Ch. 28: Protists Flashcards
1
Q
4 or 5 Supergroups
A
1) Excavata
2) Chromalveolata
3) Rhizaria
4) Archaeplastida
5) Unikonta
or 2 and 3 are combined into the “SAR” clade
2
Q
Excavata
A
“excavated” groove present on cell body of some
3
Q
“SAR” clade
A
- made up of:
Stramenopila
Alveolate
Rhizaria
4
Q
Stramenopila
A
- Part of the “SAR” clade
- Photosynthetic forms including Diatoms
- Possess flagellum with numerous fine, hairlike projections
- 4 types (Oomycota, Diatoms, Golden Algae, Brown Algae)
5
Q
Alveolates
A
- Part of the “SAR” clade
- Membrane-enclosed sacs just under membrane
6
Q
Rhizaria
A
- Part of the “SAR” clade
- Mostly amoebae with threadlike pseudopodia (thinner hairs)
7
Q
Archaeplastida
A
Red algae, Green algae, and land plants
8
Q
Unikonta
A
- Amoebae with lobe-like pseudopodia, fungi, animals
- Came about because two genes (dihydrofolate reductase (DFTR) and thymidylate synthase (TH) were two separate genes
9
Q
2-headed enzyme due to gene fusion
What are the two genes that fused and the result
A
- dihydrofolate reductase (DFTR) and thymidylate synthase (TH) fused to create DFTR-TS gene fusion
- gave rise to the Supergroups Excavata, Chromalveolata, Rhizaria, Archaeplastida
10
Q
Endosymbiosis
A
- Theory that refers to the ingestion of one cell by another cell that leads to symbiosis
- Explains origin of mitochondria plastids (chloroplasts, etc.)
11
Q
Primary Endosymbiosis
A
- Predatory protest eats bacteria
- i.e. plastid-bearing eukaryotes suggest that plastids evolved from a gram-negative cyanobacterium that was engulfed by an ancestral heterotrophic eukaryote
12
Q
Secondary Endosymbiosis
A
- How you get chloroplasts
- Predatory protist eats another predatory protist
- predatory protist eats another predatory protist that contains a chloroplast w/ nucleus => photosynthetic protist engulfed => nucleus form photosynthetic protist is lost (organelle with four membranes will lose one to have three membranes)
- i.e. that ancestral heterotrophic eukaryote then diversified into red algae and green algae, some of which were subsequently engulfed by other eukaryotes
13
Q
Chloroplasts
A
- Same idea as mitochondria
- A eukaryotic will eat photosynthetic bacteria
- Triple membrane
- Circular DNA
- Ribosomes
14
Q
Eukaryotic cells divide by
A
Mitosis
15
Q
Mitochondria divide by
A
Binary Fission
16
Q
Red Algae through Endosymbiosis
A
- Can give rise to three types of organisms: Dinoflagellates, Apicomplexans, Stramenopiles
17
Q
Green Algae through Endosymbiosis
A
- Can give rise to two types of organisms: Euglenoids and Chlorarachniophytes
18
Q
Giardia intestinalis
A
“hikers diarrhea”
- contaminated (fecal) stream or river water
- Supergroup Excavata => Diplomonads
19
Q
Trichomonas vaginalis
A
- Supergroup Excavata => Clade Parabasalids
- an STD
20
Q
Kinetoplastida
A
- Supergroup Excavata => Clade Euglenozoa
- large single mitochondrion possessing mass of DNA called a kinetoplast
i.e. Trypanosome gambiense: causative agent of African Sleeping Sickness
21
Q
Trypanosome gambiense
A
- Causative agent of African Sleeping Sickness
- Supergroup Excavata => Clade Euglenozoa => Kinetoplastida
22
Q
Euglenozoa
A
- Supergroup Excavata
- Euglenids: possess 2 flagellated from end-pocket, pellicle, paramylon granule
- Most autotrophic, but may switch to heterotrophy if sunlight is unavailable
23
Q
4 Groups within Stramenopila
A
1) Oomycota
2) Diatoms
3) Golden Algae
4) Brown Algae
24
Q
Oomycota
A
- Supergroup Chromalveolata (“SAR” clade)
- Water molds
- Cell walls made up of cellulose
- Hyphae
25
Diatoms
- Supergroup Chromalveolata ("SAR" clade)
- Unicellular algae
- Silica wall
- Major component of phytoplankton
26
Golden Algae
- Supergroup Chromalveolata ("SAR" clade)
- Photosynthetic
- Bi-flagellated
- Yellow carotenoids
27
Brown Algae
- Supergroup Chromalveolata ("SAR" clade)
- Largest forms in supergroup
- Seaweed/Kelp forests
- Thallus with holdfast, stipe, blades
28
