DOMAINS AND KINGDOMS (CH 18 SEC 3)

Updating Classification Systems

Linnaeus created a system with two kingdoms Plantae(plants) and Animalia(animals)

The invention of the microscope lead to many changes in the classification system

Sponges were moved from the plant kingdom to the animal kingdom.

In the 1800s, all unicellular were lumped into Kingdom Protista

In the 1950s, Kingdom Monera was added for prokaryotes

In the 1990s, Monera was split into Eubacteria and Archaebacteria

How do we classify organisms into Domains and Kingdoms?

Cell Type

Cell Wall Type

Complexity

Nutrition

Prokaryote or Eukaryote

What is the cell wall made of?

Unicellular or Multicellular

Autotroph

Heterotroph

– Makes its own food

– Eats other organisms

Domain Bacteria

Kingdom Eubacteria (or “true bacteria”)

Cell Type - Prokaryotes

Cell Wall Type – Peptidoglycan

Complexity – Unicellular

Nutrition – Some are autotrophs; some are heterotrophs

Found in almost every habitat

Most abundant organisms on earth

Bacteria Examples

Domain Archaea

Kingdom Archaebacteria

Cell Type – Prokaryotes

Cell Wall Type – Unique Lipids

Complexity – Unicellular

Nutrition – Some are autotrophs; some are heterotrophs

Found anywhere including the most extreme environments on earth

Archaea Examples

Extremophiles

Found in extreme environments like hot springs, thermal vents and our stomachs

Methanogens

Live in oxygen-free environments

Domain Eukarya

Kingdoms

Protista, Fungi, Plantae, Animalia

Cell Type – All eukaryotes

Have organelles like a nucleus and membrane-bound organelles

Organisms are divided into kingdoms based on number of cells, body organization, and types of nutrition.

Kingdom Plantae

Cell Wall Type – cellulose

Complexity – Multicellular

Nutrition – Autotrophs

Photosynthesis

More than 300,000 known species

Includes mosses, ferns,

conifers, and flowering plants

Kingdom Animalia

Cell Wall Type – None!!!

Complexity – Multicellular

Nutrition – Heterotrophs

More than 1,000,000 known species

Includes sponges, worms,

arthropods, fish, amphibians,

reptiles, birds, and mammals

Kingdom Fungi

Cell Wall Type – Chitin

Complexity – Mostly multicellular

yeast (unicellular)

Nutrition – Heterotrophs

Secrete digestive enzymes onto food source and them absorb the minerals

More than 70,000 known species

Examples – molds, mushrooms, yeast, lichens

Kingdom Protista “leftover” group

Plant-like, animal-like, and fungus-like

Cell Wall Type – Some do/Some don’t

Complexity – Mostly unicellular

Some colonial organisms (algae); a few multicellular organisms (kelp)

Nutrition – Some are autotrophs; some are heterotrophs

May eventually be split into new kingdoms to better reflect evolutionary history

Over 115,000 species

Protist Examples