classification focus ?? using information from class, do you believe the classification system will...
TRANSCRIPT
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