1. Prokaryotes and “Kingdom Protista”

2. Domain Bacteria Domain Archae
The Prokaryotes
Domain Bacteria Domain Archae

3. Cell type: Prokaryotes
Found in:
Domain Bacteria
Domain Archaebacteria

4. Cell type: Prokaryotes
Two Domains: Bacteria and Archae
Do not have a membrane bound nucleus
Very few organelles, if any
Smallest and structurally simplest living organisms.
Oldest forms of life on earth
Microscopic
Circular shaped DNA molecules
Shapes: rod, spherical or spiral

5. Metabolism Autotrophic -photosynthetic -chemosynthetic Heterotrophic
-aerobic respiration (with oxygen)
-anaerobic respiration (without oxygen)
ex: use SO4-2 instead of oxygen
(Anoxic: environment without oxygen)

6. Domain Bacteria Unicellular; some form colonies.
Cell wall of peptidoglycan
Essential role in nutrient cycles
Major groups: decay bacteria, cyanobacteria, nitrifying bacteria, pathogenic bacteria

7. Domain Bacteria: Decay Bacteria
Break down waste products and detritus
Detritus: dead organic matter
Release nutrients into the environment
Importance: recycling of essential nutrients

8. Domain Bacteria: Cyanobacteria
Also known as blue-green algae
Photosynthetic
Photosynthetic Pigments
-Contains chlorophyll a (pigment in plants)
-Phycocyanin: bluish pigment
-Phycoerythrin: reddish pigment
-Dominant pigment determines color

9. Domain Bacteria: Cyanobacteria
Stromatolites: Thought to have an important role in the accumulation of oxygen in earth’s atmosphere
Prochlorococcus: thought to be most abundant photosynthetic organism in the ocean
Red tides: bloom of cyanobacteria with red pigment (can cause skin rashes)

10. Prochlorococcus

11. Oscillatoria

12. Spirulina and Oscillatoria

13. Anabaena

14. Domain Bacteria: Nitrifying Bacteria
Carry out nitrogen fixation
-converting nitrogen gas into ammonium which is then converted into nitrates.

15. Domain Archae
Used to be classified with Bacteria but are now thought to be closer related to eukaryotes.
Extremophiles: found in extreme environments (acid pools, hot springs, hydrothermal vents, etc…)
Methanopyrus: methanogen living near hydrothermal vents
Common throughout the ocean not just extreme environments

16. Domain Eukarya “Kingdom Protista”
The Eukaryotes
Domain Eukarya “Kingdom Protista”

17. Cell type: Eukaryotes
Have a membrane bound nucleus and complex organelles.
Found in Domain Eukarya
Includes Kingdoms: “Protista,” Fungi, Plantae, Animalia

18. “Kingdom Protista” Domain Eukarya
So diverse a kingdom, that many scientists don’t consider it a true kingdom anymore
Divided into two general groups:
Algae: plant-like protists.
Protozoans: animal-like protists.

19. Characteristics of Algae (plant-like protists)
Eukaryotic (nucleus!)
Can be unicellular or multicellular
Mostly photosynthetic (have chloroplast)
Contain cell walls (many different kinds)
a.k.a. phytoplankton
Our Focus now: unicellular (i.e. single cell)

20. DIATOMS Phylum Bascillariophyta
Algae
(plant-like protists)
“golden algae”
carotenoid pigments (such as xanthophyll = yellow pigment)
chlorophyll a and c
Classified according to shape
Centricae: round
Pennatae: pen-shaped
Buoyancy
Need to float near the surface to absorb sunlight
Adaptations to help prevent sinking by decreasing density:
Radiating spines
Oil droplets (lipids)

21. DIATOMS Phylum Bascillariophyta
Algae
(plant-like protists)
Cell Wall
made of silica (main ingredient of glass).
Has tiny pores to allow for exchange of materials.
Also called frustule or test.

23. Diatoms

24. (plant-like protists)
DIATOMS Phylum Bascillariophyta
Algae
(plant-like protists)
Reproduction
Asexual: fission; two frustules separate and each half secretes a new frustule to complete the formation of the new diatom.
Sexual: diatom develops into a male or female. Male releases sperm and enter the female diatom where it unites with an egg. The fertilized egg develops into a mature diatom.

