Lecture 13 - DA Flashcards
What were the earliest photosynthetic organisms?
Cyanobacteria.
Are cyanobacteria prokaryotic or eukaryotic?
Prokaryotic.
What two pigments do cyanobacteria use?
Chlorophyll a, and phycobillins.
What storage molecules do cyanobacteria use?
Gylcogen.
What cell wall do cyanobacteria have?
Peptidoglycans and lipopolysaccharides.
What kind of vacuole do cyanobacteria have, what what does this lend them?
Gas vacuole, allowing them to maintain buoyancy.
Are cyanobacteria able to fix nitrogen?
Yes.
How do cyanobacteria reproduce?
Binary fission.
What kind of water pH do cyanobacteria like and dislike?
Alkali or neutral. Dislike acidic.
Do cyanobacteria thrive with turbulence?
No, it can kill them.
What two nutrients do cyanobacteria need to bloom?
Phosphates and nitrates.
Do cyanobacterial blooms occur when P and N levels are minimal?
Yes, to luxury consumption and storage when nutrients are plentiful.
What 6 factors affect cyanobacteria buoyancy?
Gas vacuole synthesis Cell turgor pressure Carbohydrate load P limitation Turbulence Light intensity
What does toxin production depend on? The deficiency of which two elements will cause toxicity?
Depends on environmental conditions.
Low C and N cause toxicity.
Does toxin production equal bloom biomass? Do all blooms cause toxicity?
Toxin production doesn’t equal bloom biomass
Not all blooms cause toxicity
Do toxin producing strains of cyanobacteria always produce toxins?
No.
What are the two main types of toxins produced by cyanobacteria?
Neurotoxins
Hepatotoxins
Are neurotoxins easily degraded?
Yes
What does saxitoxin do?
Blocks sodium channels.
Are hepatotoxins easily degraded? Are they water soluble or lipid soluble?
No, they are stable. Are water soluble.
What effect do cyanobacterial toxins have on the liver?
Intrahepatic haemorrhage, hepatomegaly, and necrosis
Name 4 ways cyanobacteria can be controlled.
Reduction in eutrophication
Reducing runoff with P and N
Mechanical disturbance
Increasing turbulence to bursts gas vacuoles and sink cells
Give an example for chemical control and biological control of cyanobacteria.
Chemical - mainly copper sulphate
Biological control - flagellates, amoeba, daphnids
What are toxic dinoflagellate blooms called?
Red tides
What storage molecules do dinoflagellates use?
Starch.
What pigments do dinoflagellates use (3)?
Chlorophyll a and c, carotenoids.
What reinforces dinoflagellates?
Plates of cellulose.
How many flagella do dinoflagellates have?
2 in perpendicular grooves.
Are dinoflagellates unicellular or colonial?
Mostly unicellular, but some colonial.
What are dinoflagellates called in their benthic resting stage? Name both.
Hypnocysts
Pellicle cysts
What are the walls like in hypnocysts? What about pellicle cysts?
Hypnocyst - thick walled
Pellicle - thin walled
What is the reproduction like in hypnocysts? What about pellicle cysts?
Hypnocyst - sexual
Pellicle - asexual
What is the longevity like in hypnocysts? What about pellicle cysts?
Hypnocyst - long lived
Pellicle - short lived
Are cyanobacteria prokaryotic or eukaryotic?
Eukaryotic
What kind of relationship do dinoflagellates have with coral reefs?
Symbiotic.
What is needed to germinate hypnocysts, and what can this lead to?
High temperatures needed, leading to a red tide.
What can surface upwelling result in with dinoflagellates?
May lead to red tides.
Aside from temperature and nutrition, what 3 factors can lead to a red tide?
Decreased salinity.
Increased vitamin b12
Increased humic substance
What are the respiratory symptoms of dinoflagellate toxins (4)?
Tract burning, sneezing, coughing, and allergy-like symptoms
What are 2 chronic symptoms of dinoflagellate toxicity?
Affects many organelles, including in mitochondria
Can cause cardiovascular arrest by interfering with sodium channels
What is the main toxin of dinoflagellates?
Saxitoxin.
Name 3 ways dinoflagellates can be detected.
Immunoassay ELISA
HPLC
Mouse bioassay
Name 2 ways cyanobacteria can be detected.
Mouse bioassay
Immunoassay ELISA
