Question 1

The "RNA world" hypothesis proposes that

Accepted Answer

A)  RNA formed from DNA. 
B)  RNA was both a catalyst and genetic material. 
C)  RNA was a catalyst only. 
D)  RNA formed after proteins. 
E)  DNA formed after RNA was broken down. 
A)  RNA formed from DNA. 
B)  RNA was both a catalyst and genetic material. 
C)  RNA was a catalyst only. 
D)  RNA formed after proteins. 
E)  DNA formed after RNA was broken down.

Question 2

In the diagram below, use the base-pairing rules for DNA and RNA to label the strand of RNA (right) that is complementary to the single strand of DNA (left), where C = cytosine, G = guanine, A = adenine, T = thymine, and U = uracil. Then circle and label an example of a nucleotide and a nucleoside, showing the double-stranded DNA and RNA hybrid. Based on the orientation of the sugar molecules, label the four ends of the molecule as 3´ or 5´? showing the double-stranded DNA and RNA hybrid.

Accepted Answer

The answer of In the diagram below, use the base-pairing...

Question 3

In DNA and RNA, nucleotides are joined by

Accepted Answer

A)  phosphodiester linkages. 
B)  hydrogen bonds. 
C)  peptide linkages. 
D)  glycosidic linkages. 
E)  All of the above 
A)  phosphodiester linkages. 
B)  hydrogen bonds. 
C)  peptide linkages. 
D)  glycosidic linkages. 
E)  All of the above

Question 4

DNA carries genetic information in its

Accepted Answer

A)  helical form. 
B)  sequence of bases. 
C)  tertiary sequence. 
D)  sequence of amino acids. 
E)  phosphate groups. 
A)  helical form. 
B)  sequence of bases. 
C)  tertiary sequence. 
D)  sequence of amino acids. 
E)  phosphate groups.

Question 5

Which statement about Miller's "cold chemistry" experiment is false?

Accepted Answer

A)  Biomolecules could be formed from inorganic molecules without an electric spark. 
B)  High temperatures are not required for the synthesis of biomolecules. 
C)  Biomolecules can form even at -100ºC. 
D)  The experiment disproves the possibility that life originated outside the Earth. 
E)  Biomolecules were formed that were not found in the Miller-Urey experiment. 
A)  Biomolecules could be formed from inorganic molecules without an electric spark. 
B)  High temperatures are not required for the synthesis of biomolecules. 
C)  Biomolecules can form even at -100ºC. 
D)  The experiment disproves the possibility that life originated outside the Earth. 
E)  Biomolecules were formed that were not found in the Miller-Urey experiment.

Question 6

DNA with a higher G + C content is more stable at high temperatures than DNA with a high A + T content. Why?

Accepted Answer

A)  G and C fit together better than A and T. 
B)  The two chains assume a parallel orientation when the A + T content is higher. 
C)  The negative charge on the phosphates in the backbone is partially neutralized in DNA with a higher G + C content. 
D)  The hydrophobic interactions between G and C are stronger than those between A and T. 
E)  G and C form three hydrogen bonds and A and T, just two. 
A)  G and C fit together better than A and T. 
B)  The two chains assume a parallel orientation when the A + T content is higher. 
C)  The negative charge on the phosphates in the backbone is partially neutralized in DNA with a higher G + C content. 
D)  The hydrophobic interactions between G and C are stronger than those between A and T. 
E)  G and C form three hydrogen bonds and A and T, just two.

Question 7

The Miller-Urey experiment demonstrated that

Accepted Answer

A)  under specific conditions, the building blocks of life can be formed. 
B)  life on Earth came from other bodies in the solar system. 
C)  CO2, N2, H2S, and SO2 were probably present in Earth's early atmosphere. 
D)  volcanic eruptions may have released CO2, N2, H2S, and SO2 into Earth's early atmosphere. 
E)  ice has been found in meteorites and on Mars. 
A)  under specific conditions, the building blocks of life can be formed. 
B)  life on Earth came from other bodies in the solar system. 
C)  CO2, N2, H2S, and SO2 were probably present in Earth's early atmosphere. 
D)  volcanic eruptions may have released CO2, N2, H2S, and SO2 into Earth's early atmosphere. 
E)  ice has been found in meteorites and on Mars.

Question 8

Replication, transcription, and translation

Accepted Answer

A)  all refer to the synthesis of macromolecules. 
B)  refer to RNA synthesis, DNA synthesis, and protein synthesis, respectively. 
C)  require the synthesis of polysaccharides. 
D)  would be expected to be exergonic reactions. 
E)  all use nucleotides as building blocks. 
A)  all refer to the synthesis of macromolecules. 
B)  refer to RNA synthesis, DNA synthesis, and protein synthesis, respectively. 
C)  require the synthesis of polysaccharides. 
D)  would be expected to be exergonic reactions. 
E)  all use nucleotides as building blocks.

