GL101 Exam Preparation Newest Actual Exam With Complete Questions And
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Question 1
The Precambrian (Hadean, Archean, and Proterozoic Eons) accounts for which of the following
proportions of Earth's history?
A) The first 8% of Earth history
B) The segment of geologic time prior to uniformitarianism taking effect
C) All of the periods after the Permian
D) The first 88% of Earth history and the geologic time scale
E) The time during which all modern life forms evolved
Correct Answer: D) the first 88% of Earth history and the geologic time scale
Rationale: The Precambrian represents the vast majority of Earth's existence, spanning
from the formation of the planet approximately 4.6 billion years ago to the beginning of the
Cambrian Period about 541 million years ago. It is divided into three eons: the Hadean,
Archean, and Proterozoic. Despite its length, the fossil record for this era is sparse
compared to the Phanerozoic Eon, which makes up only the remaining 12% of Earth's
history.
Question 2
Which of the following sequences correctly represents the order of "fossil succession" through
geologic time, from oldest to youngest?
A) Multicelled organisms, hardbodied marine invertebrates, first land plants, dinosaurs,
mammals
B) Flowering plants, birds, reptiles, first trees, first fishes, blue green algae
C) One-celled organisms, first fishes, first amphibians, reptiles, dinosaurs
D) Land plants, insects, marine plants, trilobites, humans
E) Mammals, dinosaurs, land plants, hardbodied invertebrates, multicelled organisms
Correct Answer: A) multicelled organisms, hardbodied marine invertebrates, first land
plants, dinosaurs, mammals
Rationale: Fossil succession follows a specific chronological order: life began as simple
single cells, moved to multicelled organisms (Late Precambrian), then developed hard parts
like shells (Cambrian Explosion), transitioned to land (Silurian/Devonian), flourished
during the age of reptiles/dinosaurs (Mesozoic), and finally saw the rise of mammals
(Cenozoic). Option A is the only sequence that moves forward correctly through the
requested strata.
Question 3
Which theory is currently the leading hypothesis describing the formation of the Sun, Earth, and
other planets of the solar system?
A) The Planoassemblar Theory
B) The Nebular Theory
, 2
C) The Astrostellar Theory
D) The Solar Flareup Hypothesis
E) The Big Bang Theory
Correct Answer: B) nebular
Rationale: The Nebular Theory proposes that the solar system formed about 4.6 billion
years ago from the gravitational collapse of a giant interstellar cloud of gas and dust (a
nebula). As the cloud contracted, it began to rotate and flatten into a disk; the Sun formed
at the center, while the planets accreted from the remaining material in the disk.
Question 4
Which of the following processes describes how Earth's core was formed?
A) A massive nickel-iron asteroid acted as a nucleus upon which Earth condensed.
B) High-density radioactive carbon concentrated in the center of the planet.
C) Leftover nickel and iron that did not fit into the crust and mantle were squeezed into the
center.
D) Molten iron and nickel separated from silicates and sank due to their higher density.
E) Intense pressure at the surface forced heavy metals inward toward the center.
Correct Answer: D) molten iron and nickel separated from silicates and sank due to its
higher density
Rationale: Early in Earth's history, the planet was sufficiently molten for "planetary
differentiation" to occur. Gravity pulled high-density materials, primarily iron and nickel,
toward the center to form the core. Lighter, less dense silicate minerals "floated" toward
the exterior to form the mantle and the crust.
Question 5
In the early 20th century, which scientist argued forcefully for the concept of "continental drift"?
A) Karl Wagner
B) Edwin Rommel
C) Alfred Wegener
D) Alfred the Great
E) Charles Lyell
Correct Answer: C) Alfred Wegener
Rationale: In 1912, Alfred Wegener proposed the Continental Drift hypothesis, suggesting
that the continents were once joined in a single supercontinent and had since moved apart.
Although he provided evidence like matching coastlines and fossils, his theory was initially
rejected because he could not provide a viable physical mechanism for how the continents
moved.
Question 6
What was Pangaea?
A) A large ocean basin that opened in the Triassic and closed in the Paleocene.
, 3
B) A large Precambrian shield area in Africa and South America.
C) A huge mountain range formed by the collision of Africa and Europe.
D) A supercontinent that formed in the late Paleozoic and broke apart in Triassic time.
E) The first volcanic island arc formed in the Pacific Ocean.
Correct Answer: D) a super continent that formed in the late Paleozoic and broke apart in
Triassic time
Rationale: Pangaea was a massive supercontinent that incorporated almost all of Earth's
landmasses. It finished assembling during the Permian period and began to rifts and break
apart during the Triassic, eventually leading to the configuration of the continents we see
today.
Question 7
What was the name of Wegener's supercontinent that began to break up approximately 200
million years ago?
