Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
AP Biology Chapter 25 Notes The History of Life on Earth What you need to know… • The ____________ of the Earth and when prokaryotic and eukaryotic life emerged. • Characteristics of the _____________ planet and its atmosphere. • How ___________ and _______________ tested the Oparin-Haldane hypothesis and what they learned. • Methods used to __________________ fossils and rocks. • Evidence for _____________________________. • How continental drift can explain the current ___________________ of species. Concept 25.1: Conditions on early Earth made the origin of life possible Chemical and physical processes on early Earth may have produced very simple cells through a sequence of 4 stages: 1. Small ________________________ molecules were synthesized 2. Joining of these small molecules into ___________________________ (proteins, carbs, etc) 3. Packaging of molecules into “________________________” (membrane-containing droplets, whose internal chemistry differed from that of the external environment) 4. Origin of ______________-replicating molecules A. I. Oparin and J. B. S. Haldane – hypothesized that the ____________ atmosphere, thick with water vapor, nitrogen, carbon dioxide, methane, ammonia, hydrogen, and hydrogen sulfide, with energy from lightening and UV radiation could have formed organic compounds Stanley Miller and Harold Urey conducted lab experiments to test this __________________________ and produced a variety of amino acids ________________________________ are aggregates of abiotically produced molecules surrounded by a membrane or membrane-like structure The first genetic material was probably self-replicating RNA, not DNA o RNA molecules called ________________ have been found to catalyze many different reactions o For example, ribozymes can make complementary copies of short stretches of their own sequence or other short pieces of _________________ Concept 25.2: The fossil record documents the history of life • The fossil record is biased in favor of species that – ___________________ for a long time – Were __________________________ and _____________________________ – Had ______________________ parts • The absolute ages of fossils can be determined by ______________________ dating • Each isotope has a known ________________________, the time required for half the parent isotope to decay Concept 25.3: Key events in life’s history include the origins of single-celled and multicelled organisms and the colonization of land • The _______________________ record is divided into the Archaean, the Proterozoic, and the Phanerozoic eons • The oldest known fossils are _________________________, rock-like structures composed of many layers of bacteria and sediment • • • • • • This “oxygen revolution” from 2.7 to 2.2 billion years ago – Posed a ______________________ for life – Provided opportunity to ___________________ energy from light – Allowed organisms to exploit ____________ ecosystems The hypothesis of ___________________________ proposes that mitochondria and plastids (chloroplasts and related organelles) were formerly small prokaryotes living within larger host cells – An __________________________ is a cell that lives within a host cell – Key evidence supporting an endosymbiotic origin of mitochondria and plastids: • Similarities in inner ________________________ structures and functions • ________________________ is similar in these organelles and some prokaryotes • These organelles __________________ and ______________________ their own DNA • Their ______________________ are more similar to prokaryotic than eukaryotic ribosomes ___________________________________________________ began to colonize land about 500 million years ago ______________________________________ likely colonized land together by 420 million years ago _______________________________________ are the most widespread and diverse land animals ___________________________ evolved from lobe-finned fishes around 365 million years ago Concept 25.4: The rise and fall of dominant groups reflect continental drift, mass extinctions, and adaptive radiations • • • • • • Earth’s continents move slowly over the underlying hot mantle through the process of ____________________________________________ – Oceanic and continental plates can collide, separate, or slide past each other – Interactions between plates cause the formation of mountains and islands, and earthquakes Formation of the supercontinent _____________________ about 250 million years ago had many effects – A _______________ in shallow water habitat – A _________________ and ______________ climate inland – Changes in ____________________ as continents moved toward and away from the poles – Changes in _______________ circulation patterns leading to global cooling The break-up of Pangaea lead to ______________________ speciation The current distribution of _______________ reflects the movement of continental drift At times, the rate of ____________________ has increased dramatically and caused a ___________________________________ (loss of large numbers of species in short periods of time) – By removing large numbers of species, ecological communities can be drastically altered losing evolutionary ______________________ forever Mass extinction can pave the way for _______________________________________ (periods of evolutionary change where groups of organisms form many new species whose adaptations allow them to fill different ecological niches) – EX. Galapagoas finch species Concept 25.5: Major changes in body form can result from changes in the sequences and regulation of developmental genes “_____________” – a filed of study in which evolutionary biology and developmental biology converge Illuminating how slight _____________ divergences can be magnified into major morphological differences between species Sometimes, structures that originally played one role gradually acquire a different one – ___________________ EX. Feathers of modern birds were co-opted for flight after functioning in some other capacity such as thermoregulation _______________________ is an evolutionary change in the rate or timing of developmental events The contrasting shapes of human and chimpanzee skulls are the result of small changes in relative growth rates In ______________________________, the rate of reproductive development accelerates compared with somatic development _________________________ genes determine such basic features as where wings and legs will develop on a bird or how a flower’s parts are arranged Ex. Hox Genes Hox genes are a class of homeotic genes that provide ____________________ information during development If Hox genes are expressed in the wrong location, body parts can be produced in the wrong location You should now be able to… 1. Define radiometric ____________________, serial ______________________, Pangaea, snowball Earth, __________________, _______________________, and _________________________ 2. Describe the contributions made by Oparin, Haldane, Miller, and Urey toward understanding the ________________ of organic molecules 3. Explain why RNA, not DNA, was likely the _____________________ genetic material 4. Describe and suggest evidence for the ____________________ events in the history of life on Earth from Earth’s origin to 2 billion years ago 5. Briefly describe the Cambrian explosion 6. Explain how continental drift _____________ to Australia’s unique flora and fauna 7. Describe the ___________________ extinctions that ended the Permian and Cretaceous periods 8. Explain the function of ______________ genes