Questions and Answers
Which of the following are included in the macro evolutionary changes shown by the fossil record? (Select all that apply)
Which of the following are stages in the production of very simple cells on early Earth? (Select all that apply)
When did Earth form?
4.6 billion years ago
What did Earth's early atmosphere likely contain?
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What did A.I. Oparin and J.B.S. Haldane hypothesize about the early atmosphere?
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What did the experiments by Stanley Miller and Harold Urey demonstrate?
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Where may the first organic compounds have been synthesized?
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What does the theory of panspermia suggest?
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What are the key properties of life?
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What are protobionts?
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What do protobionts exhibit?
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What does the fossil record reveal?
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What are sedimentary rocks?
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What do strata represent?
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What characteristics make species favored in the fossil record? (Select all that apply)
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What do sedimentary strata reveal?
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What is radiometric dating?
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What is a half-life?
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What can radiocarbon dating be used to date?
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What can the magnetism of rocks provide?
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What do reversals of the magnetic poles leave?
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What are tetrapods?
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How is the geological record divided?
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What does the Phanerozoic encompass?
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What are the three eras of the Phanerozoic?
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What do major boundaries between geological divisions correspond to?
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What are the oldest known fossils?
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How long were prokaryotes Earth's sole inhabitants?
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Which of the following statements about oxygen is true? (Select all that apply)
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What is the Oxygen Revolution?
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When did the oldest eukaryotic cells appear?
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What does the hypothesis of endosymbiosis propose?
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What is key evidence supporting an endosymbiotic origin of mitochondria and plastids? (Select all that apply)
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What occurred during the second wave of diversification?
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What does the 'snowball Earth' hypothesis suggest?
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What does the Cambrian Explosion refer to?
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When did fungi, plants, and animals begin to colonize land?
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When did plants and fungi likely colonize land together?
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What are arthropods and tetrapods?
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How many times have Earth's land masses formed a supercontinent?
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What happens to Earth's crust? (Select all that apply)
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What were the effects of the supercontinent Pangaea?
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What did the breakup of Pangaea lead to?
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Which statements about fossils are true? (Select all that apply)
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What does the Permian extinction define?
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What did the Cretaceous mass extinction result in?
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What does the presence of iridium in sedimentary rocks suggest?
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How much higher is the current rate of extinction compared to the typical background rate?
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What can mass extinction pave the way for?
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What is adaptive radiation?
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Study Notes
Fossil Record and Macro Evolution
- Fossil record indicates significant macroevolutionary changes, including terrestrial vertebrates' emergence, the origin of photosynthesis, and long-term mass extinction impacts.
- Sedimentary rocks, formed in strata, serve as the richest fossil source, revealing changes over time.
Early Earth and Life Formation
- Earth originated approximately 4.6 billion years ago, developing a primordial atmosphere rich in water vapor and volcanic chemicals like nitrogen and methane.
- A.I. Oparin and J.B.S. Haldane proposed that the early atmosphere lacked oxygen, creating a reducing environment conducive to life.
- Experiments by Stanley Miller and Harold Urey demonstrated that organic molecules could be synthesized abiotically in such an atmosphere.
Evolution of Organic Compounds
- Initial organic compounds may have originated near underwater volcanoes and deep-sea vents, rather than in the atmosphere.
- The Panspermia theory supports the idea that life could have extraterrestrial origins, evidenced by amino acids found in meteorites.
Characteristics and Evolution of Life
- Key properties of life include replication and metabolism, critical for the development of protobionts, which are aggregates of molecules enclosed in a membrane-like structure.
- Protobionts demonstrated simple reproduction and metabolism, maintaining an internal chemical environment.
Geological Timeline and Eons
- The geological record is divided into Achaean, Proterozoic, and Phanerozoic eons, with the Phanerozoic encompassing multicellular life.
- The Phanerozoic is further segmented into Paleozoic, Mesozoic, and Cenozoic eras, with significant extinction events marking boundaries.
Evolutionary Milestones
- The oldest fossils, stromatolites, indicate life existed 3.5 billion years ago, primarily consisting of prokaryotes until about 2.1 billion years ago.
- The Oxygen Revolution, beginning around 2.7 billion years ago, marked an increase in atmospheric oxygen due to cyanobacteria, enabling new energy sources and diverse ecosystems.
Eukaryotic Evolution
- The oldest eukaryotic cells date back to 2.1 billion years. The endosymbiotic hypothesis posits that mitochondria and plastids originated from prokaryotes living within host cells, supported by structural and functional similarities.
Cambrian Explosion and Land Colonization
- The Cambrian Explosion (535 to 525 million years ago) witnessed the rapid appearance of fossils resembling modern phyla.
- Fungi, plants, and animals began terrestrial colonization around 500 million years ago, likely in concert, with evidence of joint colonization by plants and fungi by 420 million years ago.
Continental Drift and Supercontinents
- Earth's continents shift gradually due to continental drift, influencing geological formations, climate, and ecosystems.
- Pangaea, the last supercontinent, formed about 250 million years ago, altering shallow water habitats and overall climate, and later fragmented, leading to allopatric speciation.
Mass Extinctions and Their Consequences
- The Permian extinction event (~252 million years ago) was catastrophic, killing approximately 96% of marine species.
- The Cretaceous mass extinction (65.5 million years ago) led to the demise of many species, including dinosaurs, likely due to a meteorite impact, with sedimentary evidence of iridium confirming this hypothesis.
- Current extinction rates are alarming, estimated to be 100 to 1000 times the background rate, indicating a potential mass extinction and subsequent adaptive radiations in the future.
Adaptive Radiation
- Adaptive radiation describes the evolution of diverse species from a common ancestor, particularly after environmental changes or the introduction of new niches.
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Description
Explore the fascinating history of life on Earth through these flashcards covering key concepts in AP Biology Chapter 25. From the emergence of terrestrial vertebrates to the origins of photosynthesis, test your knowledge on macroevolutionary changes and early cellular processes. Perfect for study and revision!