Question 1

The genetic code is essentially the same for all organisms. From this, one can logically assume all of the following except

Accepted Answer

A) a gene from an organism could theoretically be expressed by any other organism. 
B) all organisms have a common ancestor. 
C) DNA was the first genetic material. 
D) the same codons in different organisms usually translate into the same amino acids. 
E) different organisms have the same number of different types of amino acids. 
A) a gene from an organism could theoretically be expressed by any other organism. 
B) all organisms have a common ancestor. 
C) DNA was the first genetic material. 
D) the same codons in different organisms usually translate into the same amino acids. 
E) different organisms have the same number of different types of amino acids.

Question 2

In which of the following actions does RNA polymerase differ from DNA polymerase?

Accepted Answer

A) RNA polymerase uses RNA as a template, and DNA polymerase uses a DNA template. 
B) RNA polymerase binds to single-stranded DNA, and DNA polymerase binds to double-stranded DNA. 
C) RNA polymerase is much more accurate than DNA polymerase. 
D) RNA polymerase can initiate RNA synthesis, but DNA polymerase requires a primer to initiate DNA synthesis. 
E) RNA polymerase does not need to separate the two strands of DNA in order to synthesize an RNA copy, whereas DNA polymerase must unwind the double helix before it can replicate the DNA. 
A) RNA polymerase uses RNA as a template, and DNA polymerase uses a DNA template. 
B) RNA polymerase binds to single-stranded DNA, and DNA polymerase binds to double-stranded DNA. 
C) RNA polymerase is much more accurate than DNA polymerase. 
D) RNA polymerase can initiate RNA synthesis, but DNA polymerase requires a primer to initiate DNA synthesis. 
E) RNA polymerase does not need to separate the two strands of DNA in order to synthesize an RNA copy, whereas DNA polymerase must unwind the double helix before it can replicate the DNA.

Question 3

The following questions refer to Figure 17.2, a table of codons.

-What amino acid sequence will be generated, based on the following mRNA codon sequence?
5' AUG-UCU-UCG-UUA-UCC-UUG 3'

Accepted Answer

A) met-arg-glu-arg-glu-arg 
B) met-glu-arg-arg-gln-leu 
C) met-ser-leu-ser-leu-ser 
D) met-ser-ser-leu-ser-leu 
E) met-leu-phe-arg-glu-glu 
A) met-arg-glu-arg-glu-arg 
B) met-glu-arg-arg-gln-leu 
C) met-ser-leu-ser-leu-ser 
D) met-ser-ser-leu-ser-leu 
E) met-leu-phe-arg-glu-glu

Question 4

What is the most abundant type of RNA?

Accepted Answer

A) mRNA 
B) tRNA 
C) rRNA 
D) pre-mRNA 
E) hnRNA 
A) mRNA 
B) tRNA 
C) rRNA 
D) pre-mRNA 
E) hnRNA

Question 5

What type of bonding is responsible for maintaining the shape of the tRNA molecule?

Accepted Answer

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

Question 6

During splicing, which molecular component of the spliceosome catalyzes the excision reaction?

Accepted Answer

A) protein 
B) DNA 
C) RNA 
D) lipid 
E) sugar 
A) protein 
B) DNA 
C) RNA 
D) lipid 
E) sugar

Question 7

There are 61 mRNA codons that specify an amino acid, but only 45 tRNAs. This is best explained by the fact that

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 for all 61 tRNAs but some are then destroyed. 
E) competitive exclusion forces some tRNAs to be destroyed by nucleases. 
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 for all 61 tRNAs but some are then destroyed. 
E) competitive exclusion forces some tRNAs to be destroyed by nucleases.

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

Which of the following is True for both prokaryotic and eukaryotic gene expression?

Accepted Answer

A) After transcription, a 3' poly-A tail and a 5' cap are added to mRNA. 
B) Translation of mRNA can begin before transcription is complete. 
C) RNA polymerase binds to the promoter region to begin transcription. 
D) mRNA is synthesized in the 3' → 5' direction. 
E) The mRNA transcript is the exact complement of the gene from which it was copied. 
A) After transcription, a 3' poly-A tail and a 5' cap are added to mRNA. 
B) Translation of mRNA can begin before transcription is complete. 
C) RNA polymerase binds to the promoter region to begin transcription. 
D) mRNA is synthesized in the 3' → 5' direction. 
E) The mRNA transcript is the exact complement of the gene from which it was copied.

