Question 1

Homo sapiens have existed on earth for 2% of the earth's history.

Accepted Answer

A) True 
 B)False  False

Question 2

How would the hydrolysis of phosphodiester bonds impede the origin of life?

Accepted Answer

A)  It would slow the rate of protein synthesis.
B)  It would prevent the assembly of nucleic acids.
C)  It would stop the formation of cell membranes.
D)  It would digest amino acids.E) A) and D)
F) A) and B)

Question 3

If a scientist found very high concentrations of organic biomarkers deep inside a 3.9 billion year old meteorite, how would this effect the explanation of the origins of life on Earth?

Accepted Answer

A)  This would prove the extra-terrestrial origin of life.
B)  This would provide evidence for the extra-terrestrial origin of life.
C)  This would disprove the terrestrial origin of life.
D)  This would provide evidence for the uniqueness of life on earth.E) C) and D)
F) B) and C)

Question 4

How did humans colonize the New World?

Accepted Answer

A)  Early humans walked across a land bridge during periods of lowered sea level.
B)  Christopher Columbus and a host of other explorers were the first to colonize the Americas.
C)  Humans drifted across the Atlantic on primitive canoes.
D)  Humans were present during the break-up of Gondwana.E) None of the above
F) A) and D)

Question 5

The oldest microfossils are of

Accepted Answer

A)  prokaryotes.
B)  eukaryotes.
C)  insects.
D)  pollen grains.E) A) and D)
F) A) and B) A

Question 6

Which one of the following statements about endosymbiosis and the origin of the eukaryotic cell is FALSE?

Accepted Answer

A)  Mitochondria are the descendants of purple bacteria.
B)  The chloroplasts of red and green algae are the descendants of cyanobacteria.
C)  Algae incorporated prokaryotic cells that became chloroplasts, but never acquired mitochondria.
D)  Many compartments of the eukaryotic cell are derived from the endomembrane system.E) B) and C)
F) A) and B)

Question 7

Two principal organelles in eukaryotes that were apparently derived from different types of bacteria are the

Accepted Answer

A)  microfilaments and microtubules.
B)  mitochondria and chloroplasts.
C)  rough ER and smooth ER.
D)  plasma membrane and nuclear membrane.E) B) and D)
F) All of the above

Question 8

Why is a reducing atmosphere conducive to the origin of life?

Accepted Answer

A)  It is more favorable for the development of organic molecules.
B)  It is rich in free oxygen.
C)  It is devoid of organic molecules.
D)  It is very similar to today's atmosphere.E) None of the above
F) B) and C)

Question 9

True multicellularity is a major characteristic of

Accepted Answer

A)  all eukaryotes and a few prokaryotes.
B)  animals and plants only.
C)  eukaryotes only.
D)  protists, plants, and animals.E) B) and C)
F) C) and D)

Question 10

A scientist is analyzing air bubbles trapped in ancient rocks that can be used to understand the ancient atmosphere.What do you expect the scientist will observe when comparing rocks younger than 3.8 billion years old to rocks older than 3.8 billion years?

Accepted Answer

A)  The ratio of the carbon-12 isotope will be lower in the younger rocks, because living organisms preferentially use carbon-12 over other isotopes.
B)  The younger rocks will have higher levels of carbon dioxide, because there was no carbon dioxide in the atmosphere before animals evolved and expelled it as waste.
C)  The ratio of carbon-12 will be lower in the older rocks, because carbon-12 had to build up on earth before life could evolve.
D)  The amount of carbon will vary unpredictably in the younger rocks, because rock weathering added carbon dioxide to the atmosphere, and volcanic activity sequestered it.E) B) and C)
F) A) and D)

Question 11

The early Earth's reducing atmosphere probably contained all of the following except

Accepted Answer

A)  carbon dioxide.
B)  water.
C)  oxygen.
D)  hydrogen sulfide.E) A) and B)
F) A) and D)

Question 12

During the snowball earth temperatures at the equator rarely exceeded -20 degrees Celsius.Why didn't heat from the sun melt the ice?

Accepted Answer

A)  The high levels of atmospheric moisture created extensive cloud cover.
B)  Ice reflected most of radiant energy.
C)  The ozone layer absorbed all the heat.
D)  The earth's core was cooled and kept the ice frozen.E) None of the above
F) A) and D)

Question 13

The group that probably gave rise to chloroplasts is the

Accepted Answer

A)  cyanobacteria.
B)  green photosynthetic bacteria.
C)  purple sulfur bacteria.
D)  non-sulfur purple bacteria.E) B) and D)
F) A) and D)

Question 14

Which of the following was produced in experiments on primitive Earth conditions conducted by Miller-Urey and others?

