Which gas was least abundant in Earthʹs early atmosphere, prior to 2
billion years ago?
A) O2
B) CO2
C) CH4
D)
H2O
E) NH3
A
In their laboratory simulations of the early Earth, Miller and Urey
observed the abiotic
synthesis of
A) amino acids.
B)
complex organic polymers.
C) DNA.
D) liposomes.
E)
genetic systems.
A
Which of the factors below weaken the hypothesis of abiotic synthesis
of organic monomers
in early Earthʹs atmosphere?
1. the
relatively short time between intense meteor bombardment and
appearance of the
first life forms
2. the lack of
experimental evidence that organic monomers can form by abiotic
synthesis
3. uncertainty about which gases comprised early
Earthʹs atmosphere
A) 1
B) 2
C) 3
D) 1 and
3
E) 2 and 3
D
) Which of the following has not yet been synthesized in laboratory
experiments studying
the origin of life?
A)
liposomes
B) liposomes with selectively permeable
membranes
C) oligopeptides and other oligomers
D)
protobionts that use DNA to program protein synthesis
E) amino acids
D
In what way were conditions on the early Earth of more than 3 billion
years ago different
from those on todayʹs Earth?
A) Only
early Earth had water vapor in its atmosphere.
B) Only early
Earth was intensely bombarded by large space debris.
C) Only
early Earth had an oxidizing atmosphere.
D) Less ultraviolet
radiation penetrated Earthʹs early atmosphere.
E) Earthʹs early
atmosphere had significant quantities of ozone.
B
What is true of the amino acids that might have been delivered to
Earth within
carbonaceous chondrites?
A) They had the same
proportion of L and D isomers as Earth does today.
B) The
proportion of the amino acids was similar to those produced in the
Miller-Urey
experiment.
C) There were fewer kinds of amino
acids on the chondrites than are found in living
organisms
today.
D) They were delivered in the form of polypeptides.
B
Which of the following is the correct sequence of these events in the
origin of life?
I. formation of protobionts
II. synthesis of
organic monomers
III. synthesis of organic polymers
IV.
formation of DNA-based genetic systems
A) I, II, III, IV
B)
I, III, II, IV
C) II, III, I, IV
D) IV, III, I, II
E)
III, II, I, IV
C
Which is a defining characteristic that all protobionts had in
common?
A) the ability to synthesize enzymes
B) a
surrounding membrane or membrane-like structure
C) RNA
genes
D) a nucleus
E) the ability to replicate RNA
B
Although absolute distinctions between the ʺmost evolvedʺ protobiont
and the first living
cell are unclear, biologists generally agree
that one major difference is that the typical
protobiont could
not
A) possess a selectively permeable membrane boundary.
B)
perform osmosis.
C) grow in size.
D) perform controlled,
precise reproduction.
E) absorb compounds from the external environment
D
The first genes on Earth were probably
A) DNA produced by
reverse transcriptase from abiotically produced RNA.
B) DNA
molecules whose information was transcribed to RNA and later
translated in
polypeptides.
C) auto-catalytic RNA
molecules.
D) RNA produced by autocatalytic, proteinaceous
enzymes.
E) oligopeptides located within protobionts.
C
RNA molecules can both carry genetic information and be catalytic.
This supports the
proposal that
A) RNA was the first
hereditary information.
B) protobionts had an RNA
membrane.
C) RNA could make energy.
D) free nucleotides
would not have been necessary ingredients in the synthesis of
new
RNA molecules.
E) RNA is a polymer of amino acids.
A
What probably accounts for the switch to DNA-based genetic systems
during the evolution
of life on Earth?
A) DNA is chemically
more stable and replicates with fewer errors (mutations)
than
RNA.
B) Only DNA can replicate during cell
division.
C) RNA is too involved with translation of proteins and
cannot provide multiple
functions.
D) DNA forms the
rod-shaped chromosomes necessary for cell division.
E)
Replication of RNA occurs too slowly
A
The synthesis of new DNA requires the prior existence of
oligonucleotides to serve as
primers. On Earth, these primers are
small RNA molecules. This latter observation is
evidence in
support of the hypothesized existence of
A) a snowball
Earth.
B) earlier genetic systems than those based on
DNA.
C) the abiotic synthesis of organic monomers.
D) the
delivery of organic matter to Earth by meteors and comets.
E) the
endosymbiotic origin of mitochondria and chloroplasts.
B
Several scientific laboratories across the globe are involved in
research concerning the
origin of life on Earth. Which of these
questions is currently the most problematic and
would have the
greatest impact on our understanding if we were able to answer
it?
