Chapter 25: History of Life on Earth Flashcards

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1
Q

Membrane encloses molecules, maintains its own environment.

Packaging of molecules before cells were created

A

Protocells

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2
Q

chemical and physical processes on early earth may have produced very simple cells through what stages?

A
  1. Abiotic synthesis of small organic molecules
  2. Joining of these small molecules into macromolecules
  3. Packaging of molecules into pro cells
  4. Origin of self replicating molecules
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3
Q

What formed about 4.6 billion years ago?

A

The earth along with the rest of the solar system

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4
Q

Who performed lab experiments that showed that the abiotic synthesis of organic molecules in a reducing atmosphere is possible?

A

Stanley Miller and Harold Miller in 1953

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5
Q

What are the key properties of life that Protocells have?

A
  • maintain their own environment

- capable of splitting

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6
Q

What was probably the first genetic material?

A

RNA

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7
Q

Genetic material that has catalytic ability, can self replicate

A

Ribozymes

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8
Q

____________ has produced self replicating RNA molecules

A

Natural selection

-RNA molecules that were more stable or replicated more quickly would have left the most descendent RNA molecules

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9
Q

What are the three key RNA functions?

A
  • ability to store information
  • capacity for self replication
  • enzymatic function - ribozymes

*** DNA and proteins do not have all three functions!

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10
Q

The absolute age of fossils can be determined by…

A

Radiometric dating

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11
Q

Which eon includes the origin of earth?

A

Hadean

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12
Q

Which eon includes organisms that live in extreme conditions and prokaryotes?

A

Archaean

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13
Q

Which eon includes single celled eukaryotes, and multicellular eukaryotes?

A

Proterozoic

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14
Q

Which eon includes the three eras paleozoic, mesozoic, and Cenozoic?

A

Phanerozoic

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15
Q

What are the four eons in geologic record?

A
  • Haden
  • archaean
  • Proterozoic
  • Phanerozoic
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16
Q

What are the three eras in the phanerozoic eon?

A
  • Paleozoic
  • mesozoic
  • cenozoic
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17
Q

What era includes fungi, land plants, fish, and amphibians?

A

Paleozoic era

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18
Q

Which era includes more advanced plants, and reptiles?

A

Mesozoic

19
Q

Which era includes mammals, birds, and pollinating insects?

A

Cenozoic

20
Q

Layered rocks that form when certain prokaryotes bind thin films of sediment together.

A

Stromatolites

21
Q

What did the oxygen revolution cause?

A

Extinction of many prokaryotic groups

Some groups survived in adapted using cellular respiration to harvest energy

22
Q

What were the earths sole inhabitants for 1.5 billion years?

A

Prokaryotes-The first single celled organisms on earth

23
Q

What theory proposes that mitochondria and plastids (chloroplast and related organelles) were formally small prokaryotes living within larger host cells?

A

Endosymbiont theory

24
Q

What are the oldest known fossils of multicellular eukaryotes?

A

Small algae

25
Q

What happened with the rise of multicellularity?

A
  • Evolution of eukaryotic cells allowed for a greater range of unicellular forms
  • The second wave of diversification occurred that gave rise to algae, plants, fungi, and animals
26
Q

Refers to the sudden appearance of fossils resembling modern animal phyla in the Cambrian period

A few animal phyla appear even earlier: sponges, cnidarians, and molluscs

A

Cambrian explosion

27
Q

This provides the first evidence of predator-prey interactions

A

Cambrian explosion

28
Q

Plants and _______ today form mutually beneficial associations and likely colonized land together

A

Fungi

29
Q

What happened in colonization of land?

A

Fungi, plants, and animals begin to colonize land about 50 million years ago

Vascular tissue implants transports materials internally and appeared about 420 million years ago

Arthropods in tetrapod are the most widespread and diverse and animals

30
Q

What are some key events in earth’s history?

A
  • The first single-celled organisms
  • photosynthesis and the oxygen revolution
  • The first eukaryotes
  • The origin of multicellularity
  • Cambrian explosion
  • colonization of land
31
Q

Theory that earths crust is composed of plates floating on earth mantle

A

Plate tectonics theory

32
Q

How does continental drift affect species?

A

Leads to allopatric speciation***

33
Q

What are consequences of continental drift?

A
  • deepening of ocean basins
  • A reduction in shallow water habitat
  • A colder and drier climate inland
34
Q

The fossil records shows that most species that have ever lived are now _______

A

Extinct

Extinction can be caused by changes to a species environment

35
Q

At times when the rate of extinction has increased dramatically it is called a _______ extinction.

This is due to disruptive global environmental changes

A

Mass

36
Q

In each of the five mass extinction events, more than _______% of Earth’s species became extinct

A

50

37
Q

The _____________ extinction defines the boundary between the Paleozoic and Mesozoic eras

This mass extinction occurred in less than 5 million years and caused the extinction of about _____% of marine animal species

A

Permian

96

38
Q

What are some factors that might have contributed to extinction?

A
  • intense volcanism in what is now Siberia
  • Global warming resulting from the omission of large amounts of CO2 from the volcanoes
  • oceanic anoxia from reduce mixing of ocean waters
39
Q

What extinction separates the Mesozoic from the Cenozoic era?

Organisms that went extinct include about half of the marine species and many terrestrial plants and animals, including most dinosaurs

Probable meteorite impact that caused dust clouds to block sunlight and disturb global climate

The Chicxulub Crater off the coast of Mexico is evidence of a meteorite that dates to the same time

A

Cretaceous mass extinction

40
Q

Scientists estimate that the current rate of extinction is ______ to _______times the typical background rate

Extinction rates tend to increase when global temperatures increase

A

100-1,000

41
Q

You can take from ____ to _____ million years for diversity to recover following a mass extinction

The percentage of marine organisms that were predators increase after the permian and cretaceous mass extensions

Mass extinctions can pave the way for adaptive ___________. This can create new species.

A

5 to 100

Radiations

42
Q

The evolution of diversely adaptive species from a common ancestor

This may follow

  • mass extinctions
  • The evolution of novel characteristics
  • The colonization of new regions
A

Adaptive radiations

43
Q

Can occur when organisms colonize new environments with little competition

A

Regional Adaptive radiations

Ex:Hawaiian islands