Question 1

Which of the following mutations would be most likely to have a harmful effect on an organism?

Accepted Answer

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

Question 2

Which of the following statements best supports the one gene-one enzyme hypothesis?

Accepted Answer

A)  A mutation in a single gene can result in a defective protein. 
B)  Alkaptonuria results when individuals lack multiple enzymes involved in the catalysis of homogentisic acid. 
C)  Sickle-cell anemia results in normal hemoglobin. 
D)  Multiple antibody genes can code for different related proteins, depending on the splicing that takes place post-transcriptionally. 
A)  A mutation in a single gene can result in a defective protein. 
B)  Alkaptonuria results when individuals lack multiple enzymes involved in the catalysis of homogentisic acid. 
C)  Sickle-cell anemia results in normal hemoglobin. 
D)  Multiple antibody genes can code for different related proteins, depending on the splicing that takes place post-transcriptionally.

Question 3

Use the figure to answer the question.   What type of bonding is responsible for maintaining the shape of the tRNA molecule shown in the figure?

Accepted Answer

A)  ionic bonding between phosphates 
B)  hydrogen bonding between base pairs 
C)  van der Waals interactions between hydrogen atoms 
D)  peptide bonding between amino acids 
A)  ionic bonding between phosphates 
B)  hydrogen bonding between base pairs 
C)  van der Waals interactions between hydrogen atoms 
D)  peptide bonding between amino acids

Question 4

Which of the following statements correctly describes a ribozyme?

Accepted Answer

A)  It is a catalyst that uses RNA as a substrate. 
B)  It is an RNA with catalytic activity. 
C)  It is an enzyme that catalyzes the association between the large and small ribosomal subunits. 
D)  It is an enzyme that synthesizes RNA as part of the transcription process. 
A)  It is a catalyst that uses RNA as a substrate. 
B)  It is an RNA with catalytic activity. 
C)  It is an enzyme that catalyzes the association between the large and small ribosomal subunits. 
D)  It is an enzyme that synthesizes RNA as part of the transcription process.

Question 5

The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following statements to be true?

Accepted Answer

A)  A gene from an organism can theoretically be expressed by any other organism. 
B)  DNA was the first genetic material. 
C)  The same codons in different organisms translate into different amino acids. 
D)  Different organisms have different types of amino acids. 
A)  A gene from an organism can theoretically be expressed by any other organism. 
B)  DNA was the first genetic material. 
C)  The same codons in different organisms translate into different amino acids. 
D)  Different organisms have different types of amino acids.

Question 6

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 
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

Question 7

What is the function of the release factor during translation in eukaryotes?

Accepted Answer

A)  It binds to the stop codon in the A site in place of a tRNA. 
B)  It releases the amino acid from its tRNA to allow the amino acid to form a peptide bond. 
C)  It supplies a source of energy for termination of translation. 
D)  It releases the ribosome from the ER to allow polypeptides into the cytosol. 
A)  It binds to the stop codon in the A site in place of a tRNA. 
B)  It releases the amino acid from its tRNA to allow the amino acid to form a peptide bond. 
C)  It supplies a source of energy for termination of translation. 
D)  It releases the ribosome from the ER to allow polypeptides into the cytosol.

Question 8

RNA is single stranded, can hydrogen-bond with other nucleic acids, and has functional groups that can function in catalysis. These characteristics support that RNA could have which of the following cellular roles?

Accepted Answer

A)  tagging proteins for degradation by lysosomes 
B)  targeting proteins for secretion 
C)  forming scaffolds for ribosome attachment 
D)  forming peptide bonds 
A)  tagging proteins for degradation by lysosomes 
B)  targeting proteins for secretion 
C)  forming scaffolds for ribosome attachment 
D)  forming peptide bonds

Question 9

Which of the following molecular structures contains codons?

Accepted Answer

A)  a protein 
B)  mRNA 
C)  tRNA 
D)  rRNA 
A)  a protein 
B)  mRNA 
C)  tRNA 
D)  rRNA

Question 10

Use the figure to answer the question.   Refer to the metabolic pathway illustrated. If I, II, III and IV are all required for growth, a bacterial strain that does not make enzyme Y would be able to grow on medium supplemented with which of the following compounds?

Accepted Answer

A)  nutrient A only 
B)  nutrient C only 
C)  nutrients A and C only 
D)  nutrients B and D only 
A)  nutrient A only 
B)  nutrient C only 
C)  nutrients A and C only 
D)  nutrients B and D only

Question 11

An mRNA molecule with the sequence 5′-CCG-ACG-3′is being translated at a ribosome. The following charged transfer RNA molecules (with their anticodons shown in the 3′ to 5′ direction) are available. Two of them can correctly match the mRNA so that a dipeptide can form.
   Which of the following dipeptides will form from this mRNA?

