1. Bacteria, Protists, Algae, and Marine Plants
ENV 121 Lab

2. Tree of Life
Figure 4.24

3. Definitions: Prokaryotes:
Unicellular organisms whose cells do not have a nucleus or other organelles, simple
Eukaryotes:
Unicellular or multicellular organisms with cells possessing a nucleus and other organelles that are enclosed by membranes

4. Definitions: Nutrition:
Process by which an organism obtains from its environment
1. Energy
2. Chemical elements (carbon)
needed for its survival and growth.

5. Definitions: 1. Energy Phototroph:
organisms using sunlight as a source of energy
Chemotroph:
organisms using chemicals as a source of energy
i.e. hydrogen sulfide, ammonia, methane gas

6. Definitions: 2. Obtain Carbon molecules Autotroph:
organisms capable of synthesizing their own food from simple inorganic molecules (e.g. carbon from CO2)
Heterotroph:
organisms that obtain food from organic compounds (i.e. other living organisms) (e.g. carbon from glucose)

7. Definitions: Primary Producers
organisms that manufacture organic matter from CO2, usually by photosynthesis

8. Tree of Life
Figure 4.24

9. Domain Archaea Oldest group of organisms (3.8 billion years)
Prokaryotic cells
DNA analysis – more closely related to eukaryotes
Heterotrophs or Autotrophs
important decomposers, nitrogen fixers

10. Domain Archaea Autotrophs: “extremophiles”
Methanogens – chemoautotrophs that produce methane gas from CO2 and hydrogen gas.
Halophiles – live in high salt environments, some are photoautotrophs (performing photosynthesis)
Thermophiles – live in environments of very high
temperatures, like hot springs or near hydrothermal vents.

11. Domain Bacteria Structure: unicellular
Size ranges from 0.5 to 15 μm, among smallest living organisms
Prokaryotic cells
Shapes include: spheres, spirals, rods, and rings
Reproduction:
Simple asexual division
Generation time = 1-3 hrs.

12. Domain Bacteria Most are heterotrophs
- important decomposers, some are nitrogen fixers
- degrade pollutants
Some are Autotrophs:
Photosynthetic bacteria contain chlorophyll a
Chemosynthetic bacteria use energy released by
breakdown of ammonia, hydrogen sulfide and other sulfur or iron compounds

13. Domain Bacteria Cyanobacteria (formerly “blue-green algae”)
most primitive plant-like organisms
Photoautotrophic bacteria
Prokaryotic cells
Pigments: chlorophyll a, phycocyanin, and phycoerythrin
Important role in O2 accumulation in our atmosphere, some
carry out nitrogen fixation
Solitary or colonial
****DRAWING****

14. Domain Bacteria
Prochlorococcus
Synechococcus

15. Kingdom Protista General information:
Often separated into many different Kingdoms
Variation in cellular anatomy, ecological role, and
life cycles
Planktonic, unicellular, and multicellular
Structure:
Mostly unicellular – complex an organism as any
whole plant or animal
Size range: 0.8 to 2,000 μm (=2mm), larger than
bacteria

16. Kingdom Protista Feeding: Some are photoautotrophs  phytoplankton
Some are heterotrophs  zooplankton
Others are mixotrophs  Euglena sp.
Locomotion:
Flagella or cilia

17. Kingdom Protista Phytoplankton:
Make up ~1% of global chlorophyll biomass, but are responsible for ~50% global photosynthesis
Are the base of the oceanic food web
Regulate global climate
Sink for atmospheric CO2
Chl a Absorbance

18. Photosynthetic Protists:
Diatoms: (Class Bacillariophyta)
~ 12,000 species, half are marine
Unicellular, but aggregate
Centric (cylindrical): planktonic
Pennate (boat-shaped): benthic
Enclosed by cell walls made of
silica (SiO2)
Yellow and brown color  carotenoid pigment is fucoxanthin
Fig. 5.5