Question 10

The following questions refer to Figure 17.5, a table of codons.
   
Figure 17.5
-Using Figure 17.5, 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'-UUUGGGAAA-3' 
B) 5'-GAACCCCTT-3' 
C) 5'-AAAACCTTT-3' 
D) 5'-CTTCGGGAA-3' 
E) 5'-AAACCCUUU-3' 
A) 5'-UUUGGGAAA-3' 
B) 5'-GAACCCCTT-3' 
C) 5'-AAAACCTTT-3' 
D) 5'-CTTCGGGAA-3' 
E) 5'-AAACCCUUU-3'

Question 11

Choose the answer that has these events of protein synthesis in the proper sequence. 1. An aminoacyl-tRNA binds to the A site.
2) A peptide bond forms between the new amino acid and a polypeptide chain.
3) tRNA leaves the P site, and the P site remains vacant.
4) A small ribosomal subunit binds with mRNA.
5) tRNA translocates to the P site.

Accepted Answer

A) 1, 3, 2, 4, 5 
B) 4, 1, 2, 5, 3 
C) 5, 4, 3, 2, 1 
D) 4, 1, 3, 2, 5 
E) 2, 4, 5, 1, 3 
A) 1, 3, 2, 4, 5 
B) 4, 1, 2, 5, 3 
C) 5, 4, 3, 2, 1 
D) 4, 1, 3, 2, 5 
E) 2, 4, 5, 1, 3

Question 12

Accuracy in the translation of mRNA into the primary structure of a polypeptide depends on specificity in the

Accepted Answer

A) binding of ribosomes to mRNA. 
B) shape of the A and P sites of ribosomes. 
C) bonding of the anticodon to the codon. 
D) attachment of amino acids to tRNAs. 
E) both C and D 
A) binding of ribosomes to mRNA. 
B) shape of the A and P sites of ribosomes. 
C) bonding of the anticodon to the codon. 
D) attachment of amino acids to tRNAs. 
E) both C and D

Question 13

Use the following information to answer the following 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.
-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 14

Use the following information to answer the following 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.
-When the ribosome reaches a stop codon on the mRNA, no corresponding tRNA enters the A site. If the translation reaction were to be experimentally stopped at this point, which of the following would you be able to isolate?

Accepted Answer

A) an assembled ribosome with a polypeptide attached to the tRNA in the P site 
B) separated ribosomal subunits, a polypeptide, and free tRNA 
C) an assembled ribosome with a separated polypeptide 
D) separated ribosomal subunits with a polypeptide attached to the tRNA 
E) a cell with fewer ribosomes 
A) an assembled ribosome with a polypeptide attached to the tRNA in the P site 
B) separated ribosomal subunits, a polypeptide, and free tRNA 
C) an assembled ribosome with a separated polypeptide 
D) separated ribosomal subunits with a polypeptide attached to the tRNA 
E) a cell with fewer ribosomes

Question 15

Which of the following is a function of a signal peptide?

Accepted Answer

A) to direct an mRNA molecule into the cisternal space of the ER 
B) to bind RNA polymerase to DNA and initiate transcription 
C) to terminate translation of the messenger RNA 
D) to translocate polypeptides across the ER membrane 
E) to signal the initiation of transcription 
A) to direct an mRNA molecule into the cisternal space of the ER 
B) to bind RNA polymerase to DNA and initiate transcription 
C) to terminate translation of the messenger RNA 
D) to translocate polypeptides across the ER membrane 
E) to signal the initiation of transcription

Question 16

Which of the following DNA mutations is the most likely to be damaging to the protein it specifies?

