Protista 1 Flashcards
Entamoebae (a)
- Anaerobic human parasite.
- Entamoeba histolytica causes amoebic dyssentery. (small details in lecture 8)
- Non-pathogenic amoebae (Sarcodina) also exist within the Protista.
Entamoebae (b)
- Phagocytotic heterotrophs in water and soil.
- Also use CYST formation during unfavourable environmental conditions
Ciliates- Paramecium (a)
- Phylum Ciliophora
- Relatively complex eukaryotic microbes
- Cilia for motility
- Phagocytotic
- Some discharge barbed trichocysts for capturing prey and defence (also toxicycsts that release poison)
Ciliates- Paramecium (b)
- Usually have 2 nuclei
- One for reproduction (single copy of genome)
- One for metabolism ( multiple copies of genome) - Cilia create a spiral motion
- Paramecium food ingestion and excretion
- Paramecium also has a contractile vacuole for osmotic balance
- It is hypotonic to its fresh water surroundings
Ciliates- Plasmodium
- Phylum Apicomplexa
- Malaria and toxoplasmosis parasites are in this phylum
- Toxoplasmosis is a cat-human transmission that affects 7-70% of people depending on the area
-Plasmodium vivax is the cause of malaria (small details in L8)
The eukaryotic cell is
- Larger than a prokaryotic cell
- Has membrane-bound organelles
- Greater internal complexity
- specialized method of cell division that involves meiosis (genetic recombination)
Protista
eukaryotic, unicellular and multicellular
They are ‘polyphyletic’
The fungi are descended from fungi-like single celled heterotrophic eukaryotes called……
Chytrids
Animals are descended from single celled heterotrophic eukaryotes called…..
Choanoflagellates
The plants are descended from single celled photosynthetic eukaryotes called…….
chlorophytes
Diplomonads
- The diplomonads are obigate human pathogens
- lack mitochondria
- Giardia causes giardiasis, a common infection from poor restaurant hygiene ( i.e: Giardia Lamblia)
Microsporidia
- They are mainly animal parasites
- Lack mitochondria and flagella
- They have chitin cell walls like fungi
- Sequencing of other genes now places them within the fungi
- They are now regarded as highly reduced fungi
Trichomonads (a)
These are anaerobic, mitochondria and flagella posessing microbes that occur as animal endoparasites or endosymbionts
Trichomonads (b)
- Trichomonas vaginalis causes trichomoniasis
- This is the most common eukaryotic pathogen in developed countries
Trypanosomes - Phylum Euglenozoa
- Single flagellum
- but change morphology according to the host - All are obligate parasites
- important in human health, cause sleeping sickness (trypanosomiasis)
- Some species have secondary animal or plant hosts.
E.g: Trypanosoma cruzi
