BIO 19 (3)
a single species that has evolved into several different forms that live in different ways has undergone
adaptive radiation
the mesozoic era occured
after the paleozoic era
which of the following was not characteristic of earth before the oceans formed?
an atmosphere containing oxygen gas
what prevents organic molecules from forming on thier own and remaining intact today?
atmospheric oxygen is too reactive
the first organisms on earth were most like todays
bacteria
in the past, mass extinction encouraged the rapid evoultion of surviving species
by making new habitats available to them
earths most recent era is the
cenozoic
the process by which 2 species, for example, a flower and a pollinating insect, evolve in response to changes in each other over time is called
coevolution
the endosymbiotic theory proposes that eukaryotic cells arose from
communities formed by prokaryotes
early in earths history, while the planet was in a melted state, the most dense elements formed earths
core
during the jurassic and cretaceous periods, the dominant land animals were
dinosaurs
a fossilized dinosaur, found with fossils of the flowering plants tht it ate, must have lived
during the mesozoic era
which of these labels for fossils in a museum display contains an error?
early mammal (middle paleozioc)
example of fossils include preserved
eggs, footprints, and body parts
after precambrian time, the basic divisions of the geological time scale, from larger to smaller are
eras and periods
during the mesozioc era, animals began to invade the land
false
scientists use geologic dating to determine the absolute age of a rock in years
false
the cenozioc era included the cretaccous, jurassic, and triassic period
false
the vast majority of earths history - about 88% - is taken up by the cenozoic era
false
the leght of time required for half of the radioactive atoms in a sample to decay is its
half - life
to compare the relative ages of fossils, scientists sometimes use an easily recognized species calles an
index fossil
in addition to hydrogen, the gases used in miller and ureys experiment were
methane and ammonia
the fossil record shows that
modern organisms have unicellular ancestors, fossils occur in a particular order, most organisms that ever lived on earth are now extinct
what proportion of all species that have ever lived has become extinct?
more than 99%
a very large mass extinction in which amphibians and trilobites disappeared ocurred at teh end of the
paleozoic era
fossilized evidence of earths first forms of life would consist of
prokaryotes from the precambrian
the cambrian explsion resulted in the evolution of the first
representatives of most animal phyla
when oxygen was first released in the early seas, it combined with iron to form
rust
most fossils form in
sedimentary rock
to be useful as an index fossil, a species must have existed for a
short period over a wide geographical range
sedimentary rock is formed from
small particles of sand, silt, and clay
what was the response of the various groups of early organisms that existed when oxygen levels rose in the atmosphere?
some life forms became extinct, son survived only lin a few airless habitats, some evouved metabolic pathways that used oxygen for respiration
what does fossil evidence indicate about the order in which these 3 vertebrates evolved: bony fish with a jaw, a jawless fish, and a fish with leglike fins?
the fish with leglike fins was the last to evolve
one necessary condition for the evolution of the first life on earth was
the presence of liquid water
the galapagos finches underwent adaptive radiation, a process in which a small group evolves into several different forms that live in different ways
true
how would you date a sample of rock that yo ususpect as being one of the earliest on earth?
use a radioactive isotope with a long half - life
why did oceans not exist on earth nearly 4 billion years ago?
water remained a gas because earth way very hot
miller and ureys experiments attempted to demonstrate
whether organic molecules could have formed before life was present