A) Gondwanaland
B) Laurasia
C) Pangaea
D) Rodinia
E) Columbia
Correct Answer: C) Pangaea
Rationale: While Gondwanaland and Laurasia were smaller sub-supercontinents (the
southern and northern halves of Pangaea, respectively), and Rodinia was a much older
supercontinent, Pangaea is the specific name Wegener gave to the global landmass of the
late Paleozoic and early Mesozoic.
Question 8
According to Wegener’s evidence, where was southern Africa located during the Late Paleozoic?
A) Near the North Pole
B) 30° south of the Equator
C) Along the Equator
D) Over the South Pole
E) In the center of the Pacific Ocean
Correct Answer: D) over the south pole
Rationale: Wegener used paleoclimatic evidence to support his theory. He found evidence of
massive continental glaciation in southern Africa, South America, India, and Australia
dating to the late Paleozoic. This suggested these landmasses were grouped together over
the South Pole at that time.
Question 9
Which layer of the Earth forms the relatively cool, brittle plates described in plate tectonics?
A) The Asthenosphere
, 4
B) The Lithosphere
C) The Astrosphere
D) The Eosphere
E) The Mesosphere
Correct Answer: B) lithosphere
Rationale: The lithosphere is the outermost physical layer of the Earth, consisting of the
crust and the uppermost, rigid part of the mantle. It is brittle and broken into numerous
plates that move over the more ductile, plastic asthenosphere below.
Question 10
What is a typical rate of lithospheric (tectonic) plate movement?
A) 2 metres per year
B) 0.1 centimetres per year
C) 20 metres per year
D) 5 centimetres per year
E) 1 kilometre per year
Correct Answer: D) 5 centimetres per year
Rationale: Tectonic plates move very slowly, typically ranging from about 1 to 15
centimeters per year. An average rate of 5 cm per year is roughly the same rate at which
human fingernails grow. This slow movement over millions of years accounts for the vast
distances continents have drifted.
Question 11
At which type of plate boundary is new seafloor created?
A) Convergent plate boundaries
B) Divergent plate boundaries
C) Transform plate boundaries
D) Hot spot boundaries
E) Subduction zones
Correct Answer: B) divergent
Rationale: At divergent boundaries (such as mid-ocean ridges), tectonic plates move away
from each other. As they separate, magma rises from the mantle to fill the gap, cools, and
solidifies to form new oceanic crust (seafloor spreading).
Question 12
Which of the following is the thinnest layer of the Earth?
A) The Crust
B) The Outer Core
C) The Mantle
D) The Inner Core
E) The Lithosphere
Correct Detailed Answers (Verified Answers) |Already Graded A+
Question 1
The Precambrian (Hadean, Archean, and Proterozoic Eons) accounts for which of the following
proportions of Earth's history?
A) The first 8% of Earth history
B) The segment of geologic time prior to uniformitarianism taking effect
C) All of the periods after the Permian
D) The first 88% of Earth history and the geologic time scale
E) The time during which all modern life forms evolved
Correct Answer: D) the first 88% of Earth history and the geologic time scale
Rationale: The Precambrian represents the vast majority of Earth's existence, spanning
from the formation of the planet approximately 4.6 billion years ago to the beginning of the
Cambrian Period about 541 million years ago. It is divided into three eons: the Hadean,
Archean, and Proterozoic. Despite its length, the fossil record for this era is sparse
compared to the Phanerozoic Eon, which makes up only the remaining 12% of Earth's
history.
Question 2
Which of the following sequences correctly represents the order of "fossil succession" through
geologic time, from oldest to youngest?
A) Multicelled organisms, hardbodied marine invertebrates, first land plants, dinosaurs,
mammals
B) Flowering plants, birds, reptiles, first trees, first fishes, blue green algae
C) One-celled organisms, first fishes, first amphibians, reptiles, dinosaurs
D) Land plants, insects, marine plants, trilobites, humans
E) Mammals, dinosaurs, land plants, hardbodied invertebrates, multicelled organisms
Correct Answer: A) multicelled organisms, hardbodied marine invertebrates, first land
plants, dinosaurs, mammals
Rationale: Fossil succession follows a specific chronological order: life began as simple
single cells, moved to multicelled organisms (Late Precambrian), then developed hard parts
like shells (Cambrian Explosion), transitioned to land (Silurian/Devonian), flourished
during the age of reptiles/dinosaurs (Mesozoic), and finally saw the rise of mammals
(Cenozoic). Option A is the only sequence that moves forward correctly through the
requested strata.
Question 3
Which theory is currently the leading hypothesis describing the formation of the Sun, Earth, and
other planets of the solar system?
A) The Planoassemblar Theory
B) The Nebular Theory
, 2
C) The Astrostellar Theory
D) The Solar Flareup Hypothesis
E) The Big Bang Theory
Correct Answer: B) nebular
Rationale: The Nebular Theory proposes that the solar system formed about 4.6 billion
years ago from the gravitational collapse of a giant interstellar cloud of gas and dust (a
nebula). As the cloud contracted, it began to rotate and flatten into a disk; the Sun formed
at the center, while the planets accreted from the remaining material in the disk.
