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Biology 2 > Ch25 > Flashcards

Ch25 Flashcards

1
Q

Protocells

A

-may have been fluid-filled vesicles w/ membrane-like structures
-may have been vesicles w/ RNA capable of replication

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2
Q

Abiotic synthesis

A

creation of organic molecules from non-life

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3
Q

Chemical/physical processes on early earth may have produced simple cells in these stages:

A

-abiotic synthesis
-joining of these small molecules
-packaging molecules into protocells
-origin of self-replicating molecules

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4
Q

Earths atmosphere likely contained

A

-water
-chemicals released by volcanic eruptions (N, nitrogen oxides, CO2, methane, ammonia, H, HS

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5
Q

A. I. Oparin and J.B.S Haldane (1920s)

A

hypothesized that the early atmosphere was reducing the environment

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6
Q

Stanley Miller and Harold Urey(1953)

A

-did experiments that showed that the abiotic synthesis of organic molecules in a reducing atmosphere is possible
-demonstarted that organic molecules have formed with various possible atmosphere

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7
Q

RNA monomers

A

have produced spontaneously from simple molecules

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8
Q

First genetic material

A

probably RNA

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9
Q

RNA

A

could have been the template for DNA

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10
Q

Ribozymes

A

-RNA molecules
-found to catalyze many diff. reactions
-can make complementary copies of short stretched of RNA

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11
Q

Natural selection

A

produced self-replicating RNA molecules

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12
Q

Sedimentary rocks

A

deposited into strata
-richest source of fossils

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13
Q

Fossil record

A

-favors species that: existed for a long time, were abundant/widespread, and had hard parts

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14
Q

Tiktaalik

A

-early terrestrial vertebrate
-filled hole from the jump from water to land

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15
Q

Radiometric dating

A

-can determine absolute ages of fossils
-good for fossils up to 75,000 years old
-

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16
Q

Parent isotope decays into daughter isotope at a constant rate

A
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17
Q

Half-life

A

time required for half the parent isotope to decay

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18
Q

Geologic record

A

-divided into the Archaean, Proterozoic, and Phanerozioc eons
-major boundaries between geological divisions correspond to extinction events in fossil record

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19
Q

Key events in life’s history

A
  • origins of single celled and multicelled organisms
    -colonization of land
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20
Q

Phanerozoic

A

-encompasses multicellular eukaryotic life
-broken down into Paleozoic, Mesozoic, and Cenozoic
-(please more coffee)

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21
Q

order for geologic record

A

-Phanerozic
Cenozoic
Mesozoic
Paleozoic
-Proterozoic
-Archaean

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22
Q

Stromatolites

A

-rocks formed by the accumulation of sedimentary players on bacterial mats
-oldest known fossils
-date back to 3.5 billion years ago

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23
Q

possible order for earth formation

A

-origin of solar system and earth
-prokaryotes
-atmosphere oxygen
-single-celled eukaryotes
-multicellular eukaryotes
-animals
-humans

24
Q

O2

A

-produced by oxygenic photosynthesis reacted w/ dissolved iron and precipitated out to form banded iron formations
-2.7 billion years ago, oxygen accumulated in atmosphere

25
Oxygen revolution
-2.3 -2.7 billion years ago -caused extinction of many prokaryotic groups -some survived and adapted using cellular respiration for energy -likely caused by ancient cyanobacteria
26
endosymbiont theory
proposes mitochondria and plastids were formally small prokaryotes living within a larger host cells
27
Serial endosymbiosis
supposes that mitochondria evolved before plastids through a sequence if endosymbiotic events
28
Evidence supporting endosymbiotic origin of mitochondria and plastids
-inner membranes are similar to plasma membranes -division is similar in these organelles and some prokaryotes -they transcribe/translate own DNA -their ribosomes are more similar to prokaryotic than eukaryotic ribosomes
29
Evolution of eukaryotic cells
allowed for a greater rate of unicellular forms
30
Snowball earth hypothesis
suggests that periods of extreme glaciation confined life to the equatorial region or deep sea vents (750-580 million years ago)
31
Cambrian explosion
refers the sudden appearance of fossils resembling modern animal phyla in Cambrian period -provides first evidence of predator-prey interactions -may have had a long fuse (from China fossils) -DNA analyses suggest that many animal phyla diverged before -fossils in china provide evidence of tens of millions of animal phyla prior to
32
Phylum
-based on body plan -phylogenies (combine morphological, molecular and fossil data)
33
Vascular tissue in plants
-transport materials internally -appeared about 420 million years ago
34
Arthropods and tetrapods
most widespread and diverse land animals
35
Tetrapods
evolved form lobe finned fishes around 365 million years ago
36
extinction events
provided the rise of new species and fall of species
37
Theory of Plate tetonics
Earths crusts is composed of plates floating in Earths mantle
38
Tectonic plates
move slowly through processes of continental dirft -oceanic/continental plates collide, seperate, or slide past each other -interations between plates cause mountains, islands, and earthquakes
39
Continental drift of Pangea
-seperation of land can lead to allopatric sepeciation
40
mass extinction
result of disruptive global environmental changes -asteroid creating Gulf of Mexico and causing volcanic eruptions -can have way for adaptive radiations
41
factors contributed to the 'Big five extinctions"
-intense volcanism in Siberia -global warming resulted from emissions of CO2 from volcanoes (ice caps melted, conveyor belt of current form Pacific Ocean to Atlantic shut down, ocean died, everything in ocean died (extinction) -reduced temp. from equator to poles -oceanic anoxia from reduced mixing of ocean waters
42
Permian extinction
-defines boundary between Paleozoic and Mesozoic eras 251 million years ago -occured in less than 5 million years -caused about 95% of marine animal species
43
Cretaceous mass extinction
-65.5 million years ago -seperated Mesozoic from Cenozoic -half of marine terrestrial plants, and most of dinosaurs went extinct
44
Presence of iridium in sedimentary rocks
-suggests meteorite impact about 65 million years ago (caused dust cloud, covered sun, disturbed global climate) -Gulf of Mexico
45
Extinction rates
tend to increase when global temp. increase
46
adaptive radiation
evolution of diversely adapted species from common ancestors -may follow mass extinctions, evolution of novel characteristics, and colonization of new regions -photosynthetic prokaryotes, large predators in Cambrian, land plants, insects, and tetrapods -can occur when organisms colonize new environments w/ little competition -Hawaii (great ex. of regional adaptive radiation)
47
Heterochrony
evolutionary change in rate/timing of developmental events -can have significant impact on body shape -can alter timing of reproductive development relative to development of nonproductive organs
48
Homeotic genes
-determine where certain features (ex. wings, legs, how flower parts are arranged) will develop on an organism -cause rapid change
49
paedormophosis
rate of reproductive development accerlerates compared with somatic development
50
Causes of rapid changes
-changes in Hox gene
51
Evolutionary novelties
52
Evolutionary trends
-do not imply an intrinsic drive toward a particular phenotype
53
Hox genes
-class of homeotic gene -provide positional info. during development -if expressed in wrong location, then body part will be in wrong location
54
Ubx gene
changes have been identified that can turn off leg development
55
Evolution is like...
..tinkering -process where slight modifications of existing forms cause new forms

Biology 2 (18 decks)

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