CLASSIFICATION

Why do we classify things?

* Classification provides scientists and students a way to sort and group organisms for easier study.
* There are millions of organisms on the earth! (approximately 1.5 million have been already named)

Organisms are classified by their:
* physical structure (how they look)
* evolutionary relationships
* embryonic similarities (embryos)
* genetic similarities (DNA)
* biochemical similarities

UNITY AND DIVERSITY

All living things carry out the life functions. There are many different types of organisms.


In one classification system, there are 2 main groups. In others, there are 3. In the one used by most of the world's scientists, which we will also use, there are 5 main groups. All living things are placed in one of the five KINGDOMS...which are the most general group. They are then broken down into smaller groups, then smaller groups, then smaller and so on until there is just one... SPECIES is the most specific group...

K P C O F G S

Can you make a sentence using the first letter of each classification subgroup?

* TAXONOMY--the branch of science that classifies and names living things.

* NOMENCLATURE--a system for naming things

In biology there is a two-word system that is used to name organisms. It is called
BINOMIAL NOMENCLATURE (a two named--naming system).

Carolus Linnaeus devised this in the 1800's using these two subgroups for the name:

GENUS & SPECIES
(more general) (more specific)

* Humans are known as Homo sapiens


The Five Kingdoms

MONERA
PROTISTA
FUNGI
PLANT
ANIMAL

M P F P A

Can you make a sentence using the first letter of each kingdom?

Organisms are groups among these five kingdoms by:
* the presence or absence of a nuclear membrane
* unicellular (one cell) or multicellular (many cells)
* the type of nutrition used by the organism (heterotrophic or autotrophic)

We will also go into the main phyla (next subgroup) for each kingdom.


I. Kingdom MONERA--
* have a primitive cell structure lacking a nuclear membrane--PROKARYOTE
* most of this kingdom are unicellular (some exist in multicellular clusters)
* two main phyla

A) Bacteria (heterotrophic)
B) Blue-green algae (autotrophic)

II. Kingdom PROTISTA--
* has a membrane around the nucleus of the cell--EUKARYOTIC
* predominantly unicellular
* two main phyla

A) Protozoa--animal like nutrition (heterotrophic)

ex. paramecia, ameba


B) Algae--plant like nutrition (autotrophic)

ex. spirogyra


III. Kingdom FUNGI--
* has a membrane around the nucleus of the cell--EUKARYOTIC
* absorbs food from its environment (heterotrophic), does NOT ingest it!
* organized into branched, multinucleated filaments

ex. bread molds (multicellular)
mushrooms (multicellular)
yeast (unicellular)

IV. Kingdom PLANTS--
* has a membrane around the nucleus of the cell--EUKARYOTIC
* multicellular organisms
* photosynthetic organisms (autotrophic)

(photo=light) (synthesis=to make)

PHOTOSYNTHESIS=TO MAKE FROM LIGHT

V. Kingdom ANIMAL--
* largest of 5 kingdoms
* has a membrane around the nucleus of the cell--EUKARYOTIC
* multicellular
* ingests their food (heterotrophic)
* four main phyla

A) Coelenterates (soul-en-ter-ates)

1) has only two layers of cells
2) has a hollow body cavity
ex. hydra, jellyfish

B) Annelids

1) has segmented body walls (rings)
ex. earthworm, sandworm

C) Arthropods

1) has an exoskeleton (exo=outside)
2) has jointed appendages
ex. grasshopper, lobster, spiders, insects

D) Chordates

1) have a dorsal (back) nerve cord
2) have an endoskeleton (endo=inside)
ex. sharks, frogs, humans, cats

**Chordates have many CLASSES (the next subgroup)**
Pisces (ex. fish)
Amphibians (ex. frogs)
Reptiles (ex. lizards)
Aves (ex. birds)
Mammalia (ex. humans, cats, dogs, whales)

SUMMARY OF THE KINGDOMS

Classification

Dichotomous Key
this clip shows some of the many species found on planet earth
basic text of the classification subgroups
great flash animations showing how and why we classify living things
Play as a mosquito or a parasite to reproduce and spread malaria. It has a little binomial nomenclature review in here as well...
LIGERS!
take a look at some of the history of binomial nomenclature
an overall review of the entire Classification packet
Tim and Moby discuss the 5 kingdoms
Tim and Moby discuss bacteria
exactly what is algae?
Who would have thought that there are this many crocs? take a look at an interesting comparison of the different croccodile species in this PBS interactive
we are one of the members of this branch of the animal kingdom