Question 1

Of the following, which is the most current description of a gene?

Accepted Answer

A) a unit of heredity that causes formation of a phenotypic characteristic 
B) a DNA subunit that codes for a single complete protein 
C) a DNA sequence that is expressed to form a functional product: either RNA or polypeptide 
D) a DNA-RNA sequence combination that results in an enzymatic product 
E) a discrete unit of hereditary information that consists of a sequence of amino acids 
A) a unit of heredity that causes formation of a phenotypic characteristic 
B) a DNA subunit that codes for a single complete protein 
C) a DNA sequence that is expressed to form a functional product: either RNA or polypeptide 
D) a DNA-RNA sequence combination that results in an enzymatic product 
E) a discrete unit of hereditary information that consists of a sequence of amino acids

Question 2

The term polyribosome refers to

Accepted Answer

A) a polymerase ribosome complex. 
B) the beaded look of the rough ER. 
C) the ribosome complex in eukaryotes. 
D) the ribosome complex in prokaryotes. 
E) a string of ribosomes attached to a mRNA. 
A) a polymerase ribosome complex. 
B) the beaded look of the rough ER. 
C) the ribosome complex in eukaryotes. 
D) the ribosome complex in prokaryotes. 
E) a string of ribosomes attached to a mRNA.

Question 3

The following questions refer to this table of codons.
  
-A possible sequence of nucleotides in the template strand of DNA that would code for the polypeptide sequence phe-leu-ile-val would be

Accepted Answer

A) 5' TTG-CTA-CAG-TAG 3'. 
B) 3' AAC-GAC-GUC-AUA 5'. 
C) 5' AUG-CTG-CAG-TAT 3'. 
D) 3' AAA-AAT-ATA-ACA 5'. 
E) 3' AAA-GAA-TAA-CAA 5'. 
A) 5' TTG-CTA-CAG-TAG 3'. 
B) 3' AAC-GAC-GUC-AUA 5'. 
C) 5' AUG-CTG-CAG-TAT 3'. 
D) 3' AAA-AAT-ATA-ACA 5'. 
E) 3' AAA-GAA-TAA-CAA 5'.

Question 4

The anticodon of a particular tRNA molecule is

Accepted Answer

A) complementary to the corresponding mRNA codon. 
B) complementary to the corresponding triplet in rRNA. 
C) the part of tRNA that bonds to a specific amino acid. 
D) changeable, depending on the amino acid that attaches to the tRNA. 
E) catalytic, making the tRNA a ribozyme. 
A) complementary to the corresponding mRNA codon. 
B) complementary to the corresponding triplet in rRNA. 
C) the part of tRNA that bonds to a specific amino acid. 
D) changeable, depending on the amino acid that attaches to the tRNA. 
E) catalytic, making the tRNA a ribozyme.

Question 5

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 6

Use the following model of a eukaryotic transcript to answer the next few questions.
5' UTR E₁ I₁ E₂ I₂ E₃ I₃ E₄ UTR 3'
-When the spliceosome binds to elements of this structure, where can it attach?

Accepted Answer

A) to the exons 
B) to the 5' UTR 
C) to the 3' UTR 
D) to an adjacent intron and exon 
E) to the end of an intron 
A) to the exons 
B) to the 5' UTR 
C) to the 3' UTR 
D) to an adjacent intron and exon 
E) to the end of an intron

Question 7

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

Accepted Answer

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

Question 8

What is the role of UV light in this circumstance?

Accepted Answer

A) It is a promoter. 
B) It functions in RNA splicing. 
C) It initiates RNA interference. 
D) It is a mutagen. 
E) It blocks tumour suppression. 
A) It is a promoter. 
B) It functions in RNA splicing. 
C) It initiates RNA interference. 
D) It is a mutagen. 
E) It blocks tumour suppression.

Question 9

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 10

In comparing DNA replication with RNA transcription in the same cell, which of the following is true only of replication?

Accepted Answer

A) It uses RNA polymerase. 
B) It makes a new molecule from its 5' end to its 3' end. 
C) The process is extremely fast once it is initiated. 
D) The process occurs in the nucleus of a eukaryotic cell. 
E) The entire template molecule is represented in the product. 
A) It uses RNA polymerase. 
B) It makes a new molecule from its 5' end to its 3' end. 
C) The process is extremely fast once it is initiated. 
D) The process occurs in the nucleus of a eukaryotic cell. 
E) The entire template molecule is represented in the product.

Question 11

The following information should be used for the next few questions.
A part of an mRNA molecule with the following sequence is being read by a ribosome: 5' CCG-ACG 3' (mRNA). 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.
  
