

Grocery store – fruit, meat, cereal are grouped

Shoe dept. – sneakers: running, cross training, basketball etc…

Reasons to classify:

Universal Easier to find Provide information about

the organism Avoid mistakes

Taxonomy

study of classification

Taxonomists:

Scientists who classify organisms:

Taxonomists:

Aristotle – 3 main groups: air, land, water, he also grouped plants

into three categories, based on differences in their stems.

Taxonomists:

Linnaeus: developed 7 levels of classification grouped organisms into

hierarchical categories used an organism’s morphology: its

form and structure, to categorize

Linnaeus Cont.:

Linnaeus’s categorization scheme used a hierarchy.

Seven levels of organization, each more specific than the last, allowed organisms to be grouped with similar organisms.

Linnaeus’ Classification Sys.

Modern day classification system:

Uses 7 taxonomic categories ( developed by Linnaeus): Each level is called a Taxon The levels are:

1. Kingdom – largest category

2. Phylum

3. Class

4. Order

5. Family

6. Genus – a group of similar species

7. Species – most specific category,

Species:

Might tell:

1. What it looks like

2. How it tastes or smells

3. Where it’s found

4. Who discovered it

STOP!!! CK POINT!!

Topic: Intro to Classification Date: 4-20-091. What is the goal of classifying

organisms?2. Who the 2 taxonomists who are given

credit for shaping taxonomy and classifying organisms?

3. What did each taxonomist contribute to the classification system?

In your packet:

Turn to page 121-122 in the packet Get a whale text book, ch.17Begin answering questions

DO NOT FORGET HMWK

DUE WED!!!!

Binomial Nomenclature:

2 word naming system (scientific name) Latin, same in every language…universal 1st word – genus: identifies a group, capitalized 2nd word – species: share characteristics and reproduce among one another producing fertile offspring Both are underlined or italicized Ex. 1. Acer rubrum Maple Red = red maple tree

2. Acer saccharum Maple sugar = sugar maple trees

Phylogenic tree:

To classify organisms, modern taxonomists consider the phylogeny (fie-LAHJ-uh-nee), or evolutionary history, of the organism

Shows the evolutionary relationships among organisms

Based on several lines of evidence Fossil record may provide the

basis/framework of a phylogenic tree

Modern Classification System

Evolutionary Classification:Grouping organisms based on

evolutionary descent or common ancestors

Not limited to physical similaritiesShow relationships based on

genetic similarities

Taxonomists use:

1. Homologous

structures –

similar structures,

similar

development,

function is

different Ex. Bird wing and

the human arm

Taxonomists use:

2. Analogous structures – structures appear similar, function similar, different development Ex. Bird wing and the wing of a butterfly

Cladogram:

diagram that shows evolutionary relationships among organisms based on shared derived characteristics

a type of tree showing evolutionary relationships

begin at the bottom and move up the further away from a common

ancestor, the more different their genes

derived character –ADD TO NOTES

Cladistics uses certain features called shared derived characters,

a feature that apparently evolved only within the group under consideration.

Modern Classification System Cont.

Separated into 3 Domains:

1. Bacteria- Eubacteria

2. Archaea - Archaebacteria

3. Eukarya (eukaryotes) - includes protests, fungi, plants, and animals

3 domains:

are separates into 6 kingdoms:

1. Archaebacteria2. Eubacteria3. Protists4. Fungus5. Plant6. Animal Vertebrates Invertebrates

Organism are placed into kingdoms…

Organism are placed into kingdoms…Divided by the following

characteristics:Presence of nucleusSingle or multi celledAbility to make own foodAbility to move

Kingdom 1. Arachaebacteria: :

Unicellular Some movement Some make own food = Some obtain food from environment = No nucleus present Live in hostile

environment like Heat, pH

Kingdom: 2. Eubacteria: Unicellular Some movement Some make own food = Some obtain from environment = No nucleus present

Bacilli (rod), cocci (spherical), spirilla (spiral)

3. Protista:

Unicellular or multi-cellular

some move some make own

food some obtain food

from environment contain a nucleus

4. Fungi Some are Unicellular Most are multi-cellular Do not move All fungus obtain food from

environment =

5. Plants

Multi-cellular Do not move Make own food = 2 types:

1. Tracheophytes

2. Bryophyte

Bryophytes

No true roots, No true leavesNo true stemsNo vascular tissue ex. mosses

Tracheophytes

true roots, True leaves, True stems have vascular tissue

6. Animal

Multi-cellularMoveObtain food from environment-

Organisms in each kingdom are

then classified into the remaining 6 Levels:

Kingdom, phylum, class, order, family, genus, specie

Dichotomous Keys:

Also called a field guide, & taxonomic key

Use descriptions about external features to help identify the name of the organism

Arranged with 2 statements describing the organism

Dichotomous Keys Cont:

Using the key gives you the binomial nomenclature (2 word name): genus and specie of the organism

Identifies specific organisms

1a. Bean round Garbanzo bean1b. Bean elliptical or oblong Go to 2

 2a. Bean white White northern2b. Bean has dark pigments Go to 3

     3a. Bean evenly pigmented Go to 43b. Bean pigmentation mottled Pinto bean     4a. Bean black Black bean4b. Bean reddish-brown Kidney bean