Alveolates
- Supergroup Chromalveolata ("SAR" clade)
- Presence of membrane-bound sacs: function unclear
- Made up of Dinoflagellata
- Hazardous Algal Blooms (HAB)
- "Red Tides" - Karenia brevis
29
Dinoflagellata
- Supergroup Chromalveolata ("SAR" clade) => Clade Aveolates
- Flagellated forms
- Autotrophic and heterotrophic
30
Karenia brevis
- Supergroup Chromalveolata ("SAR" clade) => Clade Aveolates => Dinoflagellata
- Causes "Red Tides" => Saxitoxin (Na+ channel blocker, neurotoxin/paralytic)
31
Apicomplexa
- Supergroup Chromalveolata ("SAR" clade) => Clade Aveolates
- Presence of apical complex of organelles for penetrating host tissues
- i.e. Plasmodium
- i.e. P. falciparum, ovale, malariae, vivax
32
Plasmodium
- Supergroup Chromalveolata ("SAR" clade) => Clade Aveolates => Apicomplexa
- Causative agent of malaria
a top 5 goal disease affecting approximately 300 million die annually, most under the age 5 in sub-Saharan Africa
33
Plasmodium Life Cycle
2 hosts
1) Definitive host :mosquito => where sexually reproduces
2) Intermediate host: Vertebrate, such as a human, asexually reproduce
34
Ciliates
- Supergroup Chromalveolata ("SAR" clade) => Clade Aveolates
- Locomotion via cilia
- Macronuclei and Micronuclei
- Bladder-like contractile
- Food vacuoles
- Cytostome, cytoproct
-i.e. Paramecium, Stentor, Vorticella
35
3 types of Rhizaria
- Cercozoa
- Foraminifera
- Radiolarians
36
Cercozoa
- Supergroup Rhizaria ("SAR" clade)
- Amoeba-like
- Possess pseudopodia and some with cilia
- Mostly heterotrophic
37
Foraminifera
- Supergroup Rhizaria ("SAR" clade)
- Calcium carbonate (CaCO3) multi chambered shell with pores
- Found in freshwater and oceans
- Often attach to rock or algae
- Many photosynthetic via symbiotic alga
-i.e. fossilize well, Dover Cliffs in England
38
Radiolarians
- Supergroup Rhizaria ("SAR" clade)
- similar to the cercozoa, but
- Fused tests made of Silica
- Heterotrophic
- Axopodia with microtubes
39
Archaeplastida
- Red Algae
- Green Algae
- land plants
40
Red Algae
- Supergroup Archaeplastida
- Abundant in warm tropical waters
- Contain Phycoerythrin, an accessory pigment
- Grow as multicellular kelps
41
Green Algae (2 types)
1) Chlorophyta
| 2) Charophyta
42
Chlorophyta
- Supergroup Archaeplastida => Green Algae
- Similar to green plants
- Contain same Chlorophylls (a & b)
- Can be unicellular, colonial, or multicellular
i. e.
- Unicellular (Chlamydomonas)
- Colonial (Volvox)
- Multicellular (Ulva)
43
Charophyta
- Supergroup Archaeplastida => Green Algae
| - Branch includes Land Plants
44
Unikonta
- Made up of Amoebozoa
- Several different types of Amoebozoa
- Fungi
- Animals
- Choanoflagellates
45
4 types of Amoebozoa
1) Plasmodial Slime Molds (Myxogastridians)
2) Cellular Slime Molds
3) Tubulinids
4) Entamoeba
46
Plasmodial Slime Molds (Myxogastridians)
- Supergroup Unikonta => Amoebozoa
- Feeding stage is syncytial "slug"
- Consumes microorganism
- Reproductive structure a stalked sporangium
-i.e. Physarum polycephalum
47
Cellular Slime Molds
- Supergroup Unikonta => Amoebozoa
- Feed as solitary cells
- Aggregate to form fruiting bodies for reproduction
- Do not form syncytium at any time
-i.e. Dictyostellium sp.
48
Tubulinids
- Supergroup Unikonta => Amoebozoa
- Unicellular
- Soil, freshwater, marine
- Free-living
49
Entamoeba
- Supergroup Unikonta => Amoebozoa
- Parasitic
- Can form cysts (dominant form)
- cysts: soil/water, can accumulate
- trophozoite: intestine, feeding
- Cause of amoebic dysentery
-i.e. Entamoeba histolytica
50
Opisthokonts
- Supergroup Unikonta
| - Radiated into choanoflagellates, fungi, and animals
51
Most eukaryotes are
single-celled organisms
52
Mitochondria and chloroplasts are the result of
(primary and secondary) endosymbiosis
53
Closest relative to land plants
Red and Green algae
54
Closest related to fungi and animals
Unikonts (including protists)
55
What organisms play key roles in ecological communities?
Protists
