Transcript Classification Notes

Classification System Notes
June 2, 2016
Domains

All of the organisms in the world are
assembled into three domains:
1. Archaea (archaebacteria)
2. Bacteria (eubacteria)
3. Eukarya (eukaryotes)
The Archaea (archaebacteria)

Archaea have the following characteristics:
◦ Prokaryotic cells
◦ Have membranes composed of branched
hydrocarbon chains attached to glycerol
by ether linkages
◦ Cell walls contain no peptidoglycan
◦ Not sensitive to some antibiotics that
affect the Bacteria, but are sensitive to
some antibiotics that affect the Eukarya

Habitat:
◦ Often live in extreme environments
 Include methanogens, extreme
halophiles, and hyperthermophiles
 Ether-containing linkages in the
membranes are more stable than in
the Bacteria & Eukarya
 Are better able to withstand higher
temperatures & stronger acid
concentrations
The Bacteria (eubacteria)

Bacteria have the following characteristics:
◦ Prokaryotic cells
◦ Have membranes composed of
unbranched fatty acid chains attached to
glycerol by ester linkages
◦ Cell walls of Bacteria contain peptidoglycan
◦ Sensitive to traditional antibacterial
antibiotics but are resistant to most
antibiotics that affect Eukarya

Bacteria include:
Mycoplasma
Cyanobacteria
Gram-negative
bacteria
Gram-positive
bacteria
The Eukarya (eukaryotes)

Eukarya have the following characteristics:
◦ Eukaryotic cells
◦ Membranes composed of unbranched fatty
acid chains attached to glycerol by ester
linkages
◦ Not all possess a cell wall, but for those
having a cell wall, it contains no peptidoglycan
◦ Resistant to traditional antibacterial
antibiotics but are sensitive to most
antibiotics that affect eukaryotic cells
The Eukarya are subdivided into 4
kingdoms
1.
2.
3.
4.
Protista Kingdom
Fungi Kingdom
Plantae Kingdom
Animalia Kingdom
Protista Kingdom
Simple, predominately unicellular
eukaryotic organisms
 Examples include slime molds, euglenoids,
algae, & protozoans

Fungi Kingdom
 Fungi
are unicellular or multicellular
organisms with eukaryotic cell types
 Have cell walls but are not organized
into tissues
 Do not carry out photosynthesis
 Obtain nutrients through absorption
 Examples
include
◦ Sac fungi
◦ Club fungi
◦ Yeasts
◦ Molds
Plantae Kingdom
Multicellular organisms composed of
eukaryotic cells
 Cells are organized into tissues
 Have cell walls
 Obtain nutrients by photosynthesis and
absorption

 Examples
◦ Mosses
◦ Ferns
◦ Conifers
◦ Flowering plants
Animalia Kingdom
Multicellular organisms composed of
eukaryotic cells
 Cells are organized into tissues
 Lack cell walls
 Do not carry out photosynthesis
 Obtain nutrients primarily by ingestion

 Examples
include
◦ Sponges
◦ Worms
◦ Insects
◦ Vertebrates
Viruses? Living or Nonliving?
Viruses are not part of the classification
scheme because they are nonliving
particles
 Consist of a protein capsid, nucleic acid,
etc… that require a living host in order
to reproduce