Accepted Answer

A)  cysteine-alanine 
B)  proline-threonine 
C)  glycine-cysteine 
D)  alanine-alanine
Answer: B
Topic: Translation is the RNA-directed synthesis of a polypeptide: A Closer Look
Bloom's Taxonomy: Levels 3-4: Applying/Analyzing
Learning Outcome: 17.4, Global LO: G2, V&C LO: VC-I
-An mRNA molecule with the sequence 5′-CCG-ACG-3′is being read by a ribosome.
During translation which of the following tRNA anticodons will be the first to productively bind with this mRNA? 
A)  3′-GGC-5′ 
B)  5′-GGC-3′ 
C)  5′-UGC-3′ 
D)  3′-UGC-5′ 
A)  cysteine-alanine 
B)  proline-threonine 
C)  glycine-cysteine 
D)  alanine-alanine
Answer: B
Topic: Translation is the RNA-directed synthesis of a polypeptide: A Closer Look
Bloom's Taxonomy: Levels 3-4: Applying/Analyzing
Learning Outcome: 17.4, Global LO: G2, V&C LO: VC-I
-An mRNA molecule with the sequence 5′-CCG-ACG-3′is being read by a ribosome.
During translation which of the following tRNA anticodons will be the first to productively bind with this mRNA? 
A)  3′-GGC-5′ 
B)  5′-GGC-3′ 
C)  5′-UGC-3′ 
D)  3′-UGC-5′

Question 12

If a bacteria contained a mutant aminoacyl-tRNA synthetase that attaches a lysine instead of the normal phenylalanine to tRNAs with the anticodon AAA which of the following would occur?

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. 
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.

Question 13

Which of the following processes correctly describes alternative RNA splicing?

Accepted Answer

A)  It is a mechanism for increasing the rate of translation. 
B)  It can allow the production of proteins of different sizes and functions from a single mRNA. 
C)  It can allow the production of similar proteins from different RNAs. 
D)  It increases the rate of transcription. 
A)  It is a mechanism for increasing the rate of translation. 
B)  It can allow the production of proteins of different sizes and functions from a single mRNA. 
C)  It can allow the production of similar proteins from different RNAs. 
D)  It increases the rate of transcription.

Question 14

Which of the following structures is needed for the translation initiation complex to form in eukaryotes?

Accepted Answer

A)  promoter 
B)  exon 
C)  5′ cap 
D)  5′ AUG 3′ 
A)  promoter 
B)  exon 
C)  5′ cap 
D)  5′ AUG 3′

Question 15

Which of the following best explains the observation that in bacteria, there are 61 mRNA codons that specify an amino acid, but only 45 tRNAs?

Accepted Answer

A)  Some tRNAs have anticodons that recognize four or more different codons. 
B)  The rules for base pairing between the third base of a codon and tRNA are flexible. 
C)  Many codons are never used, so the tRNAs that recognize them are dispensable. 
D)  The DNA codes 61 tRNAs, but some are destroyed after transcription. 
A)  Some tRNAs have anticodons that recognize four or more different codons. 
B)  The rules for base pairing between the third base of a codon and tRNA are flexible. 
C)  Many codons are never used, so the tRNAs that recognize them are dispensable. 
D)  The DNA codes 61 tRNAs, but some are destroyed after transcription.

Question 16

Post-translational modifications of proteins may include which of the following processes?

Accepted Answer

A)  removal of introns 
B)  addition of a 5′ cap 
C)  synthesis of peptide bonds 
D)  addition of carbohydrates to form a glycoprotein 
A)  removal of introns 
B)  addition of a 5′ cap 
C)  synthesis of peptide bonds 
D)  addition of carbohydrates to form a glycoprotein

Question 17

Which answer correctly compares the primary transcript in the nucleus of a eukaryotic cell with the functional mRNA?

Accepted Answer

A)  the primary transcript is the same size as the mRNA 
B)  the primary transcript is larger than the mRNA 
C)  the primary transcript is smaller than the mRNA 
D)  both the primary transcript and mRNA contain introns 
A)  the primary transcript is the same size as the mRNA 
B)  the primary transcript is larger than the mRNA 
C)  the primary transcript is smaller than the mRNA 
D)  both the primary transcript and mRNA contain introns

Question 18

Using the figure identify a 5'→ 3' sequence of nucleotides in the DNA template strand for an mRNA coding for the polypeptide sequence Phe-Pro-Lys.

