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Bio II Exam 2: Eukarya and Protists

Terms in this set (50)

All eukarya are protists except for?
fungi, animals, and land plants
How do eukaryotic cells differ from prokaryotic cells?
1. Nuclear envelope defines eukarya
2. Cytoskeleton: system of structural proteins
3. complex and extensive organelles
What did the first eukaryotes have?
1. single-cell
2. nucleus and endomembrane system
3. Mitochondria
4. cytoskeleton
5. No cell wall
6. Novel flagellum
Where did this nulceaur envelope come from?
Derived from the infoldings of the plasma membrane
What does the endosymbiosis theory state?
mitochondria originated when a bacterial cell took up residence inside a eukaryote about two billion years ago; therefore eukaryotes arose from prokaryotes.
How does symbiosis occur?
When individuals of two different species live in physical contact
How does endosymbiosis occur?
When an organism of one species lives inside and organism of another species
What are the 3 proposed steps of evolution of the mitochondria?
1. The host cell- predator capable of one anaerobic fermentation
2. The process began when eukaryotic cells started to use their cytoskeletal elements to engulf aerobic bacteria, which then lived symbiotically with their host
3. The eukaryotic supplied the bacterium with protection and carbon compounds, which the bacterium oxidized. The the bacterium supplied the host with ATP.
What is the endosymbiosis theory?
1. Chloroplast originated when a protist engulfed a cyanobacterium
2. Once inside the protist, the photosynthetic bacterium provided its eukaryotic host with oxygen and glucose in exchange for excess protection and access to light
When does secondary endosymbiosis occur?
When an organism engulfs a photosynthetic eukaryotic cell and retains its chloroplasts as intracellular symbionts.
Cells lack cell walls. When portion of the cell extend outward to move the cell, they form large lobes.
Amoebozoa
Reproductive cells have a single flagellum at their base. The cristae inside mitochondria are flat and not tube shaped.
Opisthokonta
Most cells have a pronounced "feeding groove" where prey or organic debris is ingested. Most lack typical mitochondria.
Excavata
Cells have chloroplasts with a double membrane
Plantae
Lack cell walls, although some produce a shell-like covering. When portions extend outward they are slender in shape.
Rhizaria
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