19. Photosynthetic Protists:
Diatoms
“Shell”  Frustule
light passes through holes
perforations allow gasses and nutrients
Frustules of dead diatoms  diatomaceous ooze
Important primary producers – temperate and polar regions
Can produce domoic acid
Reproduction:
Asexual = Cell division
Sexual  egg + sperm in auxospore stage
****DRAWING****

20. Photosynthetic Protists:
Dinoflagellates: (Class Dinoflagellata)
~ 1,200 species, all marine
Important primary producers –
Warm regions
Unicellular
2 unequal flagella
External cell wall armored
with plates made of cellulose or naked
Have chlorophyll, can also ingest food particles
Have Chlorophyll a, Chlorophyll c2, and peridinin
Fig. 5.7
Gonyaulax polyedra

21. Photosynthetic Protists:
Dinoflagellates
Massive blooms cause “red tides”
Some release toxins that cause shellfish
poisoning (PSP, NSP, DSP)
Some bioluminesce
Some are symbiotic to other organisms and called zooxanthellae
****DRAWING*****
Photo by DC Tulipani, 8/2003
Zooxanthellae from anemone, Bartholomea annulata

25. Photosynthetic Protists:
Coccolithophores: (Class Haptophyta)
Covered with small calcareous coccoliths
Flagellates
Major source of primary production
<20µm in diameter

26. Non-photosynthetic Protists (Zooplankton):
Foraminiferans: (Phylum Granuloreticulosa)
foramen = little hole, ferre = to bear
Planktonic protozoans (animal-like protists),
exclusively marine
Shells (tests) made of calcium carbonate
(CaCO3)
“Amoeba with a shell”
Pseudopodia
Shells of planktonic forams sink to bottom to
form foraminiferan ooze

27. Non-photosynthetic Protists:
Foraminiferans
Most live on bottom, free or attached
Important contributors in coral reefs and sandy beaches (Bermuda’s “pink” beaches)
****DRAWING****

28. http://earthguide. ucsd. edu/earthguide/imagelibrary/orbulinauniversa

29. Non-photosynthetic Protists:
Radiolarians (Phylum Polycystina)
Planktonic, marine
Secrete tests made of silica (SiO2)
Tests typically spherical with
radiating spines
psuedopodia – diatoms (Why?)
Open waters throughout ocean
Shells settle to bottom and form siliceous ooze, called radiolarian ooze
****DRAWING****
Fig. 5.11

30. Non-photosynthetic Protists:
Genus Euglena
~150 species, freshwater
Flagellum used for locomotion
Mixotrophs:
Contain chlorophyll  photosynthesize
Some eat small particles of living matter
Euglena acus
Euglena spirogyra

31. Photosynthetic Protists: Multicellular Algae
General Structure:
More complex than unicellular algae
Still lack the highly specialized structures and reproductive mechanisms of land plants
Fig. 6.1

32. Photosynthetic Protists: Multicellular Algae
Phylum Chlorophyta: “Green algae”
Contain chlorophyll a – no pigment to mask
Unicellular (3 examples - DRAWINGS)
Desmids
Volvox sp.
Cladophora sp.
Multicellular (2 examples - DRAWINGS)
Ulva sp.
Codium sp.
Ulva sp.
Codium fragile

33. Photosynthetic Protists: Multicellular Algae
Class Phaeophyta: “Brown algae”
Multicellular, mostly marine
Olive-green to dark brown color from carotenoid pigment: Fucoxanthin
Also have chlorophyll a and c
Often dominant primary producers on temperate and polar rocky shores
2 examples - DRAWINGS
Macrocystis pyrifera
Egregia sp.

34. Pelagophycus
Pelagophycus
Macrocystis
Egregia

35. Photosynthetic Protists: Multicellular Algae
Phylum Rhodophyta: “Red algae”
Essentially marine, all multicellular
Common, more species than green/brown combined
Contain red pigments called phycobilins
Most are soft bodied,
some coralline reds encrusted with hard calcium carbonate, Why?
2 examples – DRAWINGS
Corallina sp. (calcified)

36. Pelagophycus
Halimeda
Porphyra