Accepted Answer

A)  5'-UUUCCCAAA-3' 
B)  5'-GAACCCCTT-3' 
C)  5'-CTTCGGGAA-3' 
D)  5'-AAACCCUUU-3' 
A)  5'-UUUCCCAAA-3' 
B)  5'-GAACCCCTT-3' 
C)  5'-CTTCGGGAA-3' 
D)  5'-AAACCCUUU-3'

Question 19

Jennifer Doudna discovered CRISPR-Cas9 due to its role in which of the following?

Accepted Answer

A)  defending bacteria against bacteriophage infection 
B)  strengthening a virus' ability to infect its host 
C)  protecting mammalian cells against DNA virus integration 
D)  promoting adaptation by generating random mutations 
A)  defending bacteria against bacteriophage infection 
B)  strengthening a virus' ability to infect its host 
C)  protecting mammalian cells against DNA virus integration 
D)  promoting adaptation by generating random mutations

Question 20

The most commonly occurring mutation in people with cystic fibrosis is a deletion of a single codon. What is the result of this type of mutation?

Accepted Answer

A)  a base-pair substitution 
B)  a frameshift mutation 
C)  a polypeptide missing an amino acid 
D)  a polypeptide missing its N-terminus 
A)  a base-pair substitution 
B)  a frameshift mutation 
C)  a polypeptide missing an amino acid 
D)  a polypeptide missing its N-terminus

Exam 17: Expression of Genes

Which of the following mutations would be most likely to have a harmful effect on an organism?

Which of the following statements best supports the one gene-one enzyme hypothesis?

Use the figure to answer the question. What type of bonding is responsible for maintaining the shape of the tRNA molecule shown in the figure?

Which of the following statements correctly describes a ribozyme?

The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following statements to be true?

In eukaryotic cells, transcription cannot begin until ________.

What is the function of the release factor during translation in eukaryotes?

RNA is single stranded, can hydrogen-bond with other nucleic acids, and has functional groups that can function in catalysis. These characteristics support that RNA could have which of the following cellular roles?

Which of the following molecular structures contains codons?

Use the figure to answer the question. Refer to the metabolic pathway illustrated. If I, II, III and IV are all required for growth, a bacterial strain that does not make enzyme Y would be able to grow on medium supplemented with which of the following compounds?

If a bacteria contained a mutant aminoacyl-tRNA synthetase that attaches a lysine instead of the normal phenylalanine to tRNAs with the anticodon AAA which of the following would occur?

Which of the following processes correctly describes alternative RNA splicing?

Which of the following structures is needed for the translation initiation complex to form in eukaryotes?

Which of the following best explains the observation that in bacteria, there are 61 mRNA codons that specify an amino acid, but only 45 tRNAs?

Post-translational modifications of proteins may include which of the following processes?

Which answer correctly compares the primary transcript in the nucleus of a eukaryotic cell with the functional mRNA?

Using the figure identify a 5'→ 3' sequence of nucleotides in the DNA template strand for an mRNA coding for the polypeptide sequence Phe-Pro-Lys.

Jennifer Doudna discovered CRISPR-Cas9 due to its role in which of the following?

The most commonly occurring mutation in people with cystic fibrosis is a deletion of a single codon. What is the result of this type of mutation?

Biology and Its Themes

Atoms and Molecules

The Chemistry of Water

Carbon: the Basis of Molecular Diversity

Biological Macromolecules and Lipids

Energy and Life

Cell Structure and Function

Cell Membranes

Cellular Signaling

Cell Respiration

Photosynthetic Processes

Mitosis

Sexual Life Cycles and Meiosis

Mendelian Genetics

Linkage and Chromosomes

Nucleic Acids and Inheritance

Control of Gene Expression

Dna Technology

The Evolution of Genomes

How Evolution Works

Phylogenetic Reconstruction

Microevolution

Species and Speciation

Macroevolution

Introduction to Viruses

Prokaryotes

The Origin and Evolution of Eukaryotes

Nonvascular and Seedless Vascular Plants

Seed Plants

Introduction to Fungi

An Introduction to Animal Diversity

Invertebrates

Vertebrates

Plant Structure and Growth

Transport in Vascular Plants

Plant Nutrition

Reproduction of Flowering Plants

Plant Signals and Behavior

The Animal Body

Chemical Signals in Animals

Animal Digestive Systems

Animal Transport Systems

Animal Excretory Systems

Animal Reproductive Systems

Development in Animals

Animal Defenses Against Infection

Electrical Signals in Animals

Neural Regulation in Animals

Sensation and Movement in Animals

An Overview of Ecology

Behavioral Ecology

Populations and Life History Traits

Biodiversity and Communities

Energy Flow and Chemical Cycling in Ecosystems

Conservation and Global Ecology

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