Taxonomy of eukaryotes Flashcards
(45 cards)
What is the sequencing of gene used in phylogeny of eukarya?
18S rRNA
But Phylogeny constructed to also take in account other genes–> new insights because of this
What are cysts?
Similar to endospores produced by prokaryotes. Used to protect the cell against deleterious environmental conditions (to survive long periods of starvation/desication and also infection of prokaryotes)
What are 2 orgnelles found in amitochondriate eukaryotes, and what are they involved in?
Mitosomes –> involved in maturation of iron sulfur closters
Hydrogenosomes–> Participate in oxidation of pyruvate to H2, CO2 and acetate.
What is a Hydrogenosome?
Present in amitochondriates. Present in eukaryotes with STRICTLY FERMENTATIVE METABOLISM. Sometimes endosymbiotic bacteria are present (…)
What is a Mitosome?
Present in amitochondriates. Derived from mitochondrion. HAS NO ENZYMES FOR TCA CYCLE/ NO RESP. CHAIN.
What are common characteristics of Diplomads and Parabasalids?
- Unicellular
- Flagellated
- No chloroplasts
- Live in ANOXIC habitats
Name 2 characteristics of diplomads
- Unicellular
- Flagellated
- No chloroplasts
- Live in ANOXIC habitats
- 2 NUCLEI
- MITOSOMES
- Key genera: GIARDA (causes giardasis)
Name 3 characteristics of parabasalids
- Have parabasal bodies (structure to support golgi complex)
- AMITOCHONDRIATE
- HYDROGENOSOMES for ANAEROBIC metabolism
- Live in intestinal or urogenital tracts of animas as parasites or symbionts
- Key genera: Trichomonas vaginalis (STD in humans, doesn’t form cysts , doesn’t survive outside the host)
2 common characteristics of euglenozoans?
UNICELLULAR and FLAGELLATED
What are the subgroups of euglenozoans?
Kinetoplastids and Euglenids
Characteristics of kinetoplasts?
- Mass of DNA present in their SINGLE, LARGE MITOCHONDRION
- Live in AQUATIC environment.
- Feeding on bacteria
- Some species cause serious disease in humans
- TRYPANOSOMA BRUCEI : african sleeping sickness= chronic, fatal infection.
Characteristics of Euglenids?
- EUGLENA = specie
- NON PATHOGENIC
- PHOTOTROPHIC
- CONTAINS CHLOROPLASTS
- can exist as HETEROTROPH (will loose chloroplast if incubate in dark for long time)
- feed on bacteria by PHAGOCYTOSIS
Common characteristics of alveolates?
- Presence of ALVEOLI ( sac underneath cytoplasmic membrane)
- Alveoli may fct to help cells maintain osmotic balance
Subgroups of alveolate family?
Ciliates
Dynoflagellates
Apicomplexans
Characteristics of ciliates?
- Have cilia (for food and motility)
- Most wildey dstributed genera: PARAMELIUM
- Have 2 NUCLEI (macro and micro)
- During SEXUAL REPROD: exchange of MICRONUCLEI
- Some ciliates= animal parasites or symbionts (in rumens)
Characteristics of dynoflagellates?
- Marine, freshwater
- PHOTOTROPHIC
- Have 2 FLAGELLAS (transversal or longitudinal)
- May be TOXIC ( produce neurotoxins, warm and polluted water= dyno. can reach high amount, can cause human poisening = paralitic shellfish poisening)
Characteristics of apicomplexans?
- OBLIGATE PARASITES of animals
- COMPLEX LIFECYCLE : Sporozoïte, Gametocyte, other…
- Has APICOPLASTS ( degenerate chloroplasts that lack pigment and phototrophic capacity)
- Cause severe diseases: M
Common characteristics of strametopiles?
- All FLAGELLATES
- Are chemoheteroptrophs or phototrophes
Subgroups of Stramenopiles?
Oomycetes
Golden Algea
Diatoms
Characteristics of Oomycetes?
- CHEMOHETEROTROPHS
- Water molds
- Cell wall made of CELLULOSE
- PHYTOPHTORA INFESTANS = late bright disease in potatoes–> irish potato famine
Characteristics of Diatoms?
- UNICELLULAR
- PHOTOTROPHIC
- Freshwater or marine
- FRUSTULES: cell walls made of silica with prots and polysaccharides–> protects against predation
Characteristics of Golden Algae?
- PHOTOTROPHIC
- Also called chrysophytes
- Mostly UNICELLULAR , some COLONIAL
- CHLOROPLAST pigment dominated by CAROTENOID FUCOXANTHIN
Common characteristic of Cercozoans and Radiolans?
Threadlike pseudopodia
Exemple of Cercozoan?
Foraminifera
