Systematics

- the study of diversity and their ancestral relationships

Taxonomy

the science of naming, describing and classifying organisms

Classification

ordering of organisms into groups based on similarities and phylogeny

Criteria for Classification (6)

1. Morphology

2. Embryonic Development

3. Fossil Record

4. Ecology

5. Molecular Evidence

6. Biogeography

Morphology

- study of body structures (anatomy)

Ecology

study of relationships with other species and within populations

A.  Each species has a two-part name

B.  Species are organized hierarchically into broader and broader groups

Genus

: the closest group to which a species belongs

Specific Epithet

: refers to one species within each genus

Eubacteria

- Prokaryotes (no nucleus or organelles)

- unicellular

- cell walls made of peptidoglycan

- decomposers (some parasitic, some autotrophs)

Archaebacteria

- Prokaryotes

- Unicellular

- NO peptidoglycan in cell walls

- biochemical differences from eubacteria

- live in oxygen free environments

- Eukaryotes

-mainly unicellular or simple multicellular

- three informal groups : protozoa, algae, and water and slime molds

Fungi

- Eukaryotic

-heterotrophic

- made of hyphae

- cell walls of chitin

- decomposers

EX: Yeast, mushrooms

Plantae

- eukaryotes

- multicellular

- tissue differentiation

-photosynthetic

-cell walls of cellulose

-primary producers

-alternation of generations

Animalia

- eukaryotes

- multicellular

- heterotrophic

- tissue differentiation and complex organ systems

- specialized nervous tissue

- consumers

- determinate growth

Virus

virus structure (3)

1. nucleic acid core

2. protein capsid

3. envelope

Difference between DNA and RNA viruses

DNA virus requires transcription and translation

RNA requires translation only

Lytic Virus Lifecyle (5 steps)

1. virus "attaches" to cell receptors

2. DNA or RNA "penetrates" the cell membrane

3. Uses viral DNA or RNA to replicate the virus (biosynthesis)

4. Viruses "mature" inside of cell

5. Cell bursts and "releases" viruses to attack other cells

Lysogenic Viral Lifecycle (3) and 2 examples

1. Virus enters the cell and splices its DNA into the cells DNA

2. Stimulated at some other time it forces the cell to produce viruses from its prophage (virus genetic code)

3. Cell later enters lytic cycle and releases viruses to attack other cells

EX: Herpes and HIV

Bacteriophage

viruses that attack bacteria

Types of Bacteria:

- Coccus

- Diplococcus

- Tetrad

- Staphylococcus

- Streptococcus

- Bacillus

- Spirillum

- Spirochete

- Spheres

- Pairs of spheres

- Group of 4 cocci

- Cluster of cocci

- Chain of cocci

- rod-shaped

-  fixed spiral shaped

- flexible spiral shaped

Domain Archaea

- primitive tolerant anaerobic species

- Methanogens

- Halophiles

- Thermoacidophiles

Cyanobacteria

blue- green algae

- all groups of photosynthesizing bacteria

- 1st photosynthesizing cells on earth

- Heterocysts allow Nitrogen fixation (n2 to NH3)

ex: Nostoc and Anabaena

Nitrogen - Fixing Bacteria

- EX: rhizobia

- forms nodules on plant roots

- converts nitrogen gas in the soil to ammonia

- produces plant proteins

Gram Stain

Gram Positive

- simpler cell walls

- large amounts of peptidoglycan

- stains purple

Gram Negative

- more complex cell walls

- less peptidoglycan

- stains red

- more difficult to kill

Antibiotics

- inhibit the synthesis of cross links in peptidoglycans

- may inhibit DNA or RNA synthesis

- Resistance occurs rapidly due to short generation time and genetic variation

Capsule

- sticky protective layer on outside of cell wall

- adheres the cells to their substratum

- may increase resistance to host defenses

-helps regulate osmotic pressure in cyanobacteria

Exotoxins

poisons that are secreted by the bacteria or leak out when the bacterium dies

EX: E. coli

Endotoxins

components of the cell wall of most gram positive bacteria

(not destroyed by heat)

EX: Salmonella

Viroid

Diplomonads

- single celled protozoans

- 2 nuclei and 2 sets of flagella

- all members lack mitochondria

- EX: Giardia in polluted water

Parabasalids

-single celled protozoans

- 4 flagella and an undulating membrane

- all members lack mitochondria

EX: Trichomonas - STD

Trichonympha - gut of termites

Euglenids

-flagellated freshwater unicellular

- flexible protein pellicle

- light sensing stigma

-photo-heterotroph

- some with chloroplasts, all with mitochondria

-reproduce by mitosis

Kinetoplastids

- single celled, flagellated protozoans named for their kinetoplasts (large masses of DNA found in single mitochondrion)

- EX: Trypanosoma - African Sleeping Sickness transmitted by Tse Tse fly

Dinoflagellates

- bounded by protective cellulose plates

- 2 flagella

- important source of ecosystem food

- reproduce asexually by mitosis

- cause red tide