Exam III Flashcards
What are spontaneous generation and panspermia?
spontaneous generation: belief that life spontaneously arose from rotting meat
panspermia: life seeded by chemical compounds or spores from meteorites
What are the necessary traits, composition, conditions, and components for life?
traits: open systems, cell membranes, reproduce, complex dna info storers, changes and mutations
composition: carbon, hydrogen, nitrogen, sulfur, and phosphorous
conditions: deep ocean hydrothermal events
components: proteins, nucleic acids, organic phosphorous compounds, a container lol (#tupperwareformyskinsack)
What did the Urey-Miller experiments reveal about the origin of life?
amino acids need UV radiation or lightning or charged surfaces to zap acids together into chains
Why are hydrothermal vents thought to be where life began?
warm, deep, anaerobic (no oxygen)
What is a prokaryote?
simple single that’s a proud asexual
Why are earliest fossils (prokaryote fossils) rarely found?
soft bodied, microscopic
What are stromatolites?
mat like colonies of photosynthetic cyanobacteria
How do eukaryotes differ from prokaryotes?
eukaryotes are complex single cells that sexually reproduce, have organelles and variable evolution
What were the Ediacarans?
large metazoan organisms (multicellular, eukaryotic) that came after snow ball earth (end of proterozoic eon), related to increase in oxygen and warm marine areas
similar to jellyfish, corals, and worms
What is the importance of small shelly fauna?
the shells evolved to protect soft tissue, increasing probability of preservation
Know the 5 steps to complex life.
- prokaryotic bacteria
- eukaryotic cells
- multicellular soft bodied organisms
- tiny, shelled organisms
- large shelly animals
When did the Paleozoic Era begin?
542 Ma
What is the order of Paleozoic periods?
Cambrian, Ordovician, Silurian, Devonian, Carboniferous (Miss, Penn), Permian
What are cratonic sequences and how do they form?
definition: deposition sequences bounded by unconformities
how they form: transgressions and regressions of epicontinental seas
top: erosion
regressive sediments
maximum sea level
bottom: transgressive sediments
What are epicontinental seas?
Shallow seas that flood broad, low-lying areas of continents
Why are quartz sandstones important resources?
used to make glass
used for hydraulic fracturing by propping opening fractures
What was the location and climate of Laurentia?
equatorial, tropical
What is a clastic wedge and how does one form?
an expansive wedge shaped deposit of gravels, sands, and muds eroded and extending from the mountain front
form during orogeny bc of continental collision
Know about the Cambrian Explosion represented by Burgess Shale. How were the fossils preserved?
as mostly soft parts
60,000 specimens collected
What formed reefs in the early Paleozoic?
stromatolites and archaeocyathids “ancient cups”
What are the other dominant organisms of the early Paleozoic?
trilobites: euryptids
brachiopods
graptolites: planktonic bois
Why did so much salt accumulate in the Michigan Basin?
it was a hot shallow lagoon basin with a narrow neck restricting ocean flow
Why do black shales form?
bc high organic content gets buried with low oxygen in warm, high water