1. Part 3 Classification and Biodiversity
Ch. 18
Part 3
Classification and Biodiversity

2. Largest hierarchy of classification is DOMAIN
System for biologists to arrange organisms into groups
Categories = easier to remember
Taxonomy
Study and practice of classification
Involves placing organisms into a series of taxonomic units called TAXA which form a hierarchy
Each different organism is assigned a SPECIES
Similar species are grouped into the same GENUS
Similar GENERA (plural) are grouped into FAMILIES
Similar families are grouped into ORDERS
Similar orders are grouped into CLASSES
Similar classes are grouped into PHYLUMS
Similar phylum are grouped into KINGDOMS
Largest hierarchy of classification is DOMAIN

3. So how do we classify???
Domain - Eukarya

4. Domains Broadest category of classification 1970’s
Scientists needed a new category to distinguish between extremophiles and normal bacteria
Three main domains
Domain Archaea:
unicellular prokaryotes that live in extreme environments (very hot or very cold, extremely acidic or basic)
Extremeophiles
Domain Bacteria: All other unicellular prokaryotes
Domain Eukarya: Organism made up of eukaryotic Cells
Includes 4 kingdoms: Protists, Fungi, Plants, Animals (and Monera)

6. Still some confusion among scientists over this one…

8. Consists of 1 MAJOR Kingdom
Archaeabacteria
Domain Archaea
Extremophiles
Currently, there are some living in less extreme areas of the ocean
Prokaryotic
More in common with Domain Eukarya than
Genes coding for ribosomes very similar to those genes found in eukaryotes Domain Bacteria
No nucleus
Size similar to bacteria
No membrane-bound organelles
DNA is circular chromosome WITH histones present
Contain Plasmids
70S ribosomes
Smaller than eukaryotes 80S ribosomes, BUT similar structure to eukaryotic ribosomes
Cell wall ALWAYS present (not made of peptidoglycan)
Divides by BINARY FISSION
Exist as single cells or groups of cells
Similar metabolism to normal bacteria
Transcription similar to eukaryotic transcription

9. Consists of 1 MAJOR Kingdom
Domain Bacteria
Prokaryotic (no nucleus)
Small size 0.5 to 5 um in diameter
Range between largest virus and smalled eukaryote
DNA is circular chromosome with NO histones
Plasmids present
No membrane-bound organelles present
70S ribosomes
Cell wall always present
Contains peptidoglycan NOT cellulose
Divides by binary fission
Exists as single cell or groups of cells
Consists of 1 MAJOR Kingdom
Eubacteria

10. Domain Eukarya Cells contain a nucleus Membrane-bound organelles
DNA arranged in LINEAR chromosomes WITH histones
80S ribosomes
Mitochondria and chloroplasts 70S ribosomes
Chloroplast and mitochondrial DNA is circular
Great Diversity in how they exist
Unicellular
Colonial
multicellular
Cell division by MITOSIS
Asexual and Sexual reproduction
Consists of 4 MAJOR Kingdoms
Protoctista
Fungi
Plantae
Animalia

11. Kingdom Protoctista Any eukaryote that is not fungi, plant, or animal
Consists of wide range of organisms
PROTOZOANS (simple animals)
Similar to animal cells
NO cell wall
ALGAE (seaweeds)
Similar to plant cells
Have cell wall and chloroplasts
Strong argument to classify these as PLANTS
Single-celled
Exists as single cell or group of cells

12. Kingdom Fungi All heterotrophic
Use organic compounds made by other organisms for energy source
Decomposers  energy obtained from dead and decaying organism
Parasitic  feed on host
Confused with plants b/c they are NON-MOTILE
Wide range in size (some microscopic)
Eukaryotic
NO chlorophyll and do NOT use photosynthesis
Reproduce by SPORES
Simple body forms
Unicellular
HYPHAE  long threads with or without cross walls
Compacted hypahe make up larger body forms like mushrooms
Contain cell walls made of CHITIN
NO cilia or flagella

13. Kingdom Plantae ALL multicellular ALL photosynthetic (AUTOTROPHIC)
Differentiated tissues and organs
ALL photosynthetic (AUTOTROPHIC)
Eukaryotic (nucleus)
Complex bodies
Above ground
Branched
Few types of specialized cells
SOME cells have chloroplasts and use photosynthesis
Cells contain LARGE, permanent vacuoles for SUPPORT
Cell walls made of CELLULOSE May have flagella
Male gametes in some types of ferns

14. Kingdom Animalia Eukaryotic (nucleus) ALWAYS MULTICELLULAR
Differentiated and specialized cells
Differentiated into tissues and organs
ALL Heterotrophic
Contain NERVOUS SYTSEM
Important in communication
Do NOT have chloroplasts and cannot use photosynthesis
Exception: some coral polyps with protoctists living in tissues
Small, temporary cell vacuoles (exocytotic vacuoles, food vacuoles, lysosomes)NO cell walls
Cells sometimes have cilia and flagella

15. Viruses Microorganisms
Range in size from nm (50x smaller than average bacteria)
Visible with electron microscope
NO cell structure
No membrane
No cytoplasm
No ribosomes
Consist solely of:
Self-replicating DNA or RNA molecule
Protective coat of proteins
Capsid  protein coat
Capsomere  proteins embedded in capsid
When free in environment:
They are infectious
No metabolism
Must use machinery of host cells to copy their genetic material
Use energy from host cell to do these things
Taxonomic classification
Based on diseases that viruses cause
Type of genetic material they contain

16. DNA RNA Types of Viruses Nucleic Acid Example Host Disease 1 2
Number of Strands
Example
Host
Disease
DNA 1
Canine parvirus type 2
Dogs
Canine parvovirus
African mosaic virus
Cassava plants
Mosaic virus 2
Varicella zoster virus (VZV)
Humans
Chicken pox
RNA
Rotavirus
Gastroenteritis
Morbillivirus
Measles
Tombaco mosaic virus (TMV)
Tomato, tobacco, pepper
Mosaic disease
HIV/AIDS