lecture 20 Flashcards
1
Q
Eukaryotic cells
A
- Morphologically larger than prokaryotic cells
- nucleus
2
Q
Eukarya divisions
A
- Protista
- fungi
- plantae
-Animalia
3
Q
How did eutraryotic cell arise?
A
- The environment changed from anaerobic to aerobic
- major events that occurred in the evolution of eukaryote cells are still conjectural
4
Q
Major events for arise of eukaryotic cells
A
- Origin of a flexible cell surface
- origin of a cytoskeleton
- origin of a nuclear envelope
- appearance of digestive resides or vacuous
- endosymbiotic acquisition of some organelles
5
Q
Flexible cell surface (eutaryotic cells arise)
A
- Prokaryotic cell wall was lost
- can grow larger
6
Q
What happens when a cell’s size increase?
A
- Surface-area-to-volume ratio decreases
- with flexible cell surface, infolding can occur
- creates more surface area
- leads to endomembrane system
7
Q
The endosymbiosis theory
A
- Cyanobacteria produced oxygen
- at some point, early eukaryotes engulfed bacteria that evolved into mitochondria
- some eukaryotes incorporated a prokaryote related to today’s Cyanobacteria, that developed into chloroplasts
8
Q
Initial function of mitochondria in early eukaryotes
A
- Detoxify oxygen or by reducing it to water
- now, ATP production
9
Q
what did some eukaryote do (with prokaryote)?
A
Incorporated a prokaryote related to today’s canobacteria, which developed into chloroplasts
10
Q
protists
A
- eukaryotes (so, have organelles and are more complex than prokaryotes)
- most are unicellular
- some colonial and multicellular species
11
Q
characteristics of protists
A
- evolved diverse cell structures, ecological roles and life histoires
- vary in size, structure, mode of locomotion, and reproduction
- most are motile
- reproduction ranges from asexual to sexual modes
- most are aquatic (terrestrial protists are found in moist environmements)
- autotrophic or heterotrophic
- unicellular to multicellular
12
Q
microbial eukaryotes
A
- have great diversity
- most microscopic, but some are large (ex.; giant kelp)
- many have plankton
13
Q
plankton
A
free floating, microscopic, aquatic organisms
14
Q
phytoplankton
A
plankton that are photosynthetic
15
Q
protist group
A
taxonomic trash can
