Question 1

The chemical composition of the gases surrounding the Earth has changed substantially over the past 4 billion years.One notable change was due to the emergence of photosynthetic organisms.The process of photosynthesis increased the amount of what gas in the atmosphere?

Accepted Answer

A)  Carbon dioxide (CO2) .
B)  Nitrogen (N2) .
C)  Hydrogen sulfide (H2SO4) .
D)  Oxygen (O2) .
E)  Water vapor (H2O) .F) B) and E)
G) B) and C)

Question 2

How did the earliest single celled microorganisms produce energy to drive metabolic processes?

Accepted Answer

A)  Aerobic cellular respiration.
B)  Anaerobic cellular respiration.
C)  Sulfuric acid respiration.
D)  Both aerobic and anaerobic cellular respiration.
E)  Sulfuric acid,aerobic and anaerobic respiration.F) B) and D)
G) A) and B)

Question 3

A scientist found an unweathered igneous rock that contained 0.025 g of potassium-40 and 0.075 g of argon-40.Using the table above,how old would you estimate the rock to be?

Accepted Answer

A)  2.6 billion years old.
B)  0.050 billion years old.
C)  1.3 billion years old.
D)  0.001875 billion years olD.
E)  1.69 billion years old.F) B) and D)
G) D) and E)

Question 4

Which situation would be most likely to form a fossil under normal environmental conditions?

Accepted Answer

A)  An elephant that died at the edge of a waterhole.
B)  A bird that died and fell to the forest floor.
C)  A slug that died in leaf litter.
D)  A jellyfish that died in an estuary.E) A) and C)
F) None of the above

Question 5

In eukaryotes,genes involved in transcription and translation are derived from ___________.

Accepted Answer

A)  ancient bacteria
B)  primitive RNA
C)  archaeal ancestors
D)  mitochondrial genomesE) A) and C)
F) B) and C)

Question 6

Which would be most likely to be fossilized?

Accepted Answer

A)  a common large worm
B)  a common thick-shelled crustacean
C)  an herbaceous plant that is only found at very high altitudes
D)  a rare,desert-dwelling lizardE) A) and B)
F) B) and C)

Question 7

Which macromolecule do the majority of scientists favor as the "first" to be found in protobionts?

Accepted Answer

A)  DNA.
B)  RNA.
C)  Amino acids.
D)  Proteins.E) B) and D)
F) A) and C) B

Question 8

The first bilateral animal emerged during the Ordovician Period.Fossils of this organism were discovered in South Africa.

Accepted Answer

A) True 
 B)False

Question 9

Bartel and Szostak hypothesized that among a large pool of RNA molecules,some of them may contain the enzymatic ability to catalyze a covalent bond between nucleotides;these can be selected for in the laboratory.The chart above shows the results from their experiment.The x-axis shows the original pool and 10 pools that were derived from their tagging of RNA with specific enzymatic functions;the y-axis shows the rate of phosphoester (covalent) bond formation.Was their hypothesis supported by this experiment and why?

Accepted Answer

A)  Yes,because pools 1 to 10 show a continual increase in covalent bond formation.
B)  Yes,because the original pool shows some covalent bonds were formed.
C)  No,because there is only a slight increase from the original pool to the first experimental pool.
D)  No,because chemical selection would only increase the rate of covalent bond formation in the first few pools.E) B) and C)
F) C) and D)

Question 10

The process by which the major land masses have shifted their positions,changed shapes and separated from each other,is known as

Accepted Answer

A)  cotranslational sorting.
B)  continental drift.
C)  depolarization of land masses.
D)  differential land movement.
E)  cyclic land drift.F) All of the above
G) B) and D)

Question 11

Changes that have occurred in living organisms over the past four billion years are due primarily to

Accepted Answer

A)  extinction of species.
B)  continental drift.
C)  changes in atmospheric composition.
D)  interaction of genetic and environmental changes.
E)  floods and formation of glaciers.F) A) and B)
G) A) and C)

Question 12

Toward the end of the Proterozoic eon,multicellular animals emerged.The first animals were

Accepted Answer

A)  Fish.
B)  Reptiles.
C)  Invertebrates.
D)  Chordates.
E)  Tetrapods.F) A) and D)
G) A) and C) C

Question 13

Study of the origin of life has resulted in the breakdown of cellular development into overlapping stages,beginning with the synthesis of precursor molecules for the synthesis of nucleotides and amino acids and ending in polymers enclosed in membranes acquiring cellular properties.Which of these stages were a focus of study for Miller and Urey in their FIRST experiment?

