Question 1

When the function of the newly made polypeptide is to be secreted from the cell where it has been made, what must occur?

Accepted Answer

A) It must be translated by a ribosome that remains free of attachment to the ER. 
B) Its signal sequence must target it to the ER, from which it goes to the Golgi. 
C) It has a signal sequence that must be cleaved off before it can enter the ER. 
D) It has a signal sequence that targets it to the cell's plasma membrane where it causes exocytosis. 
E) Its signal sequence causes it to be encased in a vesicle as soon as it is translated. 
A) It must be translated by a ribosome that remains free of attachment to the ER. 
B) Its signal sequence must target it to the ER, from which it goes to the Golgi. 
C) It has a signal sequence that must be cleaved off before it can enter the ER. 
D) It has a signal sequence that targets it to the cell's plasma membrane where it causes exocytosis. 
E) Its signal sequence causes it to be encased in a vesicle as soon as it is translated.

Question 2

A frameshift mutation could result from

Accepted Answer

A) a base insertion only. 
B) a base deletion only. 
C) a base substitution only. 
D) deletion of three consecutive bases. 
E) either an insertion or a deletion of a base. 
A) a base insertion only. 
B) a base deletion only. 
C) a base substitution only. 
D) deletion of three consecutive bases. 
E) either an insertion or a deletion of a base.

Question 3

Which of the following is not true of a codon?

Accepted Answer

A) It consists of three nucleotides. 
B) It may code for the same amino acid as another codon. 
C) It never codes for more than one amino acid. 
D) It extends from one end of a tRNA molecule. 
E) It is the basic unit of the genetic code. 
A) It consists of three nucleotides. 
B) It may code for the same amino acid as another codon. 
C) It never codes for more than one amino acid. 
D) It extends from one end of a tRNA molecule. 
E) It is the basic unit of the genetic code.

Question 4

Which of the following is the first event to take place in translation in eukaryotes?

Accepted Answer

A) elongation of the polypeptide 
B) base pairing of activated methionine-tRNA to AUG of the messenger RNA 
C) binding of the larger ribosomal subunit to smaller ribosomal subunits 
D) covalent bonding between the first two amino acids 
E) the small subunit of the ribosome recognizes and attaches to the 5' cap of mRNA 
A) elongation of the polypeptide 
B) base pairing of activated methionine-tRNA to AUG of the messenger RNA 
C) binding of the larger ribosomal subunit to smaller ribosomal subunits 
D) covalent bonding between the first two amino acids 
E) the small subunit of the ribosome recognizes and attaches to the 5' cap of mRNA

Question 5

How does a plasma membrane protein become imbedded in the membrane?

Accepted Answer

A) Ribosomes attach to the plasma membrane and translation of the peptide occurs directly on the PM. 
B) Ribosomes enter the endoplasmic reticulum and make the proteins within the ER. 
C) Once the signal peptide is translated, the ribosome complex is escorted to the PM, translation continues and the peptide is inserted through a pore in the membrane. 
D) Once the signal peptide is translated, the ribosome complex is escorted to the ER, translation continues and the peptide is inserted through a pore in the membrane. 
E) Once completed, the protein is escorted to the PM and a chaperone protein pushes it in. 
A) Ribosomes attach to the plasma membrane and translation of the peptide occurs directly on the PM. 
B) Ribosomes enter the endoplasmic reticulum and make the proteins within the ER. 
C) Once the signal peptide is translated, the ribosome complex is escorted to the PM, translation continues and the peptide is inserted through a pore in the membrane. 
D) Once the signal peptide is translated, the ribosome complex is escorted to the ER, translation continues and the peptide is inserted through a pore in the membrane. 
E) Once completed, the protein is escorted to the PM and a chaperone protein pushes it in.

