Download Notes Classification of Living Things

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.
2.
3.
4.
5.
6.
7.
Kingdom – largest category
Phylum
Class
Order
Family
Genus – a group of similar species
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: 4-20-09
1. 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.17
 Begin 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 similarities
 Show 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.
2.
3.
4.
5.
6.


Archaebacteria
Eubacteria
Protists
Fungus
Plant
Animal
Vertebrates
Invertebrates
Organism are placed into kingdoms…
Organism are placed into kingdoms…
 Divided by the following
characteristics:
Presence
of nucleus
Single or multi celled
Ability to make own food
Ability 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.
2.
Tracheophytes
Bryophyte
Bryophytes
 No true roots,
 No true leaves
 No true stems
 No vascular tissue
 ex. mosses
Tracheophytes
 true roots,
 True leaves,
 True stems
 have vascular tissue
6. Animal
Multi-cellular
 Move
 Obtain 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
1b. Bean elliptical or oblong
2a. Bean white
2b. Bean has dark pigments
3a. Bean evenly pigmented
3b. Bean pigmentation mottled
4a. Bean black
4b. Bean reddish-brown
Garbanzo bean
Go to 2
White northern
Go to 3
Go to 4
Pinto bean
Black bean
Kidney bean