A) How can amino acids, simple sugars, and nucleotides be
synthesized abiotically?
B) How can RNA molecules catalyze
reactions?
C) How did RNA sequences come to carry the code for
amino acid sequences?
D) How could polymers involving lipids
and/or proteins form membranes in aqueous
environments?
E)
How can RNA molecules act as templates for the synthesis of
complementary RNA
molecules?
C
) Several scientific laboratories across the globe are involved in
research concerning the
origin of life on Earth. Which graph
below, if the results were produced abiotically, would
have the
greatest promise for revealing important information about the origin
or Earthʹs
first genetic system?
B
If natural selection in a particular environment favored genetic
systems that permitted the
production of daughter ʺcellsʺ that
were genetically dissimilar from the mother ʺcells,ʺ then
one
should expect selection for
I. polynucleotide polymerase with low
mismatch error rates.
II. polynucleotide polymerases without
proofreading capability.
III. batteries of efficient
polynucleotide repair enzymes.
IV. polynucleotide polymerases
with proofreading capability.
V. polynucleotide polymerases with
high mismatch error rates.
A) I only
B) I and IV
C) I,
III, and IV
D) II and V
E) II, III and V
D
If relatively small carbonaceous chondrites from space were a
significant source of Earthʹs
original amino acids, then which
two of these would have been most important in
permitting their
organic materials to survive impact with Earth?
I. Carbonaceous
chondrites must contain no D-amino acids.
II. Earthʹs early
atmosphere must have had little free oxygen.
III. The chondrites
must have arrived on Earth before 4.2 billion years ago.
IV.
Earthʹs early atmosphere must have been dense enough to dramatically
slow the
chondrites before they impacted.
V. The chondrites
must have impacted land, rather than a large body of water.
A) I
& II
B) II & III
C) II & IV
D) II &
V
E) III & IV
C
If the half-life of carbon-14 is about 5,730 years, then a fossil
that has one-sixteenth the
normal proportion of carbon-14 to
carbon-12 should be about how many years old?
A) 1,400
B)
2,800
C) 11,200
D) 16,800
E) 22,400
E
Which measurement would help determine absolute dates by radiometric
means?
A) the accumulation of the daughter isotope
B) the
loss of parent isotopes
C) the loss of daughter isotopes
D)
all three of these
E) only A and B
E
How many half-lives should have elapsed if 6.25% of the parent
isotope remains in a fossil
at the time of analysis?
A)
one
B) two
C) three
D) four
E) five
D
Approximately how far back in time does the fossil record
extend?
A) 6,000 years
B) 3,500,000 years
C) 6,000,000
years
D) 3,500,000,000 years
E) 5,000,000,000,000 years
D
) Assuming that the rate of sea-floor spreading was constant during
the 1-million-year
period depicted above, Earthʹs magnetic field
has undergone reversal at an average rate of
once every
A)
10,000 years.
B) 25,000 years.
C) 100,000 years.
D)
250,000 years.
E) 1,000,000 years
D
If a particular marine organism is fossilized in the sediments
immediately overlying the
igneous rock at the arrow labeled ʺII,ʺ
at which other location, labeled A—E, would a
search be most
likely to find more fossils of this organism?
A) A
B)
B
C) C
D) D
E) E
C
Earthʹs current magnetic field is the same as it had been when which
sea-floor areas
solidified?
I. area B
II. area
C
III. area D
IV. area E
A) I only
B) II
only
C) I and II
D) I and III
E) II and IV
E
Assuming that the rate of sea-floor spreading was constant during the
1-million-year
period depicted above, what should be the
approximate age of marine fossils found in
undisturbed
sedimentary rock immediately overlying the igneous rock at the arrow
labeled
ʺIIʺ?
A) 10,000 years
B) 250,000 years
C)
500,000 years
D) 1,000,000 years
C
Argon-40, the daughter isotope of potassium-40, is a gas. Elemental
potassium has an
atomic mass of about 39. If the submersible
robot (which is equipped with a drill that is
long enough to get
to the igneous rock) ascends from depth too quickly, gases
trapped
within igneous rock may rapidly expand, fracture the
rock, and escape from the sample
before it can be dated aboard
the floating research vessel. Rock samples can also absorb
argon
gas. Which of these techniques has the highest chance of providing
inaccurate dates
of igneous rocks distant from the rift valley,
and what type of inaccuracy would it cause?