Question 9

What accounts for the stability of the DNA molecule?

Accepted Answer

A)  The bonds between purines and pyrimidines 
B)  Phosphodiester bonds between the nitrogenous bases 
C)  Strong hydrogen bonds between the sugar and phosphate groups 
D)  Its double-helix shape 
E)  The direct bonding of the base to the phosphate molecule 
A)  The bonds between purines and pyrimidines 
B)  Phosphodiester bonds between the nitrogenous bases 
C)  Strong hydrogen bonds between the sugar and phosphate groups 
D)  Its double-helix shape 
E)  The direct bonding of the base to the phosphate molecule

Question 10

The Miller-Urey experiment showed that biological molecules could be made from inorganic precursors. These results

Accepted Answer

A)  support the theory that life's molecules originated outside Earth. 
B)  showed that RNA can catalyze reactions. 
C)  showed that only the L-isomers of amino acids were formed. 
D)  support the chemical evolution theory. 
E)  showed how biopolymers are made. 
A)  support the theory that life's molecules originated outside Earth. 
B)  showed that RNA can catalyze reactions. 
C)  showed that only the L-isomers of amino acids were formed. 
D)  support the chemical evolution theory. 
E)  showed how biopolymers are made.

Question 11

Which of the following is not a nucleotide?

Accepted Answer

A)  Guanosine triphosphate 
B)  Cyclic adenosine monophosphate 
C)  An amino acid 
D)  Adenosine triphospate 
E)  Ribonucleic acid 
A)  Guanosine triphosphate 
B)  Cyclic adenosine monophosphate 
C)  An amino acid 
D)  Adenosine triphospate 
E)  Ribonucleic acid

Question 12

In 1668, Francesco Redi did some experiments to disprove spontaneous generation. He began by putting pieces of meat into identical jars. Some jars were left open to the air, and some were sealed. He then did the same experiment with one variation: instead of sealing the jars completely, he covered them with gauze (which kept out flies while allowing the meat to be exposed to the air). In both experiments, he checked if fly maggots appeared in the meat or not. What hypothesis was being tested?

Accepted Answer

A)  Spontaneous generation is more likely to occur during the hot days of summer. 
B)  Maggots do not arise spontaneously but from eggs laid by adult flies. 
C)  The type of meat affects whether spontaneous generation occurs. 
D)  Spontaneous generation can occur only if air is present. 
E)  Flies will develop from rotting meat if the meat is exposed to air. 
A)  Spontaneous generation is more likely to occur during the hot days of summer. 
B)  Maggots do not arise spontaneously but from eggs laid by adult flies. 
C)  The type of meat affects whether spontaneous generation occurs. 
D)  Spontaneous generation can occur only if air is present. 
E)  Flies will develop from rotting meat if the meat is exposed to air.

Question 13

The double-helix formation of DNA is caused by

Accepted Answer

A)  ionic bonds. 
B)  covalent bonds. 
C)  hydrogen bonds. 
D)  hydrophobic side chains. 
E)  None of the above 
A)  ionic bonds. 
B)  covalent bonds. 
C)  hydrogen bonds. 
D)  hydrophobic side chains. 
E)  None of the above

Question 14

In the double stranded structure of DNA,

Accepted Answer

A)  the two strands are held together by covalent bonds. 
B)  the monomers in each strand are linked together by hydrogen bonds. 
C)  both strands run in the same direction. 
D)  the two strands are held together by hydrogen bonds. 
E)  the interaction among the monomers is random. 
A)  the two strands are held together by covalent bonds. 
B)  the monomers in each strand are linked together by hydrogen bonds. 
C)  both strands run in the same direction. 
D)  the two strands are held together by hydrogen bonds. 
E)  the interaction among the monomers is random.

Question 15

The term used to describe molecules that have both hydrophilic and hydrophobic properties is _______.

Accepted Answer

The answer of The term used to describe molecules that...

Question 16

Nucleotides are composed of

Accepted Answer

A)  amino acids. 
B)  nucleic acids. 
C)  a phosphate, a sugar, and a base. 
D)  a base and phosphate. 
E)  fatty acids and a base. 
A)  amino acids. 
B)  nucleic acids. 
C)  a phosphate, a sugar, and a base. 
D)  a base and phosphate. 
E)  fatty acids and a base.

Question 17

There are several hypotheses considered for the pathway to life. The "replicator first" hypothesis has several problems including

Accepted Answer

A)  RNA cannot be a catalyst. 
B)  polymers of nucleic acid monomers have not been detected in the prebiotic model systems. 
C)  questions about the source of energy for the prebiotic synthesis of RNA. 
D)  DNA is not self-catalytic. 
E)  b, c, and d 
A)  RNA cannot be a catalyst. 
B)  polymers of nucleic acid monomers have not been detected in the prebiotic model systems. 
C)  questions about the source of energy for the prebiotic synthesis of RNA. 
D)  DNA is not self-catalytic. 
E)  b, c, and d

Question 18

Which of the following is not a nucleotide?

