Protists Info Flashcards
1
Q
Protists and humans
A
- Irish potato famine of 1845
- Malaria
2
Q
Algal Blooms
A
- Red tide
- Dinoflagellates
- Poisoning in humans
3
Q
Aquatic food chains
A
-Protists fix half of world’s carbon
4
Q
Protists and climate change
A
- Global carbon cycle
- Phytoplankton act as key carbon sink
5
Q
Diversification of Protista
A
- Paraphyletic
- Earliest eukaryotes must have had unicelluar, nucleus, mitochondria, no cell wall
6
Q
Protista
A
- Includes all eukaryotes (not land plants, fungi, and animals)
- no single trait found in Protista but not in other groups
- low species diversity
- extremely abundant
- not monophyletic
7
Q
Origin of the nuclear envelope
A
- Leading hypothesis: cell membrane folded in on itself; also creating ER
- Evidence: infoldings are present in some bacteria; nuclear envelopes is continuous with ER
- Advantage: separation of transcription of and translation
8
Q
Origin of mitochondria
A
- Endosymbiosis theory: mitochondrion took up residence in eukaryotic cell; 2 billion years ago; eukaryote engulfs bacteria but did not consume; eukaryote provided protection; bacterium supplied ATP
- Symbiosis: mutually beneficial for 2 species when in contact
- Endosymbiosis: symbiosis when 1 lives inside another
- Evidence: same size as bacterium; have own genes (self-replicate); manufacture own proteins; have double membranes
9
Q
Origin of the chloroplast
A
-photosynthesis originated in bacteria; protist engulfed cyanobactera; another protist engulfed that protist (secondary endosymbiosis); chloroplasts: have 4 membranes
10
Q
How do protists eat?
A
- Phagocytosis: ingest packets of food; eat bacteria, archaea, and other protists
- Absorptive feeding: nutrient taken directly from environment; common; decomposers; parasites
11
Q
Protist motion
A
- Amoeboid motion via pseudopodia
- Swimming via flagella
- Swimming via cilia
12
Q
Amoebozoa
A
- Phagocytosis
- Amoeboid motion: lobose pseudopods (blunt)
- includes amoebae and slime molds
13
Q
Rhizaria
A
- Amoeba-like
- Lack cell walls
- Amoeboid motion: long, slender pseudopodia
14
Q
Excavata
A
- “excavated” feeding groove
- lacks mitochondria
- e.g. Giardia
- Have flagella
15
Q
Excavata: Euglenida
A
- 1/3 are photosynthetic
- some have light sensitive eyespots: swim towards light