27. (plant-like protists)
DIATOMS Phylum Bascillariophyta
Algae
(plant-like protists)
Blooms
Occur in favorable conditions such as adequate nutrition and light
Normally spring and fall due to overturn (upwellings)
Some contain a toxin called domoic acid that can build up in plankton eating organisms Both shellfish and fish can accumulate this toxin without apparent ill effects; however, in humans the toxin crosses into the brain and interferes with nerve signal transmission. People poisoned with very high doses of the toxin can die, while lower doses can cause permanent brain damage (short term memory loss).

28. (plant-like protists)
DIATOMS Phylum Bascillariophyta
Algae
(plant-like protists)
Diatomaceous Earth
Dead diatom frustules fall to ocean floor
Form a thick deposit of siliceous material
Biogenous sediment: a.k.a. diatomaceous ooze
Used in many industries; good for filtering (swimming pools, drinking water, clarifying beer) and a good mild abrasive (toothpaste and polishers)

29. (plant-like protists)
DIATOMS Phylum Bascillariophyta
Algae
(plant-like protists)
Ecological Importance
Basis of the food chain in both marine and freshwater environments
Consumed by tiny invertebrates called copepods who are eaten by fish
Shellfish consume diatoms by filtering them out of the water

30. DINOFLAGELLATES Phylum Dinophyta
Algae
(plant-like protists)
Unicellular
Planktonic
Two flagella
Cell wall made of plates of cellulose
Autotrophic and heterotrophic
Eyespot: detect light

32. DINOFLAGELLATES Phylum Dinophyta
Algae
(plant-like protists)
Flagella
Used in locomotion
One trails free
One wrapped around a groove along the middle of the cell

35. DINOFLAGELLATES Phylum Dinophyta
Algae
(plant-like protists)
Reproduction and Blooms
Almost exclusively asexual (fission)
Red Tide: caused by Gymnodinium (contains a red pigment)
Gonyaulax: produces a neurotoxin that causes paralytic shellfish poisoning that can lead to illness and death in fish and humans.

36. Red Tide (Gymnodinium)

38. Gymnodinium

39. DINOFLAGELLATES Phylum Dinophyta
Algae
(plant-like protists)
Some are bioluminescent :produces light (Pyrodinium)
Zooxanthellae: round, golden brown dinoflagellates that live in close association with a variety of animals
Sponges
Corals
Sea anemones
Giant clams

40. Bioluminescent Dinoflagellate

41. Characteristics of Protozoans (animal-like protists)
Structurally simple and very diverse
Most are unicellular
Heterotrophs
Some are also photosynthetic
Marine and freshwater as well as inside other organisms

42. FORMANIFERANS Phylum Granuloreticulsa
Protozoans
(animal-like protists)
Called forams
Marine
Have tests (shells) of calcium carbonate (CaCO3)
Pseudopodia: extension of cytoplasm that protrude through pores; trap food
Benthic or planktonic

43. (animal-like protists)
Protozoans
(animal-like protists)

44. (animal-like protists)
Foraminiferan Ooze
Protozoans
(animal-like protists)
Calcareous ooze
Create limestone and chalk beds
Biogenous ooze

45. (animal-like protists)
Protozoans
(animal-like protists)

46. RADIOLARIANS Phylum Polycystina
Protozoans
(animal-like protists)
Planktonic, marine
Delicate shells of silica with radiating spines
Needle-like pseudopodia that capture food
Radiolarian ooze

47. (animal-like protists)
Protozoans
(animal-like protists)

48. (animal-like protists)
Protozoans
(animal-like protists)

49. CILIATES Phylum Ciliophora
Protozoans
(animal-like protists)
Protozoans with cilia
Cilia: hair-like and used in locomotion and feeding
Planktonic or benthic
Live on the gills of clams, intestines of sea urchins or on the skin of fish
Paramecium: most common freshwater forms

50. (animal-like protists)
Protozoans
(animal-like protists)