Question 6

The white fur colouration of the "spirit bear" of British Columbia, is a result of

Accepted Answer

A) a point mutation, leading to a missense protein. 
B) a point mutation leading to a nonsense protein. 
C) albinism. 
D) a deletion in the MC1 chromosome. 
E) hybridization with polar bears. 
A) a point mutation, leading to a missense protein. 
B) a point mutation leading to a nonsense protein. 
C) albinism. 
D) a deletion in the MC1 chromosome. 
E) hybridization with polar bears.

Question 7

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 8

If a protein is coded for by a single gene and this protein has six clearly defined domains, which number of exons below is the gene likely to have?

Accepted Answer

A) 1 
B) 5 
C) 8 
D) 12 
E) 14 
A) 1 
B) 5 
C) 8 
D) 12 
E) 14

Question 9

The nitrogenous base adenine is found in all members of which group?

Accepted Answer

A) proteins, triglycerides, and testosterone 
B) proteins, ATP, and DNA 
C) ATP, RNA, and DNA 
D) α glucose, ATP, and DNA 
E) proteins, carbohydrates, and ATP 
A) proteins, triglycerides, and testosterone 
B) proteins, ATP, and DNA 
C) ATP, RNA, and DNA 
D) α glucose, ATP, and DNA 
E) proteins, carbohydrates, and ATP

Question 10

Suppose that an induced mutation removes most of the 5' end of the 5' UTR. What might result?

Accepted Answer

A) Removal of the 5' UTR has no effect because the exons are still maintained. 
B) Removal of the 5' UTR also removes the 5' cap and the mRNA will quickly degrade. 
C) The 3' UTR will duplicate and one copy will replace the 5' end. 
D) The first exon will not be read because I₁ will now serve as the UTR. 
E) Removal of the 5' UTR will result in the strand not binding to tRNAs. 
A) Removal of the 5' UTR has no effect because the exons are still maintained. 
B) Removal of the 5' UTR also removes the 5' cap and the mRNA will quickly degrade. 
C) The 3' UTR will duplicate and one copy will replace the 5' end. 
D) The first exon will not be read because I₁ will now serve as the UTR. 
E) Removal of the 5' UTR will result in the strand not binding to tRNAs.

Question 11

The TATA sequence is found approximately 25 nucleotides upstream from the start site of transcription. This most probably relates to which of the following?

Accepted Answer

A) its involvement with binding the transcription factor that helps place polymerase II in the correct location 
B) its direct binding of polymerase II 
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) its involvement with binding the transcription factor that helps place polymerase II in the correct location 
B) its direct binding of polymerase II 
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 12

Use the following information to answer the questions below.
Yeast is capable of synthesizing the amino acids necessary for survival and can grow on minimal media or enriched media easily. In both conditions, the colonies have a cream colour. The production of adenine is regulated by two genes, ADE1 and ADE2. If either of these genes is defective, adenine cannot be synthesized and the colony will look red (as a result of accumulation of precursors). A common undergraduate lab study is to irradiate yeast cells with ultra violet light from 2-5 sec up to 1-5 minutes, and see what will happen.
-If, after irradiating and growing cultures in minimal media, you see no red cultures, what can you conclude?

Accepted Answer

A) No mutation occurred. 
B) Mutations may have occurred but not in the adenine pathway. 
C) All the cultures were mutated. 
D) The mutants died because of a lack of adenine in the media. 
E) You didn't leave the cultures under UV long enough. 
A) No mutation occurred. 
B) Mutations may have occurred but not in the adenine pathway. 
C) All the cultures were mutated. 
D) The mutants died because of a lack of adenine in the media. 
E) You didn't leave the cultures under UV long enough.

Question 13

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) bonding of the anticodon to the codon and the attachment of amino acids to tRNAs. 
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) bonding of the anticodon to the codon and the attachment of amino acids to tRNAs.

Question 14

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 15

Which of the following nucleotide triplets best represents a codon?