Question 4
Which of the following processes describes how Earth's core was formed?
A) A massive nickel-iron asteroid acted as a nucleus upon which Earth condensed.
B) High-density radioactive carbon concentrated in the center of the planet.
C) Leftover nickel and iron that did not fit into the crust and mantle were squeezed into the
center.
D) Molten iron and nickel separated from silicates and sank due to their higher density.
E) Intense pressure at the surface forced heavy metals inward toward the center.
Correct Answer: D) molten iron and nickel separated from silicates and sank due to its
higher density
Rationale: Early in Earth's history, the planet was sufficiently molten for "planetary
differentiation" to occur. Gravity pulled high-density materials, primarily iron and nickel,
toward the center to form the core. Lighter, less dense silicate minerals "floated" toward
the exterior to form the mantle and the crust.
Question 5
In the early 20th century, which scientist argued forcefully for the concept of "continental drift"?
A) Karl Wagner
B) Edwin Rommel
C) Alfred Wegener
D) Alfred the Great
E) Charles Lyell
Correct Answer: C) Alfred Wegener
Rationale: In 1912, Alfred Wegener proposed the Continental Drift hypothesis, suggesting
that the continents were once joined in a single supercontinent and had since moved apart.
Although he provided evidence like matching coastlines and fossils, his theory was initially
rejected because he could not provide a viable physical mechanism for how the continents
moved.
Question 6
What was Pangaea?
A) A large ocean basin that opened in the Triassic and closed in the Paleocene.
, 3
B) A large Precambrian shield area in Africa and South America.
C) A huge mountain range formed by the collision of Africa and Europe.
D) A supercontinent that formed in the late Paleozoic and broke apart in Triassic time.
E) The first volcanic island arc formed in the Pacific Ocean.
Correct Answer: D) a super continent that formed in the late Paleozoic and broke apart in
Triassic time
Rationale: Pangaea was a massive supercontinent that incorporated almost all of Earth's
landmasses. It finished assembling during the Permian period and began to rifts and break
apart during the Triassic, eventually leading to the configuration of the continents we see
today.
Question 7
What was the name of Wegener's supercontinent that began to break up approximately 200
million years ago?
A) Gondwanaland
B) Laurasia
C) Pangaea
D) Rodinia
E) Columbia
Correct Answer: C) Pangaea
Rationale: While Gondwanaland and Laurasia were smaller sub-supercontinents (the
southern and northern halves of Pangaea, respectively), and Rodinia was a much older
supercontinent, Pangaea is the specific name Wegener gave to the global landmass of the
late Paleozoic and early Mesozoic.
Question 8
According to Wegener’s evidence, where was southern Africa located during the Late Paleozoic?
A) Near the North Pole
B) 30° south of the Equator
C) Along the Equator
D) Over the South Pole
E) In the center of the Pacific Ocean
Correct Answer: D) over the south pole
Rationale: Wegener used paleoclimatic evidence to support his theory. He found evidence of
massive continental glaciation in southern Africa, South America, India, and Australia
dating to the late Paleozoic. This suggested these landmasses were grouped together over
the South Pole at that time.
Question 9
Which layer of the Earth forms the relatively cool, brittle plates described in plate tectonics?
A) The Asthenosphere
, 4
B) The Lithosphere
C) The Astrosphere
D) The Eosphere
E) The Mesosphere
Correct Answer: B) lithosphere
Rationale: The lithosphere is the outermost physical layer of the Earth, consisting of the
crust and the uppermost, rigid part of the mantle. It is brittle and broken into numerous
plates that move over the more ductile, plastic asthenosphere below.
Question 10
What is a typical rate of lithospheric (tectonic) plate movement?
A) 2 metres per year
B) 0.1 centimetres per year
C) 20 metres per year
D) 5 centimetres per year
E) 1 kilometre per year
Correct Answer: D) 5 centimetres per year
Rationale: Tectonic plates move very slowly, typically ranging from about 1 to 15
centimeters per year. An average rate of 5 cm per year is roughly the same rate at which
human fingernails grow. This slow movement over millions of years accounts for the vast
distances continents have drifted.
Question 11
At which type of plate boundary is new seafloor created?
A) Convergent plate boundaries
B) Divergent plate boundaries
C) Transform plate boundaries
D) Hot spot boundaries
E) Subduction zones
Correct Answer: B) divergent
Rationale: At divergent boundaries (such as mid-ocean ridges), tectonic plates move away
from each other. As they separate, magma rises from the mantle to fill the gap, cools, and
solidifies to form new oceanic crust (seafloor spreading).
Question 12
Which of the following is the thinnest layer of the Earth?
A) The Crust
B) The Outer Core
C) The Mantle
D) The Inner Core
E) The Lithosphere
