GEOLOGY 105 EXAM 2 COFC
Burgess Shale - Answers :- descent with modification
- all basic body parts existed
- every animal for last 500 million years comes from changes in these body plans
- complex community
Red Queen Hypothesis - Answers :"it takes all the running you can do, to keep in the
same place"
- a species must adapt and evolve for survival and reproduction
Tiktaalik - Answers :- 375 mya
- had the first neck and wrist
- eyes on top of skull
- extinct
Ichthyostega - Answers :- amphibian
- fish-like tail
- 7 toes- reduction of toes
Eukaryotes - Answers :have cells with:
- a membrane bound organelles
- a nucleus
- large in size
- requires oxygen
prokaryotes - Answers :have cells with:
- a coil of DNA
- no membrane bound organelles
- do not require oxygen
- no nucleus
- small in size
Endosymbiosis - Answers :endo: inside, symbiosis: relationship for mutual benefit.. ex:
bacteria becomes mitochondrion
Snowball Earth - Answers :- reduces CO2 fluxes in the atmosphere
- the world completely ices over
- weathering shuts down
- ocean becomes anoxic (no oxygen)
Ediacaran - Answers :- 635-542 mya
- final stage of snowball earth
- had 1st macroscopic animals
- 1st possibly surface locomotion (interfering muscle evolution)
- increase in sedimentation oxygenation
, - decline of microbial mats, possible grazing
4 groups of fossils:
- segmented animals
- fronds
- jellyfish impressions
- tracks
Mistaken point - Answers :- Newfoundland, Canada
- Volcanic ash dated 565 mya
- oldest complex Ediacaran fossils accurately dated
- they have been assigned to a completely different kingdom of multi-cellular organisms
- marine environment
Cambrian explosion possible causes - Answers :1. increased geologic activity- more
volcanic eruptions, increases CO2 in atmosphere, warmer temp, sea level rise
2. Increased food supply- increases in ocean productivity
3. Oxygen level increases- photosynthesis
4. How genes (homeobox genes)- small gene changes, large structural change
5. Evolution of the eyes- important for predators
6. Complex community development- predator/prey interactions
Pikaia - Answers :Found in Burgess shale, they were the earliest vertebrates/fish.
survived extinction, oldest chordate
Chordates - Answers :Has a
- notochord (rod-like structure)
- gills (gas exchange) internal
- single dorsal nerve cord (on top) brain
- tail
Ostracoderm - Answers :- Earliest jawless fish ("plated skin")
- lack an internal bony skeleton
- plates on skin provided protection
osteostracans - Answers :- first paired fins
- jawless
- flexible body and tail
- head shield
placoderm - Answers :- first jawed vertebrae
- Early Silurian period (430 mya extinction in Carboniferous 360 mya)
- very diverse in Devonian
- much of body covered with bony plates
- true teeth absent
Ray finned fish - Answers :- multiple paired fins
Burgess Shale - Answers :- descent with modification
- all basic body parts existed
- every animal for last 500 million years comes from changes in these body plans
- complex community
Red Queen Hypothesis - Answers :"it takes all the running you can do, to keep in the
same place"
- a species must adapt and evolve for survival and reproduction
Tiktaalik - Answers :- 375 mya
- had the first neck and wrist
- eyes on top of skull
- extinct
Ichthyostega - Answers :- amphibian
- fish-like tail
- 7 toes- reduction of toes
Eukaryotes - Answers :have cells with:
- a membrane bound organelles
- a nucleus
- large in size
- requires oxygen
prokaryotes - Answers :have cells with:
- a coil of DNA
- no membrane bound organelles
- do not require oxygen
- no nucleus
- small in size
Endosymbiosis - Answers :endo: inside, symbiosis: relationship for mutual benefit.. ex:
bacteria becomes mitochondrion
Snowball Earth - Answers :- reduces CO2 fluxes in the atmosphere
- the world completely ices over
- weathering shuts down
- ocean becomes anoxic (no oxygen)
Ediacaran - Answers :- 635-542 mya
- final stage of snowball earth
- had 1st macroscopic animals
- 1st possibly surface locomotion (interfering muscle evolution)
- increase in sedimentation oxygenation
, - decline of microbial mats, possible grazing
4 groups of fossils:
- segmented animals
- fronds
- jellyfish impressions
- tracks
Mistaken point - Answers :- Newfoundland, Canada
- Volcanic ash dated 565 mya
- oldest complex Ediacaran fossils accurately dated
- they have been assigned to a completely different kingdom of multi-cellular organisms
- marine environment
Cambrian explosion possible causes - Answers :1. increased geologic activity- more
volcanic eruptions, increases CO2 in atmosphere, warmer temp, sea level rise
2. Increased food supply- increases in ocean productivity
3. Oxygen level increases- photosynthesis
4. How genes (homeobox genes)- small gene changes, large structural change
5. Evolution of the eyes- important for predators
6. Complex community development- predator/prey interactions
Pikaia - Answers :Found in Burgess shale, they were the earliest vertebrates/fish.
survived extinction, oldest chordate
Chordates - Answers :Has a
- notochord (rod-like structure)
- gills (gas exchange) internal
- single dorsal nerve cord (on top) brain
- tail
Ostracoderm - Answers :- Earliest jawless fish ("plated skin")
- lack an internal bony skeleton
- plates on skin provided protection
osteostracans - Answers :- first paired fins
- jawless
- flexible body and tail
- head shield
placoderm - Answers :- first jawed vertebrae
- Early Silurian period (430 mya extinction in Carboniferous 360 mya)
- very diverse in Devonian
- much of body covered with bony plates
- true teeth absent
Ray finned fish - Answers :- multiple paired fins