-The dipeptide that will form will be

Accepted Answer

A) cysteine-alanine. 
B) proline-threonine. 
C) glycine-cysteine. 
D) alanine-alanine. 
E) threonine-glycine. 
A) cysteine-alanine. 
B) proline-threonine. 
C) glycine-cysteine. 
D) alanine-alanine. 
E) threonine-glycine.

Question 12

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 13

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 14

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 15

What must be included, in addition to the coding exons of the gene, in order for the expression of a eukaryotic gene engineered into a bacterial colony?

Accepted Answer

A) the introns 
B) eukaryotic polymerases 
C) a bacterial promoter sequence 
D) eukaryotic ribosomal subunits 
E) eukaryotic tRNAs 
A) the introns 
B) eukaryotic polymerases 
C) a bacterial promoter sequence 
D) eukaryotic ribosomal subunits 
E) eukaryotic tRNAs

Question 16

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 adenosine triphosphate and guanosine triphosphate. How many artificial mRNA 3 nucleotide codons would be possible?

Accepted Answer

A) 3 
B) 4 
C) 8 
D) 16 
E) 64 
A) 3 
B) 4 
C) 8 
D) 16 
E) 64

Question 17

The process of translation, whether in prokaryotes or eukaryotes, requires tRNAs, amino acids, ribosomal subunits, and which of the following?

Accepted Answer

A) polypeptide factors plus ATP 
B) polypeptide factors plus GTP 
C) polymerases plus GTP 
D) SRP plus chaperones 
E) signal peptides plus release factor 
A) polypeptide factors plus ATP 
B) polypeptide factors plus GTP 
C) polymerases plus GTP 
D) SRP plus chaperones 
E) signal peptides plus release factor

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

The "universal" genetic code is now known to have exceptions. Evidence for this can be found if which of the following is true?

Accepted Answer

A) If UGA, usually a stop codon, is found to code for an amino acid such as tryptophan (usually coded for by UGG only). 
B) If one stop codon, such as UGA, is found to have a different effect on translation than another stop codon, such as UAA. 
C) If prokaryotic organisms are able to translate a eukaryotic mRNA and produce the same polypeptide. 
D) If several codons are found to translate to the same amino acid, such as serine. 
E) If a single mRNA molecule is found to translate to more than one polypeptide when there are two or more AUG sites. 
A) If UGA, usually a stop codon, is found to code for an amino acid such as tryptophan (usually coded for by UGG only). 
B) If one stop codon, such as UGA, is found to have a different effect on translation than another stop codon, such as UAA. 
C) If prokaryotic organisms are able to translate a eukaryotic mRNA and produce the same polypeptide. 
D) If several codons are found to translate to the same amino acid, such as serine. 
E) If a single mRNA molecule is found to translate to more than one polypeptide when there are two or more AUG sites.

Question 20

Transcription in eukaryotes requires which of the following in addition to RNA polymerase?

Accepted Answer

A) the protein product of the promoter 
B) start and stop codons 
C) ribosomes and tRNA 
D) several transcription factors (TFs) 
E) aminoacyl synthetase 
A) the protein product of the promoter 
B) start and stop codons 
C) ribosomes and tRNA 
D) several transcription factors (TFs) 
E) aminoacyl synthetase

Exam 17: From Gene to Protein

Of the following, which is the most current description of a gene?

The term polyribosome refers to

The following questions refer to this table of codons. -A possible sequence of nucleotides in the template strand of DNA that would code for the polypeptide sequence phe-leu-ile-val would be

The anticodon of a particular tRNA molecule is

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

Use the following model of a eukaryotic transcript to answer the next few questions. 5' UTR E₁ I₁ E₂ I₂ E₃ I₃ E₄ UTR 3' -When the spliceosome binds to elements of this structure, where can it attach?

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

What is the role of UV light in this circumstance?

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?

In comparing DNA replication with RNA transcription in the same cell, which of the following is true only of replication?

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

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

What must be included, in addition to the coding exons of the gene, in order for the expression of a eukaryotic gene engineered into a bacterial colony?

The process of translation, whether in prokaryotes or eukaryotes, requires tRNAs, amino acids, ribosomal subunits, and which of the following?

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

The "universal" genetic code is now known to have exceptions. Evidence for this can be found if which of the following is true?

Transcription in eukaryotes requires which of the following in addition to RNA polymerase?

Introduction: Evolution and Themes of Biology

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

Dna Tools and 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 Signalling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behaviour

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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