week 6 - protists --> Alveolates

Question 1

Alveolates

Answer 1

• Characterised by alveoli under cytoplasmic membrane
  o Air sacs (define the morphology)
   Function unknown: osmoregulation, secretion?
  —-> if outer membrane peeled back can see the pits of the air sac
  o Many have a double membrane

Question 2

Alveolates
three important groups

Answer 2

• Ciliates
• Dinoflagellates
• apicomlexans

Question 3

Alveolates:
ciliates

Answer 3

• All have cilia.
  o Used for motility and feeding.
   Motile because of cilia
   Cilia move in unison.
   Also, cilia is for feeding
   Specialised area not covered in cilia for ingestion.
   Cilia direction food towards this area
• Macro and micro nuclei
  o Micro = genes for sexual reproduction
  o Their reproduction is unusual and complicated.
   Involves a temporary fusing of two cells and they swap their micronuclei.
• Some are anaerobic fermenters in the gut
• Some parasites/some symbionts
  o Symbionts do good for the ecosystem.

Question 4

Alveolates
ciliates example

Answer 4

Example: Paramecium
Have two membranes
The pellicle
* Can see alveoli sacs on diagram

Question 5

Alveolates:
dinoflagellates

Answer 5

• Two flagella
  o Different sizes and positions
• Phototrophic (sec. endosym.)
• Aquatic and can be:
  o Toxic (“red tides”) -> kill fish because of the accumulation of neurotoxins
  o Bioluminescent
  o Free-living/symbionts (coral reefs)

Question 6

Alveolates:
Apicomplexans

Answer 6

• All are obligate animal parasites
  o Need a host to survive
• Have degenerate chloroplasts called APICOPLASTS, thought to originate form a red alga
  o Define morphology (fatty acid synthesis? They do not photosynthesise)
• Include major human pathogens Plasmodium and Toxoplasma