1. Prokaryotes
2. Bacteria
3. Eukaryotes
4. Fungi
5. Protozoans
6. Unicellular Algae

Prokaryotes

1. Small and simple cells
2. Surrounded by a plasma membrane and cell wall
3. DNA as a single molecular loop
4. Definition: Prokaryotes have tiny cells without a membrane bound nucleus or specialized, membrane bound organelles.

Bacteria

1. A diverse group of prokaryotic organisms
2. Unicellular or cell aggregates
3. Found in very large numbers in every habitat
4. Carry out many types of biochemical reactions
5. Important in recycling elements in ecosystems

 

Types of Bacterial Metabolism

1. Definition: Metabolism is the sum total of all biochemical reactions in an organism or cell
2. Metabolic types: Heterotrophs and Autotrophs

Bacterial Heterotrophs

1. Definition: Heterotrophs consume premade food
2. Definition: Decomposers absorb organic molecules and may preceed absorption with external digestion

Bacterial Autotrophs

1. Definition: Autotrophs produce food from inorganic molecules
2. Definition: Photoautotrophs use sunlight as an energy supply (ex. Cyanobacteria which are photosynthetic and fix nitrogen, converting nitrogen gas (N₂) to ammonia (NH₃))
3. Definition: Chemoautotrophs use inorganic chemicals as energy supply

Habits of Bacteria

1. Benthic: greatest numbers associated with surfaces of sediment grains or detrital particles
2. Planktonic: free floating or attached to detritus

Eukaryotes

1. Large and complex cells
2. Contain various membrane bound organelles that carry out specific functions within the cell
3. DNA organized into chromosomes
4. Definition: Eukaryotes have large cells with a membrane bound nucleus and specialized, membrane bound organelles.

Levels of Organization

1. Eukaryotic organisms may be unicellular, cell aggregates, or multicellular
2. The cells of multicellular organisms have a division of labor with cells specialized to perform various functions
3. At the cellular level of organization each cell is more or less independent of the others
4. At the tissue level of organization cells are organized into interacting groups called tissues that perform specific functions
5. At the organ level of organization various tissues are organized into structures called organs that perform specific functions
6. At the system level of organization various organs are organized into groups called organ systems that perform specific functions

Marine Fungi

1. One percent of fungal species are marine
2. Marine fungi are all small in size
3. Yeasts and molds: Unicellular, cell aggregates, or multicellular

Types of Fungal Metabolism

1. Decomposers with external digestion
2. Symbionts (ex. Lichens consist of fungi and cyanobacteria or algae in a symbiotic relationship)

Habits of Fungi

1. Benthic

Protozoa (Animal-Like Protists)

1. Unicellular eukaryotes
2. Heterotrophs
3. Decomposers with external digestion or ingesters with internal digestion

Foramenifera

1. Calcareous shells
2. Shells acumulate on seafloor to form oozes
3. Psuedopods for feeding
4. Benthic or planktonic

Radiolarians

1. Siliceous shells
2. Shells accumulate on the seafloor to form oozes
3. Psuedopods for feeding
4. Planktonic

Algae (Plant-Like Protists)

1. Unicellular to multicellular eukaryotes
2. Autotrophs
3. Photosynthetic containing chlorophyll

Diatoms

1. Siliceous shells
2. Pillbox shape
3. Shells accumulate to form oozes
4. Unicellular, chains or clusters
5. Move by gliding
6. Golden brown color
7. Most abundant in cool waters
8. Benthic or planktonic

Silicoflagellates

1. Siliceous cell wall
2. Unicellular
3. Move with flagella
4. Golden brown color
5. Important in tropics
6. Planktonic

Dinoflagellates

1. Cellulose cell wall
2. Unicellular
3. Move with flagella
4. Planktonic
5. Red Tide is a bloom of dinoflagellates of tremendous proportions

Dinoflagellate Defenses

1. Defenses against predators
2. Neurotoxins cause fish kills & paralytic shellfish poisoning
3. Biolumenescence is the biological production of light. It is triggered mechanically and is used as a startle defense.

Coccolithophores

1. Calcareous shells of stony buttons
2. Unicellular
3. Non-motile
4. Regionally important as in Meditteranean Sea
5. Planktonic