Accepted Answer

A)  Stage 1: Nucleotides and amino acids were produced prior to the existence of cells.
B)  Stage 2: Nucleotides became polymerized to form RNA and/or DNA,and amino acids became polymerized to form proteins.
C)  Stage 3: Polymers became enclosed in membranes.
D)  Stage 4: Polymers enclosed in membranes acquired cellular properties.
E)  Stage 5: Ribosomes were developed inside the membranE.F) A) and E)
G) All of the above

Question 14

Although not well understood,the Cambrian Explosion most likely occurred due to changes in sea level and continental drift.

Accepted Answer

A) True 
 B)False

Question 15

You know that RNA is likely the first macromolecule to be enclosed by a membrane,partly because it has the ability to store information and can self-replicate.What else is necessary for simple metabolic processes to occur in a timely manner?

Accepted Answer

A)  A biological catalyst.
B)  Energy from ADP.
C)  A pump,to drive a concentration gradient.
D)  A more stable nucleic aciD.
E)  The ability to carry out structural roles.F) C) and D)
G) B) and E) A

Question 16

Protobionts are thought to be the first nonliving structures that evolved into living cells.A critical characteristic of a protobiont that is found in both modern day prokaryotes and eukaryotes is

Accepted Answer

A)  internal compartments that subdivide metabolic functions.
B)  a boundary membrane that separates external from internal environments.
C)  the ability to exclude all organic substances.
D)  the ability to fuse with any other protobiont for reproduction.
E)  the ability to recognize other protobionts for developmental purposes.F) C) and E)
G) B) and C)

Question 17

You uncovered a fossil that you suspect is around 100 million years old.Which of the radioisotope pairs in the table below could you eliminate as an appropriate choice for radioisotope dating the accompanying rock?

Accepted Answer

A)  Potassium-40/Argon-40 (half-life = 1.3 billion years;useful dating range =100,000-4.5 billion years) 
B)  Rubidium-87/Strontium-87 (half-life = 47 billion years;useful dating range = 10 million-4) 5 billion years) 
C)  Uranium-235/Lead-207 (half-life = 710 million years;useful dating range = 10 million-4.5 billion years) 
D)  Carbon-14/Nitrogen-14 (half-life = 5,730 years;useful dating range = 100-50,000 years) 
E)  Uranium-238/Lead-206 (half-life 4.5 billion years;useful dating range = 10 million-4.5 billion years) F) C) and D)
G) A) and B)

Question 18

The event called the Cambrian Explosion resulted in an abrupt increase in

Accepted Answer

A)  volcanic activity.
B)  diversity of major animal groups.
C)  algal diversity.
D)  the number and size of glaciers.
E)  rate of continental drift.F) All of the above
G) B) and C)

Question 19

The major opposition to the Extraterrestrial Hypothesis is ...

Accepted Answer

A)  not enough organic carbon molecules could have been transported to the Earth's surface by comets and asteroids.
B)  most organic carbon molecules,including nucleic acids and amino acids,would have been destroyed by the intense heating that occurs when large bodies fall through the Earth's atmosphere.
C)  not enough comets and asteroids hit the Earth to deliver organic carbon molecules to the surface.
D)  most of the organic carbon molecules would have fallen into the seas,helping life form in the water but not on the lanD.
E)  without oxygen in the atmosphere the organic carbons that did fall would have been rapidly reduced to inorganic carbon compounds.F) A) and B)
G) A) and E)

Question 20

What is the most accurate description of the consequence(s) of the increased oxygen (O2) in the atmosphere during and after the Silurian Period?

Accepted Answer

A)  Conquest of land by arthropods.
B)  Conquest of land by arthropods and vertebrates.
C)  Increases in animal body sizes and appearance of shelled organisms.
D)  Conquest of land by arthropods and vertebrates,and plants.
E)  Conquest of land by arthropods and vertebrates and an increase in animal body sizes.F) B) and E)
G) D) and E)

Exam 18: Origin and History of Life

The chemical composition of the gases surrounding the Earth has changed substantially over the past 4 billion years.One notable change was due to the emergence of photosynthetic organisms.The process of photosynthesis increased the amount of what gas in the atmosphere?

Correct Answer
verified

How did the earliest single celled microorganisms produce energy to drive metabolic processes?

Correct Answer
verified

A scientist found an unweathered igneous rock that contained 0.025 g of potassium-40 and 0.075 g of argon-40.Using the table above,how old would you estimate the rock to be?

Correct Answer
verified

Which situation would be most likely to form a fossil under normal environmental conditions?

Correct Answer
verified

In eukaryotes,genes involved in transcription and translation are derived from ___________.

