Question 1

Refer to the figure below showing a simplified time line of the origin of life.  Which event could have occurred between the existence of the "RNA world" and the evolution of the first cells?

Accepted Answer

A)   The production of oxygen by cyanobacteria
B)   The rise of lipid bilayer membranes
C)   The prebiotic synthesis of ribonucleotides
D)   Photosynthesis
E)   Complementary base pairing between nitrogenous basesF) B) and E)
G) B) and C)

Question 2

Which is an example of a nucleotide?

Accepted Answer

A)   
B)   
C)   
D)   
E)   F) All of the above
G) C) and E)

Question 3

J.William Schopf's discovery of chemical evidence of photosynthesis indicated that he had found chains and clumps of _______ in rocks in Australia that are 3.5 billion years old.

Accepted Answer

The answer of J.William Schopf's discovery of chemical evidence of...

Question 4

Following the initial Miller-Urey experiment, new evidence indicated that major volcanic eruptions would have released carbon dioxide, nitrogen, hydrogen sulfide, and sulfur dioxide into the atmosphere of early Earth.When these gasses were incorporated into an experiment similar to the first, the experiment produced

Accepted Answer

A)   exactly the same chemicals as the first experiment.
B)   fewer types of amino acids than the first experiment.
C)   organic compounds not produced in the first experiment, including 20 amino acids.
D)   no basic small molecules of life.
E)   atmospheric oxygen.F) B) and E)
G) All of the above

Question 5

Experiments indicate that prebiotic synthesis of simple chemicals could have occurred within cold water inclusions in ice.Which of the following is considered a location where this could have occurred?

Accepted Answer

A)   Enceladus, one of Saturn's moons
B)   Ocean environments on ancient Earth
C)   The planet Venus
D)   Magma chambers under Earth's surface
E)   Outer spaceF) None of the above
G) A) and E)

Question 6

A laboratory model of a prebiotic structure that resembles modern cells is called a _______.

Accepted Answer

The answer of A laboratory model of a prebiotic structure...

Question 7

The "backbone" of a nucleic acid molecule is made of

Accepted Answer

A)   nitrogenous bases.
B)   alternating sugar and phosphate groups.
C)   purines.
D)   pyrimidines.
E)   nucleosides.F) A) and B)
G) D) and E)

Question 8

Refer to the figure below, showing two flasks of broth that were prepared and heated to boiling.Immediately after heating, one flask was left open and the other was sealed with a cork.Both flasks were allowed to cool and then left undisturbed for several days.Only one of the flasks developed a cloudy appearance, as shown.  When these results were presented as proof against spontaneous generation, a criticism was raised about the design of the experiment.Which is a valid criticism in this case?

Accepted Answer

A)   The experiment lacked a control.
B)   The heating step was not sufficient to destroy all microorganisms in the broth.
C)   The experiment did not allow enough time for microorganism growth.
D)   The experimental flask was sealed off from two variables: air and microorganisms.
E)   The broth in the two flasks must have differed in microbe content before heating.F) B) and E)
G) C) and D)

Question 9

Meteorites that have come from Mars

Accepted Answer

A)   contain carbonates that are precipitated from aqueous solution, indicating water on Mars.
B)   are loose agglomerations of dust and ice.
C)   contain no organic molecules.
D)   are responsible for all water that occurs on Earth.
E)   contain evidence of cyanobacteria.F) A) and E)
G) C) and E)

Question 10

In 1969, scientists shaved off pieces of the Murchison meteorite and found both D- and L-isomers of ten amino acids.Only L-isomers of amino acids are made by living organisms on Earth.This indicates that

Accepted Answer

A)   Earth's amino acids could not have had an extraterrestrial origin.
B)   the meteorite's amino acids as a whole could not have resulted from contamination by Earth organisms.
C)   basic chemical building blocks of life have only formed on Earth.
D)   life must have originated somewhere other than Earth.
E)   life arose in many places besides Earth.F) A) and D)
G) A) and C)

Question 11

RNA molecules that act as catalysts are called

Accepted Answer

A)   ribozymes.
B)   glycosidic linkages.
C)   chaperonins.
D)   disulfide bridges.
E)   triglycerides.F) D) and E)
G) A) and E)

Question 12

Changes to the original Miller‒Urey hot chemistry experiment included adding other gases like carbon dioxide (CO2) , nitrogen (N2) , hydrogen sulfide (H2S) , and sulfur dioxide (SO2)  in the test apparatus, which resulted in the production of more small molecules of life than the original experiment had produced. Which products were shown to be significant for the evolution of the cellular membrane?

