Taxonomy
Classification & taxonomy
Classification is the grouping of objects or
information based on similarities.
 Taxonomy is the branch of biology
concerned with the grouping and naming of
organisms.

How living things are
classified
Organisms are grouped into groups called
taxa, each one larger than the previous one.
 The smaller the taxon, the smaller the
number of organisms in that group. These
organisms share greater similarity to each
other than those in the larger taxa.

Example:

Come up with a classification system to classify
students in this class. Think big to small

Ex. We are all Americans all the way to students in room
L309








Least specific
Americans
Texans
Residents of Tarrant County
Residents of Colleyville
Attend CHHS
Biology students
Biology students in Mrs. Kays class
Biology students in Mrs. Kays 4th period class
Most specific
Classification System

Did King Phillip Come Over For Good
Spaghetti?








Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Domain
This is the largest taxon.
 All organisms are placed in 1 of 3 groups.
 A group of related kingdoms.


3 Domains: Bacteria, Archae and Eukarya

Example: Humans are members of the Domain
Eukarya along with all other eukaryotic
organisms
Kingdom
This is the second largest taxon.
 All organisms are placed in 1 of 6 groups
based on their cell structure.
 A group of related phyla.


6 Kingdoms: Archaebacteria, Eubacteria, Protista,
Fungi, Plantae, Animalia

Ex: Humans are members of the kingdom
Animalia along with all other multicellular,
heterotrophic eukaryotes
Phylum (pl. phyla)
A smaller subcategory of a kingdom.
 A group of related classes.


Ex: Humans are members of the phylum cordata
along with all other organisms that have a
backbone
Class
A smaller subcategory of a phylum.
 A group of related orders.


Ex: Humans are members of the class mammalia,
along with all other organisms who have
mammary glands and hair
Order
A smaller subcategory of a class.
 A group of related families.


Ex: Humans are members of the order primates,
along with all other primates
Family
A smaller subcategory of an order.
 A group of related genera.


Ex: Humans are members of the family
hominidae along with all other great apes
Genus (pl. genera)
A smaller subcategory of a family.
 A group of related species.


Ex: Humans are members of the genus Homo
along with all other organisms that have specific
and specialized development of
memory/learning/teaching/learning application
Species
A smaller subcategory of a genus.
 A population of interbreeding organisms
capable of producing fertile offspring.


Ex: Humans are members of the species sapiens,
which includes only humans as we know them
today
Binomial nomenclature
Carl Linnaeus’ System of naming organisms
 2-word classification system for naming
organisms.
 The first word is the genus name.
 The second word is the species name.
 All scientific names are in Latin.

Binomial nomenclature

When writing an organism’s scientific name,
the genus (first word) should be capitalized
and species (second word) should be lower
case and both should be italicized or
underlined


Ex: Homo sapiens
Scientific names can also be abbreviated G.
species

Ex. H. Sapiens
The 6 Kingdoms
Kingdom descriptions
EACH SLIDE WILL FOLLOW THE FOLLOWING FORMAT:
 Number of cells
 Characteristics
 Reproduction
 Examples of Organisms

Note: Prokaryotes are simple, single-celled
organisms with no nucleus. Eukaryotes are more
complex organisms that can be either single cell or
multicellular and contain a nucleus along with
other specialized structures
Archaebacteria
Single-celled, prokaryotes
 Has cell wall but no nucleus
 Lives without oxygen in extreme
environments
 Reproduce asexually
 Ex: Methanogens, halophiles, and
thermophiles

Archaebacteria
Eubacteria
Single-celled, prokaryotes
 Has cell wall (differs slightly from wall of
archaebacteria), but no nucleus
 Reproduce asexually
 Ex: Bacteria, blue-green algae

Eubacteria
Protista
Single-celled or multicellular, eukaryotes
 Has nucleus and membrane
 May or may not have cell wall
 Can be either autotrophs or heterotrophs
 Move by cilia, flagella or pseudopods
 Normally reproduce asexually but can
reproduce sexually when under stress
 Ex: Euglenas, single-celled algae, amebas,
paramecia

