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ISB 200 Quiz#1
History of Life
49
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Undergraduate 2
09/21/2009

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Term
Primordial Earth
Definition
the earliest, most ancient stage of Earth's existence
Term
Hadean Earth
Definition
an interval in geologic time, started at Earth's formation 4.6 billion years ago, and ended 3.8 billion years ago-the time interval of the 'Primordial Earth'
Term
Absolute Dating
Definition
geologic time dating based on ratios of radiactive elements in volcanic rocks
Term
Relative Dating
Definition
geologic time dating based on assemblages of fossils that indicate a particular interval in geologic time
Term
Amino Acids
Definition
proteins that are an essential building block of living organisms
Term
Prokaryotic
Definition
simplest cell type with no nucleus, as found in bacteria
Term
Cyanobacteria
Definition
photosynthetic bacteria, composed of prokaryotic cells
Term
Stromatolites
Definition
mounded structures consisting of layers of cyanobacteria and sediment
Term
hypersaline
Definition
extremely salty
Term
Extremophile
Definition
an organism that lives in an extreme, harsh environment
Term
Deep-Sea Hydrothermal Volcanic Vents
Definition
area where volcanic activity along the ocean floor creates living communities, occur in the very deep ocean where no sunlight penetrates
Term
Chemosynthesis
Definition
using chemicals as the basis for life, for example the chemosynthetic bacteria in the deep-sea vents that use sulfur from volcanic activity
Term
Eukaryotic
Definition
more advanced cell type, with a nucleus and complex internal cell structure-the type of cell that forms all multicellular organisms
Term
Yeti Crab
Definition
blind and fuzzy, lives>7,000 ft. down, around volcanic vents in Pacific Ocean
Term
Microbe
Definition
general term for a single-celled form of life
Term
Europa
Definition
a moon of Jupiter
Term
Antarctic icefish
Definition
fish adapted to survive in water that is below freezing
Term
Snowball Earth
Definition
two intervals in Earth's history marked by worldwide glaciation
Term
Ediacaran
Definition
Earliest example of communities of complex multicellular life forms, may not be closely related to laters forms of life
Term
The Cambrian 'Explosion'
Definition
refers to the apparent rapid rise in biodiversity during the Cambrian period, between 510-530 Ma
Term
Arthropods
Definition
trilobites, crustaceans, insects, spiders-the "joint-legged" animals
Term
Echinoderms
Definition
sea-urchins, starfish
Term
Lagerstatten
Definition
geologic deposit marked by exceptional fossil preservation due to a combination of special circumstances
Term
Velvet Worms
Definition
or Onychophorans-unusual small animals with wormlike segmented bodies and jointed legs, may be closely related to weird fossils from the Cambrian
Term
Chordates
Definition
the group that includes all vertebrates (aniimals with a bony skeleton)
Term
Tetrapods
Definition
land vertebrates
Term
Deep Time
Definition
discusses geological time and explains the difference between relative and absolute time. It also includes information about index fossils.
Term
Absolute Dating
Definition
rocks are dated on the basis of radioactive elements in the rocks that break down, or decay from one radioactive form to another. This decay happens at a KNOWN RATE (for example, radioactive potassium decays into radioactive argon). The proportion of “parent” to “daughter: elements can thus be used to date the rock.
Term
Relative Dating
Definition
based on the principle of superposition, which is that if there are layers of deposits, those laid down first will be on the bottom and those laid down last will be on the top.
Term
Basic characteristics of living organisms.
Definition
-Are composed of one or more cells. The basic unit of life
-Can regulate their internal environment.
-Can make energy from nutrients, and dispose of waste products.
-Can change over time in response to changes around them.
-Can respond to stimuli
-Can reproduce
Term
Viruses
Definition
No internal cell structures, can only obtain energy from, and reproduce in, host cells that they infect.
BUT can change and adapt to their surroundings.
Term
When was the Earth formed?
Definition
4.6 Ba
Term
conditions on 'Primordial Earth'
Definition
-No free oxygen
-Very hot temperatures
-Under constant bombardment-No protective atmosphere
-Poisonous chemicals-Methane, Ammonia, Carbon Dioxide
-Lethal levels of UV radiation
-No life forms (at least not yet known)
Term
When was the first fossil evidence of life on Earth found and what was it?
Definition
3.5 Ba fossil cyanobacteria
Term
Lab expirement leading to the formation of amino acids in recreated early Earth environment.
Definition
 Miller-Urey experiments(1950‘s):
Passed energy (electricity) through a closed system with
dissolved gasses representing Earth‘s early atmosphere .
Produces Amino Acids - proteins that are an essential building
block of living organisms.
BUT-we’ve never produces living organisms in lab from non-living components.
Term
Stromalites today
Definition
found today in hyper saline (extremely salty) shallow marine bays along the coast of western Australia.
Term
possible consequence for 'Snowball Earth'
Definition
Virtually all life living on or near earth’s surface wiped out
Term
possible cause for 'Snowball Earth'
Definition
uncertain reduced CO2. Glacial deposits widespread around the world-not just at North and South poles
Term
'Snowball Earth' intervals
Definition
710-640 Ma
Term
'Ediacran' life as first clear examples of complex multicellular life forms
Definition
 -fossils appear approximately 570 Ma
    -First good record of multicellular life - sponge like ,frond like, jellyfish like
-s. Australia, s. Africa, s. America, Newfoundland, Russia, Great Britain
Term
Early examples of familiar groups found after the 'Cambrian Explosion'
Definition
sponges, jellyfish, clams, snails, etc.
Term
Primitive living chordates
Definition
lamprey and hagfish
Term
chordate features
Definition
NOTOCHORD-Dorsal stiffening structure that runs the length of the body
DORSAL NERVE CORD-or spinal chord
GILL SPLITS-Paired series of opening on either side of the body, for respiration
V-SHAPED BODY MUSCLE-Along the trunk of the body, for locomotion
Term
hagfishes
Definition
-Repulsive lifestyle-scavenge on dead carcasses on the seafloor, secrete massive amounts of slimy mucous
Term
lampreys
Definition
Parasitic, using rasping keratin teeth in sucker mouth to scavenge on live animals
Term
Agnathons
Definition
Early jawless fishes
Term
Placoderms
Definition
Early armored jawed fishes
Term
origin of jaws
Definition
modified gill arches
Term
origin of teeth
Definition
modified scales
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