Question 1

Which of the following is true of transcription in domain Archaea?

Accepted Answer

A)  It is regulated in the same way as in domain Bacteria. 
B)  There is only one kind of RNA polymerase. 
C)  It is roughly simultaneous with translation. 
D)  Promoters are identical to those in domain Eukarya. 
E)  It terminates in a manner similar to bacteria. 
A)  It is regulated in the same way as in domain Bacteria. 
B)  There is only one kind of RNA polymerase. 
C)  It is roughly simultaneous with translation. 
D)  Promoters are identical to those in domain Eukarya. 
E)  It terminates in a manner similar to bacteria.

Question 2

Use the following information to answer the next few questions.
The enzyme polynucleotide phosphorylase randomly assembles nucleotides into a polynucleotide polymer.
-You add polynucleotide phosphorylase to a solution of ATP, GTP, and UTP. How many artificial mRNA 3 nucleotide codons would be possible?

Accepted Answer

A)  3 
B)  6 
C)  9 
D)  27 
E)  81 
A)  3 
B)  6 
C)  9 
D)  27 
E)  81

Question 3

Use the following information to answer the next few questions.
A transfer RNA (#1) attached to the amino acid lysine enters the ribosome. The lysine binds to the growing polypeptide on the other tRNA (#2) in the ribosome already.
-Which of the following mutations would be most likely to have a harmful effect on an organism?

Accepted Answer

A)  a nucleotide-pair substitution 
B)  a deletion of three nucleotides near the middle of a gene 
C)  a single nucleotide deletion in the middle of an intron 
D)  a single nucleotide deletion near the end of the coding sequence 
E)  a single nucleotide insertion downstream of, and close to, the start of the coding sequence 
A)  a nucleotide-pair substitution 
B)  a deletion of three nucleotides near the middle of a gene 
C)  a single nucleotide deletion in the middle of an intron 
D)  a single nucleotide deletion near the end of the coding sequence 
E)  a single nucleotide insertion downstream of, and close to, the start of the coding sequence

Question 4

An experimenter has altered the 3' end of the tRNA corresponding to the amino acid methionine in such a way as to remove the 3' AC. Which of the following hypotheses describes the most likely result?

Accepted Answer

A)  tRNA will not form a cloverleaf. 
B)  The nearby stem end will pair improperly. 
C)  The amino acid methionine will not bind. 
D)  The anticodon will not bind with the mRNA codon. 
E)  The aminoacylsynthetase will not be formed. 
A)  tRNA will not form a cloverleaf. 
B)  The nearby stem end will pair improperly. 
C)  The amino acid methionine will not bind. 
D)  The anticodon will not bind with the mRNA codon. 
E)  The aminoacylsynthetase will not be formed.

Question 5

The following question refers to this figure of a simple metabolic pathway:
  
-According to Beadle and Tatum's hypothesis, how many genes are necessary for this pathway?

Accepted Answer

A)  0 
B)  1 
C)  2 
D)  3 
E)  It cannot be determined from the pathway. 
A)  0 
B)  1 
C)  2 
D)  3 
E)  It cannot be determined from the pathway.

Question 6

Suppose that a mutation alters the formation of a tRNA such that it still attaches to the same amino acid (phe)but its anticodon loop has the sequence AAU that binds to the mRNA codon UUA (that usually specifies leucine leu).

Accepted Answer

A)  The modified tRNA will cause this mRNA to make only nonfunctioning product. 
B)  The tRNA-leu will not be able to enter the site of the ribosome to bind to the UUA. 
C)  One mutated tRNA molecule will be relatively inconsequential because it will compete with many "normal" ones. 
D)  The tRNA will be so unstable that it will not participate in translation. 
E)  The mutated tRNA will result in an amino acid variant in all copies of the protein. 
A)  The modified tRNA will cause this mRNA to make only nonfunctioning product. 
B)  The tRNA-leu will not be able to enter the site of the ribosome to bind to the UUA. 
C)  One mutated tRNA molecule will be relatively inconsequential because it will compete with many "normal" ones. 
D)  The tRNA will be so unstable that it will not participate in translation. 
E)  The mutated tRNA will result in an amino acid variant in all copies of the protein.