A) if the date of the
rock is determined by comparing the ratio of potassium-40
to
potassium-39, underestimation of age
B) if the
submersible robot is retrieved from the sea floor at a very slow
speed,
overestimation of age
C) if the submersible robot is
equipped with a decompression chamber for the
samples,
underestimation of age
D) if the submersible robot
keeps the sample in a chamber of pure argon at high
pressure,
overestimation of age
D
What is true of the fossil record of mammalian origins?
A) It is
a good example of punctuated equilibrium.
B) It shows that
mammals and birds evolved from the same kind of dinosaur.
C) It
includes transitional forms with progressively specialized
teeth.
D) It indicates that mammals and dinosaurs did not overlap
in geologic time.
E) It includes a series that shows the gradual
change of scales into fur.
C
If a fossil is encased in a stratum of sedimentary rock without any
strata of igneous rock
(e.g., lava, volcanic ash) nearby, then it
should be
A) easy to determine the absolute age of the fossil,
because the radioisotopes in the
sediments will not have been
ʺresetʺ by the heat of the igneous rocks.
B) easy to determine
the absolute age of the fossil, because the igneous rocks will
not
have physically obstructed the deposition of sediment of a
single age next to the
fossil.
C) difficult to determine the
absolute age of the fossil, because the ʺmarker fossilsʺ
common
to igneous rock will be absent.
D) difficult to determine the
absolute age of the fossil, because radiometric dating
of
sedimentary rock is less accurate than that of igneous rock.
D
Letʹs say that a hypothetical submersible robot was used to collect
samples of sedimentary
rock from the sea floor along the section
illustrated. The robot moved back and forth along
the transect,
collecting first from site A, then site III, then site B, then site
II, and lastly site
D. Assuming that sedimentation has occurred
at a constant rate along the transect over the
past million
years, rearrange the sites mentioned above on the basis of the
thickness of the
sediments overlying the igneous rock, from
thickest to thinnest.
A) A, B, II, D, III
B) I, II,
III
C) III, II, D, B, A
D) III, A, II, B, D
E) III, D,
II, B, A
E
An early consequence of the release of oxygen gas by plant and
bacterial photosynthesis
was to
A) make life on land
difficult for aerobic organisms.
B) change the atmosphere from
oxidizing to reducing.
C) make it easier to maintain reduced
molecules.
D) cause iron in ocean water and terrestrial rocks to
rust (oxidize).
E) prevent the formation of an ozone layer.
D
Arrange these events from earliest to most recent.
1. emission
of lava in what is now Siberia at time of Permian extinctions
2.
emission of lava that solidified at the same time as iron-bearing
terrestrial rocks began
to rust
3. emission of lava that
solidified at the same time as rusted iron precipitated
from
seawater
4. emission of lava in what is now India at
time of Cretaceous extinctions
A) 3, 1, 2, 4
B) 3, 2, 1,
4
C) 3, 1, 4, 2
D) 1, 3, 2, 4
E) 1, 2, 3, 4
B
) Which free-living cells were the earliest contributors to the
formation of Earthʹs oxidizing
atmosphere?
A)
cyanobacteria
B) chloroplasts
C) mitochondria
D)
seaweeds
E) endosymbionts
A
Which of the following statements provides the strongest evidence
that prokaryotes
evolved before eukaryotes?
A) the primitive
structure of plants
B) meteorites that have struck Earth
C)
abiotic laboratory experiments that produced liposomes
D)
Liposomes closely resemble prokaryotic cells.
E) The oldest
fossilized cells resemble prokaryotes.
E
What is thought to be the correct sequence of these events, from
earliest to most recent, in
the evolution of life on
Earth?
1. origin of mitochondria
2. origin of multicellular
eukaryotes
3. origin of chloroplasts
4. origin of
cyanobacteria
5. origin of fungal-plant symbioses
A) 4, 3,
2, 1, 5
B) 4, 1, 2, 3, 5
C) 4, 1, 3, 2, 5
D) 4, 3, 1,
5, 2
E) 3, 4, 1, 2, 5
C
If it were possible to conduct sophisticated microscopic and chemical
analyses of
microfossils found in 3.2-billion-year-old
stromatolites, then within such microfossils, one
should be
surprised to observe evidence of:
I. double-stranded DNA
II.
a nuclear envelope
III. a nucleoid
IV. a nucleolus
V.
nucleic acids
A) II only
B) III only
C) II and
IV
D) II, III, and IV
E) all five of these
C
Recent evidence indicates that the first major diversification of
multicellular eukaryotes
may have coincided in time with
the
A) origin of prokaryotes.
B) switch to an oxidizing
atmosphere.