Accepted Answer

A)  ammonia and water
B)  amino acids
C)   CO2 and H2O
D)   ammonia and hydrogen sulfideE) None of the above
F) B) and C)

Question 15

Eukaryotic cells acquired mitochondria and chloroplasts by

Accepted Answer

A)  endosymbiosis.
B)  exocytosis.
C)  pinocytosis.
D)  mutation.E) A) and D)
F) None of the above

Question 16

Why is there free oxygen in the air?

Accepted Answer

A)  Organisms need oxygen to manufacture ATP.
B)  Free oxygen has been present since the formation of the earth's atmosphere.
C)  Evaporation of the oceans liberated oxygen.
D)  It is a by-product of photosynthesis.E) A) and B)
F) B) and C)

Question 17

What would result for global climate from a massive drop in atmospheric carbon dioxide?

Accepted Answer

A)  An increase in ocean temperature
B)  Increased rock weathering
C)  A decrease in surface temperature
D)  Increased nitrogen availabilityE) A) and B)
F) None of the above C

Question 18

A scientist is studying endosymbiosis in cells.This means she is investigating

Accepted Answer

A)  how mitochondria and chloroplasts were derived from eukaryotic cells.
B)  how mitochondria and chloroplasts were derived from prokaryotic cells.
C)  how mitochondria and chloroplasts evolved into eukaryotic cells.
D)  how mitochondria and chloroplasts evolved into prokaryotic cells.E) A) and B)
F) A) and C)

Question 19

Vascular plants appeared about 450 million year ago.Vascular plants have existed on earth for ______.

Accepted Answer

A)  10% of its history
B)  20% of its history
C)  50% of its history
D)  75% of its historyE) B) and C)
F) A) and D)

Question 20

RNA was probably the first molecule used to encode genetic information; the use of DNA came later.This is due to RNA's inherent stability and its ability to store information more accurately than DNA.

Accepted Answer

A) True 
 B)False

Exam 26: The Origin and Diversity of Life

Homo sapiens have existed on earth for 2% of the earth's history.

Correct AnswerverifiedFalse

How would the hydrolysis of phosphodiester bonds impede the origin of life?

Correct AnswerverifiedShow Answer

If a scientist found very high concentrations of organic biomarkers deep inside a 3.9 billion year old meteorite, how would this effect the explanation of the origins of life on Earth?

Correct AnswerverifiedShow Answer

How did humans colonize the New World?

Correct AnswerverifiedShow Answer

The oldest microfossils are of

Correct AnswerverifiedA

Which one of the following statements about endosymbiosis and the origin of the eukaryotic cell is FALSE?

Correct AnswerverifiedShow Answer

Two principal organelles in eukaryotes that were apparently derived from different types of bacteria are the

Correct AnswerverifiedShow Answer

Why is a reducing atmosphere conducive to the origin of life?

Correct AnswerverifiedShow Answer

True multicellularity is a major characteristic of

Correct AnswerverifiedShow Answer

A scientist is analyzing air bubbles trapped in ancient rocks that can be used to understand the ancient atmosphere.What do you expect the scientist will observe when comparing rocks younger than 3.8 billion years old to rocks older than 3.8 billion years?

Correct AnswerverifiedShow Answer

The early Earth's reducing atmosphere probably contained all of the following except

Correct AnswerverifiedShow Answer

During the snowball earth temperatures at the equator rarely exceeded -20 degrees Celsius.Why didn't heat from the sun melt the ice?

Correct AnswerverifiedShow Answer

The group that probably gave rise to chloroplasts is the

Correct AnswerverifiedShow Answer

Which of the following was produced in experiments on primitive Earth conditions conducted by Miller-Urey and others?

Correct AnswerverifiedShow Answer

Eukaryotic cells acquired mitochondria and chloroplasts by

Correct AnswerverifiedShow Answer

Why is there free oxygen in the air?

Correct AnswerverifiedShow Answer

What would result for global climate from a massive drop in atmospheric carbon dioxide?

Correct AnswerverifiedC

A scientist is studying endosymbiosis in cells.This means she is investigating

Correct AnswerverifiedShow Answer

Vascular plants appeared about 450 million year ago.Vascular plants have existed on earth for ______.

Correct AnswerverifiedShow Answer

RNA was probably the first molecule used to encode genetic information; the use of DNA came later.This is due to RNA's inherent stability and its ability to store information more accurately than DNA.

Correct AnswerverifiedShow Answer

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False

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A

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C

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