Question 7

Use the following information to answer the next few questions.
A transfer RNA (#1) attached to the amino acid lysine enters the ribosome. The lysine binds to the growing polypeptide on the other tRNA (#2) in the ribosome already.
-In eukaryotic cells, transcription cannot begin until

Accepted Answer

A)  the two DNA strands have completely separated and exposed the promoter. 
B)  several transcription factors have bound to the promoter. 
C)  the 5' caps are removed from the mRNA. 
D)  the DNA introns are removed from the template. 
E)  DNA nucleases have isolated the transcription unit. 
A)  the two DNA strands have completely separated and exposed the promoter. 
B)  several transcription factors have bound to the promoter. 
C)  the 5' caps are removed from the mRNA. 
D)  the DNA introns are removed from the template. 
E)  DNA nucleases have isolated the transcription unit.

Question 8

A transcription unit that is 8,000 nucleotides long may use 1,200 nucleotides to make a protein consisting of approximately 400 amino acids. This is best explained by the fact that

Accepted Answer

A)  many noncoding stretches of nucleotides are present in mRNA. 
B)  there is redundancy and ambiguity in the genetic code. 
C)  many nucleotides are needed to code for each amino acid. 
D)  nucleotides break off and are lost during the transcription process. 
E)  there are termination exons near the beginning of mRNA. 
A)  many noncoding stretches of nucleotides are present in mRNA. 
B)  there is redundancy and ambiguity in the genetic code. 
C)  many nucleotides are needed to code for each amino acid. 
D)  nucleotides break off and are lost during the transcription process. 
E)  there are termination exons near the beginning of mRNA.

Question 9

Why might a point mutation in DNA make a difference in the level of protein's activity?

Accepted Answer

A)  It might result in a chromosomal translocation. 
B)  It might exchange one stop codon for another stop codon. 
C)  It might exchange one serine codon for a different serine codon. 
D)  It might substitute an amino acid in the active site. 
E)  It might substitute the N-terminus of the polypeptide for the C-terminus. 
A)  It might result in a chromosomal translocation. 
B)  It might exchange one stop codon for another stop codon. 
C)  It might exchange one serine codon for a different serine codon. 
D)  It might substitute an amino acid in the active site. 
E)  It might substitute the N-terminus of the polypeptide for the C-terminus.

Question 10

Use the following information to answer the next few questions.
A transfer RNA (#1) attached to the amino acid lysine enters the ribosome. The lysine binds to the growing polypeptide on the other tRNA (#2) in the ribosome already.
-Which component of the complex described enters the exit tunnel through the large subunit of the ribosome?

Accepted Answer

A)  tRNA with attached lysine (#1) 
B)  tRNA with polypeptide (#2) 
C)  tRNA that no longer has attached amino acid 
D)  newly formed polypeptide 
E)  initiation and elongation factors 
A)  tRNA with attached lysine (#1) 
B)  tRNA with polypeptide (#2) 
C)  tRNA that no longer has attached amino acid 
D)  newly formed polypeptide 
E)  initiation and elongation factors

Question 11

Use the following information to answer the next few questions.
A transfer RNA (#1) attached to the amino acid lysine enters the ribosome. The lysine binds to the growing polypeptide on the other tRNA (#2) in the ribosome already.
-Where does tRNA #2 move to after this bonding of lysine to the polypeptide?

Accepted Answer

A)  A site 
B)  P site 
C)  E site 
D)  exit tunnel 
E)  directly to the cytosol 
A)  A site 
B)  P site 
C)  E site 
D)  exit tunnel 
E)  directly to the cytosol

Question 12

The TATA sequence is found only several nucleotides away from the start site of transcription. This most probably relates to which of the following?

Accepted Answer

A)  the number of hydrogen bonds between A and T in DNA 
B)  the triplet nature of the codon 
C)  the ability of this sequence to bind to the start site 
D)  the supercoiling of the DNA near the start site 
E)  the 3-D shape of a DNA molecule 
A)  the number of hydrogen bonds between A and T in DNA 
B)  the triplet nature of the codon 
C)  the ability of this sequence to bind to the start site 
D)  the supercoiling of the DNA near the start site 
E)  the 3-D shape of a DNA molecule

Question 13

The following question refers to this figure of a simple metabolic pathway:
  
-If A, B, and C are all required for growth, a strain mutant for the gene-encoding enzyme B would be capable of growing on which of the following media?