C) melting that ended the ʺsnowball Earthʺ
period.
D) origin of multicellular organisms.
E) massive
eruptions of deep-sea vents.
C
Which of these observations fails to support the endosymbiotic theory
for the origin of
eukaryotic cells?
A) the existence of
structural and molecular differences between the plasma
membranes
of prokaryotes and the internal membranes of
mitochondria and chloroplasts
B) the existence of size
differences between the cytosolic ribosomes of eukaryotes and
the
ribosomes within mitochondria and chloroplasts
C) the existence
of size differences between some prokaryotic cells and
mitochondria
D) the existence of rRNA sequence differences
between the cytosolic ribosomes of
eukaryotes and the ribosomes
within mitochondria and chloroplasts
A
) Which event is nearest in time to the end of the period known as
snowball Earth?
A) oxygenation of Earthʹs seas and
atmosphere
B) evolution of mitochondria
C) Cambrian
explosion
D) evolution of true multicellularity
E) Permian extinction
C
The snowball Earth hypothesis provides a possible explanation for
the
A) diversification of animals during the late
Proterozoic.
B) oxygenation of Earthʹs seas and
atmosphere.
C) colonization of land by plants and fungi.
D)
origin of O2-releasing photosynthesis.
E) existence of
prokaryotes around hydrothermal vents on the ocean floor.
A
If two continental land masses converge and are united, then the
collision should cause
A) a net loss of intertidal zone and
coastal habitat.
B) the extinction of any species adapted to
intertidal and coastal habitats.
C) an overall decrease in the
surface area located in the continental interior.
D) a decrease
in climatic extremes in the interior of the new
super-continent.
E) the maintenance of the previously existing
ocean currents and wind patterns.
A
A major evolutionary episode that corresponds in time most closely
with the formation of
Pangaea was the
A) origin of
humans.
B) Cambrian explosion.
C) Permian
extinctions.
D) Pleistocene ice ages.
E) Cretaceous extinctions.
C
On the basis of their morphologies, how might Linnaeus have
classified the Hawaiian
silverswords?
A) He would have
placed them all in the same species.
B) He would have classified
them the same way that modern botanists do.
C) He would have
placed them in more species than modern botanists do.
D) He would
have used evolutionary relatedness as the primary criterion for
their
classification.
E) Both B and D are correct.
C
Anatomically, what was true of Lystrosaurus?
A) Its jaw would
have been hinged the same way as the jaws of the early reptiles
were
hinged.
B) It was a tetrapod.
C) It had thin,
moist skin without scales.
D) Its dentition (tooth pattern) was
typical of modern mammals.
E) It would have had no temporal
fenestra in its skull.
B
Which of Lystrosaurusʹ features help explain why these organisms
fossilized so abundantly?
I. the presence of hard parts, such as
tusks
II. its herbivorous diet
III. its persistence across
at least two geological eras
IV. its widespread geographic
distribution
V. its mixture of reptilian and mammalian
features
A) I and III
B) III and V
C) III and V
D)
I, III, and IV
E) II, III, IV, and V
D
Which of these is the most likely explanation for the modern-day
distribution of
dicynodont fossils?
A) There had been two
previous super-continents that existed at different times
long
before the Permian period.
B) The dicynodonts were
evenly distributed throughout all of Pangaea.
C) The dicynodonts
were distributed more abundantly throughout Gondwanaland
than
throughout any other land mass.
D) The dicynodonts were
able to swim long distances, up to thousands of kilometers.
E)
The dicynodonts could survive for periods of months aboard ʺraftsʺ of
vegetation,
which carried them far and wide, but not to the
northern hemisphere.
C
) The observation that tusks were limited to males in several
species, and were apparently
not used in food-gathering, is
evidence that the tusks probably
A) were used by males during the
sex act.
B) served as heat-dissipation structures.
C) are
homologous to claws.
D) were insignificant to the survival and/or
reproduction of dicynodonts.
E) were maintained as the result of
sexual selection.
E
Which of these is the most likely explanation for the existence of
dicynodont fossils on
modern-day Antarctica?
A) They arrived
there aboard ʺraftsʺ of vegetation, and quickly adapted to the
bitterly
cold climate.
B) Earthʹs polar regions were once so
warm (especially immediately after the ʺsnowball
Earth periodʺ)
that reptiles and mammal-like reptiles flourished there.
C) The
landmass that is now the Antarctic continent was formerly located at
a
more-northerly position, and was also united to other
landmasses.
D) Dicynodonts originated on the island continent of
Antarctica and went extinct as the
continent migrated to its
current position at the South Pole.
