Transcript 17-Classification (presentation)

Chapter 17 – Organizing Life’s Diversity
I.
Classification – grouping of objects or organisms
based on a set of criteria; 2 scientists
A.
Aristotle
(394-322 B.C.):
Greek
philosopher who
grouped
organisms as
either plants or
animals
B.
Carolus Linnaeus (1707-1778) – Swedish
naturalist who grouped organisms based
on morphology, behavior, & habitat
1.
II.
Taxonomy – branch of Biology where
species are identified, named, &
classified based on natural
relationships
Binomial Nomenclature – a system that gives
each species a scientific name that has 2 parts
A.
1st part:
genus name; capitalized
2nd part:
specific epithet/name;
it IDs the species; lowercased
B.
Writing Scientific names
1.
italicized when typed: Homo sapiens
2.
in handwriting:
Homo sapiens
C.
Latin is the language of Binomial
Nomenclature – why?
 It is no longer used in conversation
and, therefore, does not change
D.
Common names are confusing & vary in use
1.
2.
3.
A starfish isn’t a fish
A sea horse is a fish, not a horse
Sea cucumbers are not plants
III.
Taxonomic Categories – these are a nested,
hierarchical system, where each category is
contained within another from broadest to most
specific
A.
The broader the characteristics, the more
species the taxon contains
1.
Species – smallest taxon; organisms that
are able to interbreed & produce fertile
offspring in a natural setting
2.
Genus – group of species that are closely
related & share a common ancestor
3.
Family – group of similar, related genera
(plural of genus)
4.
Order – group of related families
5.
Class – group of related orders
6.
Phylum / Division – group of related classes
7.
Kingdom – group of related phyla/divisions
8.
Domain – largest taxon; group of related
Kingdoms
B.
Example in Humans:
Taxon
Name
Shared with?
D-Dear
Eukarya
all other organisms w/ nuclei &
organelles in their cells
K-King
Animalia
all other animals
P-Phillip
Chordata
with a spinal cord
C-Came
Mammalia
O-Over
Primate
F-For
G-Good
S-Spaghetti
hairy; young are fed milk
opposable thumbs
Hominidae primates w/ social skills &
complex intelligence
Homo
all humans, including those
that are extinct
sapiens
us – the only humans alive
C.
Dichotomous Key – a key made up of sets
of numbered yes/no statements
1.
Has green colored body ......go to 2
Has purple colored body ..... go to 4
2.
Has 4 legs .....go to 3
Has 8 legs .......... Deerus octagis
3.
Has a tail ........ Deerus pestis
Does not have a tail ..... Deerus magnus
4.
Has a pointy hump ...... Deerus humpis
Does not have a pointy hump.....go to 5
5.
Has ears .........Deerus purplinis
Does not have ears ......Deerus deafus
IV.
Phylogeny – the evolutionary history of a species,
based on characters (inherited, varied features)
A.
Morphological – similar parts suggest a
relationship
beaks of Galapagos
finches

bones in vertebrate
limbs

B.
Biochemical – similar amino acids &
nucleotides in DNA suggest a relationship
1.
Cauliflower & Broccoli
look different, but have
almost identical DNA
(mustard)
C.
Cladogram – a branching diagram that
represents the proposed phylogeny or
evolutionary history of a species or group
D.
The 3 Domains w/ 6 Kingdoms – differ in cell
type & structure (pg. 502)
Bacteria
 Archaea
Eukaryotes
 Eukarya
Kingdom
Characteristics
 (Eu)Bacteria cell walls w/ peptidoglycan,
unicellular
 Archaea(bacteria) cell walls w/o PG, unicellular
Autotrophs OR Heterotrophs
Prokaryotes
Domain
 Protista
cell walls w/ cellulose in some,
unicellular or multicellular
 Fungi
cell walls w/ chitin,
mostly multicellular, heterotrophs
 Plantae
cell walls w/ cellulose,
multicellular, autotrophs
 Animalia
no cell walls, multicellular,
heterotrophs
Evolution of the 6 Kingdoms of Life
Newer,
More
Complex
Plantae
Animalia
Fungi
Protista
Bacteria
Archaea
Older,
Less
Complex
Common
Ancestor
The 6 Kingdoms of Life