ClassificationChapter 18

Taxonomy

The field of biology that deals with classifying organisms.

Each level is called a Taxon.

How do Taxonomists classify?

1. Physical Structures

2. Embryological Development

3. Chemical Processes

4. DNA

There are 8 major levels for classification!

Organisms within each category are:

more closely related as you move from the domain toward the species level!

SpeciesRecall… a species is a

group of organisms that share most

characteristics and can interbreed to produce

fertile offspring.

Domains are:The largest groups in the modern classification system.

There are 3 domains shown above.

The next level down from domain is…

Kingdom

As shown above, each domain includes:

1 or more kingdoms of organisms

Domain Bacteria Archaea Eukarya

Protista Fungi Plantae AnimaliaArchaebacteriaEubacteriaKingdom

The domain Bacteria is made up of:

1 Kingdom: Eubacteria “true bacteria”

Domain Bacteria Archaea Eukarya

Protista Fungi Plantae AnimaliaArchaebacteriaEubacteriaKingdom

Recall that bacteria:are single celled prokaryotes. Their cell walls

contain a substance called

peptidoglycan

The domain Archaea also contains:

1 kingdom, archaebacteria.

Domain Bacteria Archaea Eukarya

Protista Fungi Plantae AnimaliaArchaebacteriaEubacteriaKingdom

The cell walls of archaea DO NOT contain Peptidoglycan.

Archaea live in extreme environments like thermal vents and salt lakes.

The domain Eukarya contains 4 kingdoms:

Protista (protists), Fungi, Plantae (plants), and Animalia (animals)

Domain Bacteria Archaea Eukarya

Protista Fungi Plantae AnimaliaArchaebacteriaEubacteriaKingdom

All members of the Eukarya Kingdom are eukaryotes!

–Johnny Appleseed

“Autotrophs - Organism that makes its own food

Heterotroph - Feeds on other organisms.”

Kingdom Characteristics Examples

ProtistaUnicellular or Multicellular, nucleus, plasma

membrane. May have a cell wall and chloroplasts, includes heterotrophs and

autotrophs.

Euglenas, algae, paramecia, amoebas

FungiUnicellular or multicellular, has a

nucleus, plasma membrane, and cell wall. Only heterotrophs.

Yeasts, mushrooms, molds, mildews

PlantaeMulticellular, nucleus, plasma

membrane, cell wall, chloroplasts. Only autotrophs.

Mosses, ferns, trees, grasses

AnimaliaMulticellular, nucleus, plasma

membrane, no cell wall or chloroplasts, only heterotrophs.

Sponges, worms, insects, fish, amphibians, reptiles,

birds, mammals

Kingdoms in the Domain Eukarya

Kingdoms are divided into Phyla or Phylum

Phyla are subdivided into classes, then orders, family, genera, and species.

Binomial NomenclatureGiving each organism a 2 part name

First part of name is genus:

This includes related species

Second part of name identifies the organism’s

species

Binomial Nomenclature was created by:

A swedish botanist in the 1700’s: Carolus Linnaeus

PhylogenyEvolutionary history of a group of organisms.

Scientists show the development of

groups of organisms from a common ancestor

in branching diagrams called

Phylogenetic Trees.

Evolutionary Relationships can also be shown through:

Cladograms

Dichotomous Keys

A tool that can be used to determine the identity of something by matching

observations to a series of paired statements or

questions.