C
Dicynodonts survived the Permian extinction and, therefore, existed
during both the
A) Paleozoic and Mesozoic eras.
B)
Proterozoic and Archaean eons.
C) Proterozoic and Phanerozoic
eons.
D) Mesozoic and Cenozoic eras.
E) Carboniferous and
Permian periods.
A
) There are at least a dozen known species in the extinct genus
Lystrosaurus. If each species
was suited to a quite different
environment, then this relatively large number of species
is
likely due to
A) sexual selection.
B) adaptive
radiation.
C) heterochrony.
D) polyploidy.
E) species selection.
B
0) The dicynodonts survived the mass extinction that was most closely
correlated in time, if
not in cause, with
A) snowball
Earth.
B) a large (10 km) meteor striking the Earth.
C) an
intense period of sun-spot formation, with subsequent increase in
solar radiation.
D) the formation of Pangaea and lava flows that
covered large portions of Pangaea.
E) the pleistocene Ice Age.
D
The dicynodonts that survived the Permian extinction would initially
have had to endure
(or escape from) the physical effects of
__________, and subsequently, the biological effects
of
__________.
A) warm temperatures, decreased metabolism
B)
arid conditions, disease
C) meteorite shock waves, lack of
food
D) increased sea level, lack of freshwater
E) volcanic
ash in the atmosphere, increased predation
E
If an increase in dicynodont species diversity (i.e., number of
species) occurred soon after
the Permian extinction, and if it
occurred for the same general reason usually given for
the
increase in mammalian diversity following the Cretaceous
extinction, then it should be
attributed to
A) an innovation
among the dicynodonts that allowed them to fill brand new
niches.
B) the availability of previously occupied
niches.
C) the extinction of the dinosaurs (except the
birds).
D) the evolution of humans.
B
Fossilized stromatolites
A) all date from 2.7 billion years
ago.
B) formed around deep-sea vents.
C) resemble structures
formed by bacterial communities that are found today in
some
warm, shallow, salty bays.
D) provide evidence that
plants moved onto land in the company of fungi around 500
million
years ago.
E) contain the first undisputed fossils of eukaryotes
and date from 2.1 billion years ago.
C
) The oxygen revolution changed Earthʹs environment dramatically.
Which of the following
adaptations took advantage of the presence
of free oxygen in the oceans and atmosphere?
A) the evolution of
cellular respiration, which used oxygen to help harvest energy
from
organic molecules
B) the persistence of some animal
groups in anaerobic habitats
C) the evolution of photosynthetic
pigments that protected early algae from the corrosive
effects of
oxygen
D) the evolution of chloroplasts after early protists
incorporated photosynthetic
cyanobacteria
E) the evolution
of multicellular eukaryotic colonies from communities of prokaryotes
A
Select the factor most likely to have caused the animals and plants
of India to differ greatly
from species in nearby Southeast
Asia.
A) The species have become separated by convergent
evolution.
B) The climates of the two regions are
similar.
C) India is in the process of separating from the rest
of Asia.
D) Life in India was wiped out by ancient volcanic
eruptions.
E) India was a separate continent until 55 million
years ago.
E
Adaptive radiations can be a direct consequence of four of the
following five factors. Select
the exception.
A) vacant
ecological niches
B) genetic drift
C) colonization of an
isolated region that contains suitable habitat and few
competitor
species
D) evolutionary innovation
E) an
adaptive radiation in a group of organisms (such as plants) that
another group
uses as food
B
A genetic change that caused a certain Hox gene to be expressed along
the tip of a
vertebrate limb bud instead of farther back helped
to make possible the evolution of the
tetrapod limb. This type of
change is illustrative of
A) the influence of environment on
development.
B) paedomorphosis.
C) a change in a
developmental gene or in its regulation that altered the
spatial
organization of body parts.
D) heterochrony.
E)
gene duplication.
C
Which of the following steps has not yet been accomplished by
scientists studying the
origin of life?
A) synthesis of
small RNA polymers by ribozymes
B) abiotic synthesis of
polypeptides
C) formation of molecular aggregates with
selectively permeable membranes
D) formation of protobionts that
use DNA to direct the polymerization of amino acids
E) abiotic
synthesis of organic molecules
D
A swim bladder is a gas-filled sac that helps fish maintain buoyancy.
The evolution of the
swim bladder from lungs of an ancestral fish
is an example of
A) an evolutionary trend.
B)
paedomorphosis.
C) exaptation.
D) adaptive
radiation.
E) changes in the Hox gene expression
C