Transcript Honors Biology Chapter 18 Lecture

Taxonomy and Classification
Honors Biology
2010
15.15 and 15.19 Systematics
16.1 and 16.2 Bacteria and
Archaea
16.11 Protists
17.1 Plants
17.14 Fungi
18.1 Plants
Important Root Words
ROOT WORD
MEANING
morph-
form, shape
-nomy
law, science
taxo-
biarchaeeu-
prokaryophylo-gen
nomen-
order, arrangement
two
ancient, old
good, true
before
nucleus
tribe
to produce
name
Early Systems of Classification




Systematics: the field of biology that focuses on classification
and grouping organisms based on their evolutionary relationships
Taxonomy
 Naming
 Describing
 Classifying
Classification
 Grouping organisms by their similarities or relationships
Aristotle
 First to classify organisms 2,000 years ago
 Classified organisms as either plant or animal
Levels of Classification

Methods used to classify organisms



Phylogeny: relatedness among organisms based on
evolutionary history
Morphology: using appearance, form or structure to
determine relationships
Taxonomic categories








Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Binomial Nomenclature

Scientific Name

Genus + specific epithet
Homo sapiens
 Quercus alba



Odontotaenius disjunctus
Linnaeus, mid-18th century
Facilitates international science
Armadillidium vulgare
Classification Video
Using Dichotomous Keys





A device that can be used to easily identify an unknown
organism.
A dichotomous key consists of a series of two part
statements that describe characteristic of organisms.
At each step of a dichotomous key the user is presented
with two choices.
As the user makes a choice about a particular
characteristic of an organism they are led to a new branch
of the key.
Eventually the user will be led to the name of the organism
they are trying to identify.
Comprehension Check
Homo sapiens : Homo neanderthalis ::
a. Melanoplus darwinian : Ulna darwinian
b. Red Oak : White Oak
c. Acer rubrium : Acer sacharus
d. Anolis carolinenins: Turdus migratoria
The Six Kingdoms

Based on cell structure &
nutrition
The Three Domains

Based on molecular differences

Archaea


Eubacteria


Lack simple RNA polymerase (enzyme needed
for making proteins)
Peptidoglycan in cell walls
Eukarya

Eukaryotes
The Three Domains Video
Bacteria Domain





Unicellular
Prokaryotic Cells
Cell walls made of
peptidoglycan
Very diverse group
including free living
organisms and deadly
parasites
Some can
photosynthesize, some
can not
Archaea Domain





Unicellular
Prokaryotic
Live in extreme
environments
Most will be killed
by oxygen
Some can
photosynthesize/
chemosynthesize,
some can not
Eukarya Domain



Some unicellular, but most are multicellular
All have cells with a nucleus
4 Sub-groups (Kingdoms)




Protista: things that can not be classified as plant,
animal or fungi
Fungi: Secrete digestive enzymes into their food
Plant: Photosynthesizers
Animals: Heterotrophs, high amount of diversity
Comprehension Check
You discover a new organism that has RNA
polymerase, but does not have peptidoglycan
in it’s cell wall.
• What domain does it belong to? How can
you tell?
• Can you figure out what Kingdom it belongs
in based solely on this information? Why
or why not?