Accepted Answer

A) a base-pair deletion 
B) a codon substitution 
C) a substitution in the last base of a codon 
D) a codon deletion 
E) a point mutation 
A) a base-pair deletion 
B) a codon substitution 
C) a substitution in the last base of a codon 
D) a codon deletion 
E) a point mutation

Question 17

When translating secretory or membrane proteins, ribosomes are directed to the ER membrane by

Accepted Answer

A) a specific characteristic of the ribosome itself, which distinguishes free ribosomes from bound ribosomes. 
B) a signal-recognition particle that brings ribosomes to a receptor protein in the ER membrane. 
C) moving through a specialized channel of the nucleus. 
D) a chemical signal given off by the ER. 
E) a signal sequence of RNA that precedes the start codon of the message. 
A) a specific characteristic of the ribosome itself, which distinguishes free ribosomes from bound ribosomes. 
B) a signal-recognition particle that brings ribosomes to a receptor protein in the ER membrane. 
C) moving through a specialized channel of the nucleus. 
D) a chemical signal given off by the ER. 
E) a signal sequence of RNA that precedes the start codon of the message.

Question 18

What is the effect of a nonsense mutation in a gene?

Accepted Answer

A) It changes an amino acid in the encoded protein. 
B) It has no effect on the amino acid sequence of the encoded protein. 
C) It introduces a premature stop codon into the mRNA. 
D) It alters the reading frame of the mRNA. 
E) It prevents introns from being excised. 
A) It changes an amino acid in the encoded protein. 
B) It has no effect on the amino acid sequence of the encoded protein. 
C) It introduces a premature stop codon into the mRNA. 
D) It alters the reading frame of the mRNA. 
E) It prevents introns from being excised.

Question 19

Use the following information to answer the following 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 20

Garrod hypothesized that "inborn errors of metabolism" such as alkaptonuria occur because

Accepted Answer

A) genes dictate the production of specific enzymes, and affected individuals have genetic defects that cause them to lack certain enzymes. 
B) enzymes are made of DNA, and affected individuals lack DNA polymerase. 
C) many metabolic enzymes use DNA as a cofactor, and affected individuals have mutations that prevent their enzymes from interacting efficiently with DNA. 
D) certain metabolic reactions are carried out by ribozymes, and affected individuals lack key splicing factors. 
E) metabolic enzymes require vitamin cofactors, and affected individuals have significant nutritional deficiencies. 
A) genes dictate the production of specific enzymes, and affected individuals have genetic defects that cause them to lack certain enzymes. 
B) enzymes are made of DNA, and affected individuals lack DNA polymerase. 
C) many metabolic enzymes use DNA as a cofactor, and affected individuals have mutations that prevent their enzymes from interacting efficiently with DNA. 
D) certain metabolic reactions are carried out by ribozymes, and affected individuals lack key splicing factors. 
E) metabolic enzymes require vitamin cofactors, and affected individuals have significant nutritional deficiencies.

Exam 17: From Gene to Protein

The genetic code is essentially the same for all organisms. From this, one can logically assume all of the following except

In which of the following actions does RNA polymerase differ from DNA polymerase?

The following questions refer to Figure 17.2, a table of codons. -What amino acid sequence will be generated, based on the following mRNA codon sequence? 5' AUG-UCU-UCG-UUA-UCC-UUG 3'

What is the most abundant type of RNA?

What type of bonding is responsible for maintaining the shape of the tRNA molecule?

During splicing, which molecular component of the spliceosome catalyzes the excision reaction?

There are 61 mRNA codons that specify an amino acid, but only 45 tRNAs. This is best explained by the fact that

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

Which of the following is True for both prokaryotic and eukaryotic gene expression?

The following questions refer to Figure 17.5, a table of codons. Figure 17.5 -Using Figure 17.5, identify a 5' → 3' sequence of nucleotides in the DNA template strand for an mRNA coding for the polypeptide sequence Phe-Pro-Lys.

Accuracy in the translation of mRNA into the primary structure of a polypeptide depends on specificity in the

Which of the following is a function of a signal peptide?

Which of the following DNA mutations is the most likely to be damaging to the protein it specifies?

When translating secretory or membrane proteins, ribosomes are directed to the ER membrane by

What is the effect of a nonsense mutation in a gene?

Garrod hypothesized that "inborn errors of metabolism" such as alkaptonuria occur because

Introduction: Themes in the Study of Life

The Chemical Context of Life

Water and the Fitness of the Environment

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: Harvesting Chemical Energy

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

Control 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 Introduction to Animal Diversity

Invertebrates

Vertebrates

Plant Structure, Growth, and Development

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

Conservation Biology and Restoration Ecology

Filters