Accepted Answer

A)  minimal medium 
B)  minimal medium supplemented with A only 
C)  minimal medium supplemented with B only 
D)  minimal medium supplemented with C only 
E)  minimal medium supplemented with nutrients A and B 
A)  minimal medium 
B)  minimal medium supplemented with A only 
C)  minimal medium supplemented with B only 
D)  minimal medium supplemented with C only 
E)  minimal medium supplemented with nutrients A and B

Question 14

Which of the following variations on translation would be most disadvantageous for a cell?

Accepted Answer

A)  translating polypeptides directly from DNA 
B)  using fewer kinds of tRNA 
C)  having only one stop codon 
D)  lengthening the half-life of mRNA 
E)  having a second codon (besides AUG) as a start codon 
A)  translating polypeptides directly from DNA 
B)  using fewer kinds of tRNA 
C)  having only one stop codon 
D)  lengthening the half-life of mRNA 
E)  having a second codon (besides AUG) as a start codon

Question 15

Which of the following statements best describes the termination of transcription in prokaryotes?

Accepted Answer

A)  RNA polymerase transcribes through the polyadenylation signal, causing proteins to associate with the transcript and cut it free from the polymerase. 
B)  RNA polymerase transcribes through the terminator sequence, causing the polymerase to separate from the DNA and release the transcript. 
C)  RNA polymerase transcribes through an intron, and the snRNPs cause the polymerase to let go of the transcript. 
D)  Once transcription has initiated, RNA polymerase transcribes until it reaches the end of the chromosome. 
E)  RNA polymerase transcribes through a stop codon, causing the polymerase to stop advancing through the gene and release the mRNA. 
A)  RNA polymerase transcribes through the polyadenylation signal, causing proteins to associate with the transcript and cut it free from the polymerase. 
B)  RNA polymerase transcribes through the terminator sequence, causing the polymerase to separate from the DNA and release the transcript. 
C)  RNA polymerase transcribes through an intron, and the snRNPs cause the polymerase to let go of the transcript. 
D)  Once transcription has initiated, RNA polymerase transcribes until it reaches the end of the chromosome. 
E)  RNA polymerase transcribes through a stop codon, causing the polymerase to stop advancing through the gene and release the mRNA.

Question 16

Which of the following does not occur in prokaryotic eukaryotic gene expression, but does in eukaryotic gene expression?

Accepted Answer

A)  mRNA, tRNA, and rRNA are transcribed. 
B)  RNA polymerase binds to the promoter. 
C)  A poly-A tail is added to the 3' end of an mRNA and a cap is added to the 5' end. 
D)  Transcription can begin as soon as translation has begun even a little. 
E)  RNA polymerase requires a primer to elongate the molecule. 
A)  mRNA, tRNA, and rRNA are transcribed. 
B)  RNA polymerase binds to the promoter. 
C)  A poly-A tail is added to the 3' end of an mRNA and a cap is added to the 5' end. 
D)  Transcription can begin as soon as translation has begun even a little. 
E)  RNA polymerase requires a primer to elongate the molecule.

Question 17

Which of the following statements is true about protein synthesis in prokaryotes?

Accepted Answer

A)  Extensive RNA processing is required before prokaryotic transcripts can be translated. 
B)  Translation can begin while transcription is still in progress. 
C)  Prokaryotic cells have complicated mechanisms for targeting proteins to the appropriate cellular organelles. 
D)  Translation requires antibiotic activity. 
E)  Unlike eukaryotes, prokaryotes require no initiation or elongation factors. 
A)  Extensive RNA processing is required before prokaryotic transcripts can be translated. 
B)  Translation can begin while transcription is still in progress. 
C)  Prokaryotic cells have complicated mechanisms for targeting proteins to the appropriate cellular organelles. 
D)  Translation requires antibiotic activity. 
E)  Unlike eukaryotes, prokaryotes require no initiation or elongation factors.