Correct Answer
verified

Which would be most likely to be fossilized?

Correct Answer
verified

Which macromolecule do the majority of scientists favor as the "first" to be found in protobionts?

Correct Answer
verified
B

The first bilateral animal emerged during the Ordovician Period.Fossils of this organism were discovered in South Africa.

Correct Answer
verified

Correct Answer
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The process by which the major land masses have shifted their positions,changed shapes and separated from each other,is known as

Correct Answer
verified

Changes that have occurred in living organisms over the past four billion years are due primarily to

Correct Answer
verified

Toward the end of the Proterozoic eon,multicellular animals emerged.The first animals were

Correct Answer
verified
C

Correct Answer
verified

Although not well understood,the Cambrian Explosion most likely occurred due to changes in sea level and continental drift.

Correct Answer
verified

You know that RNA is likely the first macromolecule to be enclosed by a membrane,partly because it has the ability to store information and can self-replicate.What else is necessary for simple metabolic processes to occur in a timely manner?

Correct Answer
verified
A

Protobionts are thought to be the first nonliving structures that evolved into living cells.A critical characteristic of a protobiont that is found in both modern day prokaryotes and eukaryotes is

Correct Answer
verified

You uncovered a fossil that you suspect is around 100 million years old.Which of the radioisotope pairs in the table below could you eliminate as an appropriate choice for radioisotope dating the accompanying rock?

Correct Answer
verified

The event called the Cambrian Explosion resulted in an abrupt increase in

Correct Answer
verified

The major opposition to the Extraterrestrial Hypothesis is ...

Correct Answer
verified

What is the most accurate description of the consequence(s) of the increased oxygen (O₂) in the atmosphere during and after the Silurian Period?

Correct Answer
verified

Exam 18: Origin and History of Life

The chemical composition of the gases surrounding the Earth has changed substantially over the past 4 billion years.One notable change was due to the emergence of photosynthetic organisms.The process of photosynthesis increased the amount of what gas in the atmosphere?

Correct AnswerverifiedShow Answer

How did the earliest single celled microorganisms produce energy to drive metabolic processes?

Correct AnswerverifiedShow Answer

A scientist found an unweathered igneous rock that contained 0.025 g of potassium-40 and 0.075 g of argon-40.Using the table above,how old would you estimate the rock to be?

Correct AnswerverifiedShow Answer

Which situation would be most likely to form a fossil under normal environmental conditions?

Correct AnswerverifiedShow Answer

In eukaryotes,genes involved in transcription and translation are derived from ___________.

Correct AnswerverifiedShow Answer

Which would be most likely to be fossilized?

Correct AnswerverifiedShow Answer

Which macromolecule do the majority of scientists favor as the "first" to be found in protobionts?

Correct AnswerverifiedB

The first bilateral animal emerged during the Ordovician Period.Fossils of this organism were discovered in South Africa.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

The process by which the major land masses have shifted their positions,changed shapes and separated from each other,is known as

Correct AnswerverifiedShow Answer

Changes that have occurred in living organisms over the past four billion years are due primarily to

Correct AnswerverifiedShow Answer

Toward the end of the Proterozoic eon,multicellular animals emerged.The first animals were

Correct AnswerverifiedC

Correct AnswerverifiedShow Answer

Although not well understood,the Cambrian Explosion most likely occurred due to changes in sea level and continental drift.

Correct AnswerverifiedShow Answer

You know that RNA is likely the first macromolecule to be enclosed by a membrane,partly because it has the ability to store information and can self-replicate.What else is necessary for simple metabolic processes to occur in a timely manner?

Correct AnswerverifiedA

Protobionts are thought to be the first nonliving structures that evolved into living cells.A critical characteristic of a protobiont that is found in both modern day prokaryotes and eukaryotes is

Correct AnswerverifiedShow Answer

You uncovered a fossil that you suspect is around 100 million years old.Which of the radioisotope pairs in the table below could you eliminate as an appropriate choice for radioisotope dating the accompanying rock?

Correct AnswerverifiedShow Answer

The event called the Cambrian Explosion resulted in an abrupt increase in

Correct AnswerverifiedShow Answer

The major opposition to the Extraterrestrial Hypothesis is ...

Correct AnswerverifiedShow Answer

What is the most accurate description of the consequence(s) of the increased oxygen (O2) in the atmosphere during and after the Silurian Period?

Correct AnswerverifiedShow Answer

Correct Answer
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B

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C

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A

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What is the most accurate description of the consequence(s) of the increased oxygen (O₂) in the atmosphere during and after the Silurian Period?

Correct Answer
verified