Accepted Answer

A)  Adenosine triphosphate 
B)  Guanosine triphosphate 
C)  Cyclic adenosine monophosphate 
D)  Thymine 
E)  All of the above are nucleotides. 
A)  Adenosine triphosphate 
B)  Guanosine triphosphate 
C)  Cyclic adenosine monophosphate 
D)  Thymine 
E)  All of the above are nucleotides.

Question 19

All of the following bases are found in DNA except

Accepted Answer

A)  thymine. 
B)  adenine. 
C)  uracil. 
D)  guanine. 
E)  cytosine 
A)  thymine. 
B)  adenine. 
C)  uracil. 
D)  guanine. 
E)  cytosine

Question 20

What is the evidence supporting the claim that ancient rocks contain the fossils of cells?

Accepted Answer

A)  The imprints of chloroplasts can be seen in the rocks. 
B)  Radioactive tracing of CO2 in the rocks shows similarities to modern cells. 
C)  Microscopic examination of the rocks shows chains of cells that are similar to modern cyanobacteria. 
D)  DNA analysis of the rocks shows similarities to modern cells. 
E)  Pieces of RNA found in the rocks are similar to ribozymes. 
A)  The imprints of chloroplasts can be seen in the rocks. 
B)  Radioactive tracing of CO2 in the rocks shows similarities to modern cells. 
C)  Microscopic examination of the rocks shows chains of cells that are similar to modern cyanobacteria. 
D)  DNA analysis of the rocks shows similarities to modern cells. 
E)  Pieces of RNA found in the rocks are similar to ribozymes.

Exam 4: Nucleic Acids and the Origin of Life

The "RNA world" hypothesis proposes that

In DNA and RNA, nucleotides are joined by

DNA carries genetic information in its

Which statement about Miller's "cold chemistry" experiment is false?

DNA with a higher G + C content is more stable at high temperatures than DNA with a high A + T content. Why?

The Miller-Urey experiment demonstrated that

Replication, transcription, and translation

What accounts for the stability of the DNA molecule?

The Miller-Urey experiment showed that biological molecules could be made from inorganic precursors. These results

Which of the following is not a nucleotide?

The double-helix formation of DNA is caused by

In the double stranded structure of DNA,

The term used to describe molecules that have both hydrophilic and hydrophobic properties is _______.

Nucleotides are composed of

There are several hypotheses considered for the pathway to life. The "replicator first" hypothesis has several problems including

Which of the following is not a nucleotide?

All of the following bases are found in DNA except

What is the evidence supporting the claim that ancient rocks contain the fossils of cells?

Studying Life

Small Molecules and the Chemistry of Life

Proteins, Carbohydrates, and Lipids

Cells: the Working Units of Life

Cell Membranes

Cell Signaling and Communication

Energy, Enzymes, and Metabolism

Pathways That Harvest Chemical Energy

Photosynthesis: Energy From Sunlight

The Cell Cycle and Cell Division

Inheritance, Genes, and Chromosomes

Dna and Its Role in Heredity

From Dna to Protein: Gene Expression

Gene Mutation and Molecular Medicine

Regulation of Gene Expression

Genomes

Recombinent Dna and Biotechnology

Differential Gene Expression in Development

Development and Evolutionary Change

Evidence and Mechanisms of Evolution

Reconstructing and Using Phylogenies

Species and Their Formation

Evolution of Genes and Genomes

The History of Life on Earth

Bacteria and Archaea: the Prokaryotic Domains

The Origin and Diversification of Eukaryotes

Plants Without Seeds: From Water to Land

The Evolution of Seed Plants

Fungi: Recyclers, Pathogens, Parasites, and Plant Partners

Animal Origins and the Evolution of Body Plans

Protostome Animals

Deuterostome Animals

The Plant Body

Transport in Plants

Plant Nutrition

Regulation of Plant Growth

Reproduction in Flowering Plants

Plant Responses to Environmental Challenges

Physiology, Homeostasis, and Temperature Regulation

Animal Hormones

Immunology: Animal Defense Systems

Animal Reproduction

Animal Development

Neurons and Nervous Systems

Sensory Systems

The Mammalian Nervous System: Structure and Higher Function

Musculoskeletal Systems

Gas Exchange in Animals

Circulatory Systems

Nutrition, Digestion, and Absorption

Salt and Water Balance and Nitrogen

Animal Behavior

Ecology and the Distribution of Life

Population Ecology

Species Interaction and Coevolution

Community Ecology

Ecosystems and Global Ecology

Conservation Biology

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