Question 18

A mutant bacterial cell has a defective aminoacyl synthetase that attaches a lysine to tRNAs with the anticodon AAA instead of the normal phenylalanine. The consequence of this for the cell will be that

Accepted Answer

A)  none of the proteins in the cell will contain phenylalanine. 
B)  proteins in the cell will include lysine instead of phenylalanine at amino acid positions specified by the codon UUU. 
C)  the cell will compensate for the defect by attaching phenylalanine to tRNAs with lysine-specifying anticodons. 
D)  the ribosome will skip a codon every time a UUU is encountered. 
E)  none of the options will occur; the cell will recognize the error and destroy the tRNA. 
A)  none of the proteins in the cell will contain phenylalanine. 
B)  proteins in the cell will include lysine instead of phenylalanine at amino acid positions specified by the codon UUU. 
C)  the cell will compensate for the defect by attaching phenylalanine to tRNAs with lysine-specifying anticodons. 
D)  the ribosome will skip a codon every time a UUU is encountered. 
E)  none of the options will occur; the cell will recognize the error and destroy the tRNA.

Question 19

A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is

Accepted Answer

A)  TTT. 
B)  UUA. 
C)  UUU. 
D)  AAA. 
E)  either UAA or TAA, depending on first base wobble. 
A)  TTT. 
B)  UUA. 
C)  UUU. 
D)  AAA. 
E)  either UAA or TAA, depending on first base wobble.

Question 20

The following question refers to this figure of a simple metabolic pathway:
  
-If A, B, and C are all required for growth, a strain that is mutant for the gene-encoding enzyme A would be able to grow on which of the following media?

Accepted Answer

A)  minimal medium 
B)  minimal medium supplemented with nutrient A only 
C)  minimal medium supplemented with nutrient B only 
D)  minimal medium supplemented with nutrient C only 
E)  minimal medium supplemented with nutrients A and C 
A)  minimal medium 
B)  minimal medium supplemented with nutrient A only 
C)  minimal medium supplemented with nutrient B only 
D)  minimal medium supplemented with nutrient C only 
E)  minimal medium supplemented with nutrients A and C

Exam 17: From Gene to Protein

Which of the following is true of transcription in domain Archaea?

An experimenter has altered the 3' end of the tRNA corresponding to the amino acid methionine in such a way as to remove the 3' AC. Which of the following hypotheses describes the most likely result?

The following question refers to this figure of a simple metabolic pathway: -According to Beadle and Tatum's hypothesis, how many genes are necessary for this pathway?

Suppose that a mutation alters the formation of a tRNA such that it still attaches to the same amino acid (phe)but its anticodon loop has the sequence AAU that binds to the mRNA codon UUA (that usually specifies leucine leu).

Use the following information to answer the next few questions. A transfer RNA (#1) attached to the amino acid lysine enters the ribosome. The lysine binds to the growing polypeptide on the other tRNA (#2) in the ribosome already. -In eukaryotic cells, transcription cannot begin until

A transcription unit that is 8,000 nucleotides long may use 1,200 nucleotides to make a protein consisting of approximately 400 amino acids. This is best explained by the fact that

Why might a point mutation in DNA make a difference in the level of protein's activity?

The TATA sequence is found only several nucleotides away from the start site of transcription. This most probably relates to which of the following?

The following question refers to this figure of a simple metabolic pathway: -If A, B, and C are all required for growth, a strain mutant for the gene-encoding enzyme B would be capable of growing on which of the following media?

Which of the following variations on translation would be most disadvantageous for a cell?

Which of the following statements best describes the termination of transcription in prokaryotes?

Which of the following does not occur in prokaryotic eukaryotic gene expression, but does in eukaryotic gene expression?

Which of the following statements is true about protein synthesis in prokaryotes?

A mutant bacterial cell has a defective aminoacyl synthetase that attaches a lysine to tRNAs with the anticodon AAA instead of the normal phenylalanine. The consequence of this for the cell will be that

A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is

The following question refers to this figure of a simple metabolic pathway: -If A, B, and C are all required for growth, a strain that is mutant for the gene-encoding enzyme A would be able to grow on which of the following media?

Introduction: Themes in the Study of Life

The Chemical Context of Life

Water and Life

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cell Communication

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

Regulation of Gene Expression

Viruses

Biotechnology

Genomes and Their Evolution

Descent with Modification: A Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity II: The Evolution of Seed Plants

Fungi

An Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Plant Structure, Growth, and Development

Resource Acquisition and Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons, Synapses, and Signaling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behavior

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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