Chapter 29 Flashcards
What is geological time first divided into?
eons
What are eons divided into?
eras
What are eras divided into?
periods
How many eons have there been?
Four eons
From the oldest to the current, what are the four eons?
- Hadean
- Archean
3.Proterozoic - Phanerozoic
What eons are considered Precambrian?
Hadean, Archean, Proterozoic
What eons are considered Cambrian?
Phanerozoic
What is a basic descriptive phrase of the Hadean eon?
no rocks
What is a basic descriptive phrase of the Archean eon?
fossils of prokaryotes
What is a basic descriptive phrase of the Proterozoic eon?
oldest definite fossils of eukaryotes
What is a basic descriptive phrase of the Phanerozoic eon?
greatest diversity
The early atmosphere likely had levels of ______
CO2
What causes CO2 to increase?
Volcanic erruptions
What causes CO2 to decrease?
Weathering
What is weathering?
The conversion of rock to soil
Which is greater the CO2 released in the atmosphere or the decrease of CO2 because of weathering?
The decrease of CO2
What builds geological features?
The tectonic plates shifting
What did Rodinia contain?
All the continents
What did Gondwana contain
all southern hemisphere continents
Which eon does life supposedly come from?
Archean
Where did the origin of life emerge from?
early water
What did the evolution of cells require?
Early organic molecules to assemble to form functional independent units
What is the extraterrestrial theory with relation to the early molecules?
That meteorites and comets have carried organic material
What are the two proposed atmospheres for early earth to form the early molecules?
- CO2, H2O, N2
2.H2, S, N, C, H2S, NH3, CH4
What is the time frame for the Hadean eon?
About 4-4.5 BYA
What is the time frame for the Archean eon?
About 2.5- 4 BYA
What is the time frame for the Proterozoic eon?
2.5 BYA to 541 MYA
What is the time frame for the Phanerozoic eon?
541 MYA to now
What is a reducing atmosphere?
One where oxidizers are lacking (like O2) and reducing gases like H2 and CO are present.
What type of environment did the Mille and Urey experiment create?
a reduced atmosphere
What was the result of the Mille and Urey experiment?
carbon compounds were indentified
What were two important landmarks in the evolution of metabolism
- autotrophic origin
- Heterotrophic origin
What does it mean in relation to the evolution of metabolism that it has an autotrophic origin?
energy from the oxidiation of inorganic compounds due a reductive version of the critic acid cycle
What does it mean in relation to the evolution of metabolism that it has an heterotrophic origin?
The mille urey experiment (essentially) life just evolved from carbon materials
It is very likely that organisms emerged and lived at ____ temperatures
high
When was there fossil evidence?
3.2 BYA
What form of fossils are difficult to find?
microfossils
What rock layer is assumed to be the biological origin?
craton
______ resemble prokaryotes from 3.2 BYA
microfossils
What is an example of indirect evidence of fossils?
stromtolites
What are stromtolites?
sedimentary deposits
How are stromalites held in place?
by microorganism (cyanobacteria
What data indicates that carbon fixation is an ancient process?
Isotopic data
What does spectroscopic analysis show?
The presence of complex carbon molecules
What is carbon fixation?
The incorporation of inorganic carbon into organic form
What are two methods of carbon fixation?
- calvin cycle
- citric acid cycle
What are found in ancient rocks?
hydrocarbons
What serve as biomarkers?
organic compounds
What isotope ratio indicate biological origin?
carbon
What is climate?
temperature and water availability
_____ and ____ affect the ability of organisms to survive and reproduce
climate and atmosphere
The earth has been ____ since its formation
cooling
Decline of ____ in the Proterozoic eon ____ weathering and led to glaciations
CO2, slowed
Actual weather increases _____, which shifts tectonic plates, causing glaciation
weathering
____ motion affected evolution
continental
What are ways that shifting plates can impact species?
- can cause reproductive isolation
- can allow previously separated species to interbreed
What land mass formed at the end of the Paleozic era?
Pangea
When Pangea broke up what era and start of the period was it?
It broke up in the Mesozoic era and began the Jurassic period
What period did the Appalachia form?
Permian
What era did Australia and Antaratic separate?
Cenozoic era
What led to the evolution of cellular respiration?
oxygenic photosynthesis
Early plants released _________ that can increase rock weathering
organic acid
The diversification of vascular plants’ root systems increased _____
weathering
Do eukaryotes extensively compartmentalize?
Yes
What is the endomembrane system?
Allows the cell to divide into functional compartmentally, and the folding of the membrane
What is the endosymbiosis origin of eukaryotes?
Essentially the endocytosis of prokaryotes into the cell (mitochondria and chloroplast)
What does multicellularity allow?
specialization by allowing organisms to deal with their environment through the differentiation of cell types into tissue and organs
What did photosynthesis lead to the atmospheric development of?
The ozone layer
What does the ozone layer protect us from?
UV radiation