Accepted Answer

A)   All five bases that are present in nucleic acids (i.e., A, T, C, G, and U) 
B)   All of the 20 standard amino acids
C)   Many 3- to 6-carbon sugars
D)   Certain fatty acids
E)   Small carboxylic acidsF) A) and B)
G) A) and C)

Question 13

When searching for life on another planet, the essential molecule(s)  to look for as a sign of life as we know it is/are

Accepted Answer

A)   nucleic acids.
B)   water.
C)   amino acids.
D)   nitrogen.
E)   carbon dioxide.F) A) and D)
G) D) and E)

Question 14

Pasteur disproved spontaneous generation by demonstrating that microorganisms did not grow in broth that was heated in swan-neck flasks and then allowed to sit undisturbed for several days.It was important that he placed the broth in control and experimental flasks before heating rather than transferring the broth to new flasks after heating.Why?

Accepted Answer

A)   The experimental design relied on having the flasks sit undisturbed for an extended time period.
B)   An additional variable could have been introduced into the experiment by including the transferring step.
C)   Microorganisms could have been introduced from the air into the broth during transfer or could have been present in the second flask.
D)   A different flask could have affected the results, so it was important to use only one flask for each sample.
E)   It was critical to have the same volume of broth before and after heating, and the transfer process could have resulted in a loss in volume.F) B) and C)
G) A) and E)

Question 15

Which model represents a structure that was likely a key intermediate in the evolution of life on Earth?

Accepted Answer

A)   
B)   
C)   
D)   
E)   F) A) and C)
G) A) and E)

Question 16

The sequences of DNA that encode specific proteins and are transcribed into RNA are called _______.

Accepted Answer

The answer of The sequences of DNA that encode specific...

Question 17

Suppose scientists develop a protocell with a membrane that allows all molecules to enter or leave the protocell via diffusion.Will this serve the function of a cell membrane?

Accepted Answer

A)   Yes, because it allows molecules to cross down their concentration gradients.
B)   No, because it facilitates molecules moving into and out of the protocell.
C)   Yes, because the phospholipids assemble to form a complete sphere.
D)   No, because it does not maintain an internal environment different from the external environment.
E)   Yes, because it maintains a constant environment.F) A) and C)
G) C) and D)

Question 18

A student claims that the formation of biologically relevant organic compounds during prebiotic simulation experiments does not mean that a similar series of events actually occurred on Earth.Which statement best evaluates this claim?

Accepted Answer

A)   The claim is correct because the simulation experiments were conducted in a lab rather than in a natural setting.
B)   The claim is correct because the simulation experiments were conducted by humans rather than occurring naturally without human interference.
C)   The claim is correct because the simulation experiments may not have accurately simulated the actual conditions present on early Earth.
D)   The claim is incorrect because a simulation can faithfully reproduce conditions as a fair test of whether they could or could not occur.
E)   The claim is incorrect because simulations carried out under laboratory conditions can accurately mimic conditions found in natural settings.F) A) and E)
G) All of the above

Question 19

The idea of spontaneous generation was disproved through experiments by

Accepted Answer

A)   Stanley Miller.
B)   Harold Urey.
C)   Francesco Redi and Louis Pasteur.
D)   Allan Hills.
E)   Johannes van der Waals.F) All of the above
G) B) and E)

Question 20

Which statement about DNA base sequences is true?

Accepted Answer

A)   The more distant the evolutionary relationship between two species, the greater the similarity in their DNA base sequences.
B)   Comparisons of DNA base sequences cannot be used to make inferences about the evolutionary relatedness of two species.
C)   The chimpanzee and human genomes share 18 percent of their DNA base sequences.
D)   Evolutionary relationships between species are more accurately determined by DNA base sequence analysis than by comparisons of physical or behavioral characteristics.
E)   The human genome contains only part of the biological information present in the human body.F) A) and B)
G) B) and E)

Exam 4: Nucleic Acids and the Origin of Life

Which is an example of a nucleotide?