Protista
Euglena
Paramecium
Amoeba
Fungi






Most are multicellular, the only single celled fungi
are yeasts, eukaryotes
Has cell wall that contains chitin, nucleus and
membrane
Made of slender strands of cells packed together
called hyphae
Heterotrophs, do not ingest their food, instead
secrete digestive enzymes onto whatever they are
growing on
Reproduce asexually and sexually
Types of fungi



Zygomycetes (bread mold)
Basidiomycetes (mushrooms)
Ascomycetes (fungi that form sexual spores)
Fungi
Yeast cells
Mushroom
Plantae






Multicellular with specialized cells and tissues.
Eukaryotes
Has cell wall made of cellulose, nucleus, membrane
and chloroplasts (the site of photosynthesis)
Autotrophs, undergo photosynthesis
Rooted to the ground so they can’t move
Reproduce either sexually or asexually
Types of plants




Nonvascular plants (mosses)
Seedless vascular plants (ferns)
Nonflowering seed plants (pine trees)
Flowering seed plants (roses, grasses and fruits)
Plantae
Flower
Moss
Fern
Green algae
Animalia






Multicellular with specialized cells and tissues,
eukaryotes
Has nucleus and membrane
Heterotrophs, undergo cellular respiration
Move using a variety of methods including walking,
running and flying
Reproduce sexually
Types of animals (99% of animals are invertebrates)






Sponges and cnidarians (jellyfish, sea anemones and coral)
Mollusks (snails, oysters and squid)
Worms (earthworms)
Arthropods (insects and spiders)
Echinoderms (sea stars, sea urchin and sand dollars)
Vertebrates (fish, mammals, birds and amphibians)
Animalia
Evolutionary History

Classification based on similarities should be based
on an organism’s phylogeny, or evolutionary
history


Remember homologous structures are evidence of a
common ancestor while analogous structures are not
Cladistics is the method of inferring relationships
based on shared characters

Ancestral character: a character that evolved from a
common ancestor


Ex: backbone in birds and mammals
Derived character: evolved in an ancestor of one group
but not another

Ex: feathers evolved in birds but non mammals
Evolutionary History

A cladogram is a branching diagram that
shows evolutionary relationships among
groups of organisms

As groups evolve, new characters appear that
were not present in earlier organisms
Cladogram
Hagfish, Perch,
salamanders, lizards
and Pigeons have
neither fur nor
mammary glands
while mice and
chimps have both
characters
Hagfish do not have jaws while every organism
Past that point on the cladogram does have jaws
Dichotomous Key




The identification of biological organisms can be greatly
simplified using tools such as dichotomous keys.
A dichotomous key is an organized set of couplets of
mutually exclusive characteristics of biological organisms.
You simply compare the characteristics of an unknown
organism against an appropriate dichotomous key. These
keys will begin with general characteristics and lead to
couplets indicating progressively specific characteristics. If
the organism falls into one category, you go to the next
indicated couplet.
By following the key and making the correct choices, you
should be able to identify your specimen to the indicated
taxonomic level.
Dichotomous Key

1)
Example: Use the Key to identify
this alien
a. The creature has a large wide
head….. Go to 2
b. the creature has a small narrow
head…. Go to 3
Narrow Head
-go to number 3
Dichotomous Key
3) a. The creature has no antennae…. Go to 4
b. The creature has antennae… Go to 5
Has Antennae
- Go to number 5
Dichotomous Key
5) a. Creature has 2 eyes… go to 6
b. Creature has 1 eye….. Narrowus Cylops
6) a. Creature has a mouth… go to 7
b. Creature has no mouth… go to 8
2 eyes
-go to 6
Mouth
-go to 8
Dichotomous Key
8) a. There are spikes on the left leg….
Narrowus portus
b. There are no spikes at all…. Narrowus
plainus
Spikes on the left leg
- Your creature is
Narrowus portus!