Linking Form to Function

Question 1

Cyanobacteria

Answer 1

Prokaryotes (1-10um)
No cellular bound organelles
Cellulose cell wall
Chlorophyll a and phycobilin
Some contain gas vacuoles
Some (mostly freshwater forms) have heterocyst for N fixation

Question 2

Prochlorococcus

Answer 2

Unicellular prokaryotic
Chlorophyll (divinyl) a and b
Can be detected with a flow cytometer, not visible under a microscope

Question 3

Synechococcus

Answer 3

Uniceullar prokaryote
Chlorophylla, phycoethryn, zeaxanthin
Can be detected with a flow cytometer, not easily visible under a microscope

Question 4

Distributions

Answer 4

Prochlorococcus dominates in low latitude, warm, nutrient poor waters.
Synechococcus more abundant at edges of lowest nutrient water.
Both are characterized by a wide genetic diversity
Different ecotypes occupy different niches

Question 5

Trichodesmium

Answer 5

Can form intense blooms in some oligotrophic tropical waters.
Filamentous cyanobacteria N fixation
Gas vacuoles provide buoyancy
Grow in trichomes clumped together as colonies
Distribution mapped using VPR

Question 6

Diatoms

Answer 6

Unicellular or loose colonies
No flagella, Si cell wall.
Frustule in halves, upper epitheca (large) and lower hypotheca (small)
Contain fucoxanthin, brown pigment colour and chlorophyll c.
Abundant in high latitudes and coastal systems

Question 7

Diatom Division

Answer 7

Cells decrease in size following each asexual reproduction cycle.
Sexual reproduction occurs on reaching minimum size.

Question 8

Centric diatoms

Answer 8

Discoid form
Skeletonema costatum.
Coastal centric chain forming diatom.
Frustules joined by Si spines

Question 9

Pennate diatoms

Answer 9

Linear Form
Fragilariopsis kerguelensis
- Sern Ocean chain forming.
Pseudo nitzchia
- common open ocean diatom, some toxic

Question 10

Silica Frustule

Answer 10

Defense against grazing
Also dense, so dead cells sink quickly

Question 11

Haptophytes or Prymnesiophytes

Answer 11

Unicellular or colonial usually motile
Reserve products lipids
2 or sometimes 4 chloroplasts
Contain chlorophyll a and c and 19 hexanoxylfucoxanthin.

Question 12

Coccolithophores

Answer 12

Calcium carbonate platelets
Some naked species
* 2HCO3 - + Ca2+ → CO2 + H2O + CaCO3
Blooms often abundant in high latitudes and coastal systems

Question 13

Phaeocystis blooms

Answer 13

Individuals or colonies
Some coastal or high latitude blooms
Foam can be problematic

Question 14

Dinoflagellates

Answer 14

Mostly unicelluar, some chains
Paired flagella
Thecate or cell wall covered in cellulose plates or naked (athecate)
Chloroplasts yellow green or tallow brown, diverse pigments
Many taxa can be toxic or harmful
Blooms = red tides

Question 15

Dinoflagellate species

Answer 15

Symbiodinium spp
- Endosymbionts living in edoderm of corals, sea anemones, sponges, foraminifera
Ceratium spp
- Important primary producers in some coastal systems

Question 16

Flaggelated Euks (chlorophyta)

Answer 16

Green algae
Micro and macro examples
Chlorophyll a and b
Cellulose in cell wall
Starch as storage product

Question 17

Euglenaphyta (Euglenoids)

Answer 17

Ovoid unicellular
Chlorophyll a and b
1 or 2 flagella

Question 18

Cryptophyta

Answer 18

Small unicellular ovoid or slipper shapped
2 flagella
Contractile vacuole
2 chloroplasts
contain chlorophyll a and c plus phycobilins

Question 19

Further symbioses

Answer 19

Endosymbiotic cryptophyte inside a protozoan ciliate host.
Photosynthesises until digested, not a permanent endosymbiosis yet
Most mobile single cells marine photosynthetic microorganisms.