Correct Answer
verified

When searching for life on another planet, the essential molecule(s) to look for as a sign of life as we know it is/are

Correct Answer
verified

Correct Answer
verified

Refer to the figure below showing a simplified time line of the origin of life. Which event could have occurred between the existence of the "RNA world" and the evolution of the first cells?

Correct Answer
verified

The "backbone" of a nucleic acid molecule is made of

Correct Answer
verified

A laboratory model of a prebiotic structure that resembles modern cells is called a _______.

Correct Answer
verified

Correct Answer
verified

RNA molecules that act as catalysts are called

Correct Answer
verified

The sequences of DNA that encode specific proteins and are transcribed into RNA are called _______.

Correct Answer
verified

Suppose scientists develop a protocell with a membrane that allows all molecules to enter or leave the protocell via diffusion.Will this serve the function of a cell membrane?

Correct Answer
verified

A student claims that the formation of biologically relevant organic compounds during prebiotic simulation experiments does not mean that a similar series of events actually occurred on Earth.Which statement best evaluates this claim?

Correct Answer
verified

Experiments indicate that prebiotic synthesis of simple chemicals could have occurred within cold water inclusions in ice.Which of the following is considered a location where this could have occurred?

Correct Answer
verified

Meteorites that have come from Mars

Correct Answer
verified

Correct Answer
verified

Which model represents a structure that was likely a key intermediate in the evolution of life on Earth?

Correct Answer
verified

Which statement about DNA base sequences is true?

Correct Answer
verified

Correct Answer
verified

The idea of spontaneous generation was disproved through experiments by

Correct Answer
verified

In 1969, scientists shaved off pieces of the Murchison meteorite and found both D- and L-isomers of ten amino acids.Only L-isomers of amino acids are made by living organisms on Earth.This indicates that

Correct Answer
verified

J.William Schopf's discovery of chemical evidence of photosynthesis indicated that he had found chains and clumps of _______ in rocks in Australia that are 3.5 billion years old.

Correct Answer
verified

Exam 4: Nucleic Acids and the Origin of Life

Which is an example of a nucleotide?

Correct AnswerverifiedShow Answer

When searching for life on another planet, the essential molecule(s) to look for as a sign of life as we know it is/are

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Refer to the figure below showing a simplified time line of the origin of life. Which event could have occurred between the existence of the "RNA world" and the evolution of the first cells?

Correct AnswerverifiedShow Answer

The "backbone" of a nucleic acid molecule is made of

Correct AnswerverifiedShow Answer

A laboratory model of a prebiotic structure that resembles modern cells is called a _______.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

RNA molecules that act as catalysts are called

Correct AnswerverifiedShow Answer

The sequences of DNA that encode specific proteins and are transcribed into RNA are called _______.

Correct AnswerverifiedShow Answer

Suppose scientists develop a protocell with a membrane that allows all molecules to enter or leave the protocell via diffusion.Will this serve the function of a cell membrane?

Correct AnswerverifiedShow Answer

A student claims that the formation of biologically relevant organic compounds during prebiotic simulation experiments does not mean that a similar series of events actually occurred on Earth.Which statement best evaluates this claim?

Correct AnswerverifiedShow Answer

Experiments indicate that prebiotic synthesis of simple chemicals could have occurred within cold water inclusions in ice.Which of the following is considered a location where this could have occurred?

Correct AnswerverifiedShow Answer

Meteorites that have come from Mars

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which model represents a structure that was likely a key intermediate in the evolution of life on Earth?

Correct AnswerverifiedShow Answer

Which statement about DNA base sequences is true?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

The idea of spontaneous generation was disproved through experiments by

Correct AnswerverifiedShow Answer

In 1969, scientists shaved off pieces of the Murchison meteorite and found both D- and L-isomers of ten amino acids.Only L-isomers of amino acids are made by living organisms on Earth.This indicates that

Correct AnswerverifiedShow Answer

J.William Schopf's discovery of chemical evidence of photosynthesis indicated that he had found chains and clumps of _______ in rocks in Australia that are 3.5 billion years old.

Correct AnswerverifiedShow Answer

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