Accepted Answer

A) a triplet separated spatially from other triplets 
B) a triplet that has no corresponding amino acid 
C) a triplet at the opposite end of tRNA from the attachment site of the amino acid 
D) a triplet in the same reading frame as an upstream AUG 
E) a sequence in tRNA at the 3' end 
A) a triplet separated spatially from other triplets 
B) a triplet that has no corresponding amino acid 
C) a triplet at the opposite end of tRNA from the attachment site of the amino acid 
D) a triplet in the same reading frame as an upstream AUG 
E) a sequence in tRNA at the 3' end

Question 16

In an experimental situation, a student researcher inserts an mRNA molecule into a eukaryotic cell after he has removed its 5' cap and poly-A tail. Which of the following would you expect him to find?

Accepted Answer

A) The mRNA could not exit the nucleus to be translated. 
B) The cell recognizes the absence of the tail and polyadenylates the mRNA. 
C) The molecule is digested by restriction enzymes in the nucleus. 
D) The molecule is digested by exonucleases since it is no longer protected at the 5' end. 
E) The molecule attaches to a ribosome and is translated, but more slowly. 
A) The mRNA could not exit the nucleus to be translated. 
B) The cell recognizes the absence of the tail and polyadenylates the mRNA. 
C) The molecule is digested by restriction enzymes in the nucleus. 
D) The molecule is digested by exonucleases since it is no longer protected at the 5' end. 
E) The molecule attaches to a ribosome and is translated, but more slowly.

Question 17

Gene expression in the domain Archaea in part resembles that of bacteria and in part that of the domain Eukarya. In which way is it most like the domain Eukarya?

Accepted Answer

A) Domain Archaea have numerous transcription factors. 
B) Initiation of translation is like that of domain Eukarya. 
C) There is only one RNA polymerase. 
D) Transcription termination often involves attenuation. 
E) Post-transcriptional splicing is like that of Eukarya. 
A) Domain Archaea have numerous transcription factors. 
B) Initiation of translation is like that of domain Eukarya. 
C) There is only one RNA polymerase. 
D) Transcription termination often involves attenuation. 
E) Post-transcriptional splicing is like that of Eukarya.

Question 18

If a nucleotide substitution switched an A for a U, such that the codon was read as UAA instead of AAA, what would the effect be?

Accepted Answer

A) a silent mutation 
B) a missense mutation 
C) a nonsense mutation 
D) no mutation as nucleotides in the first position are interchangeable 
E) it would initiate a tumour 
A) a silent mutation 
B) a missense mutation 
C) a nonsense mutation 
D) no mutation as nucleotides in the first position are interchangeable 
E) it would initiate a tumour

Question 19

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 20

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 anticodon loop of the first tRNA that will complement this mRNA is

Accepted Answer

A) 3' GGC 5' 
B) 5' GGC 3' 
C) 5' ACG 3' 
D) 5' UGC 3' 
E) 3' UGC 5' 
A) 3' GGC 5' 
B) 5' GGC 3' 
C) 5' ACG 3' 
D) 5' UGC 3' 
E) 3' UGC 5'

Exam 17: From Gene to Protein

When the function of the newly made polypeptide is to be secreted from the cell where it has been made, what must occur?

A frameshift mutation could result from

Which of the following is not true of a codon?

Which of the following is the first event to take place in translation in eukaryotes?

How does a plasma membrane protein become imbedded in the membrane?

The white fur colouration of the "spirit bear" of British Columbia, is a result of

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

If a protein is coded for by a single gene and this protein has six clearly defined domains, which number of exons below is the gene likely to have?

The nitrogenous base adenine is found in all members of which group?

Suppose that an induced mutation removes most of the 5' end of the 5' UTR. What might result?

The TATA sequence is found approximately 25 nucleotides upstream from the start site of transcription. This most probably relates to which of the following?

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

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

Which of the following nucleotide triplets best represents a codon?

In an experimental situation, a student researcher inserts an mRNA molecule into a eukaryotic cell after he has removed its 5' cap and poly-A tail. Which of the following would you expect him to find?

Gene expression in the domain Archaea in part resembles that of bacteria and in part that of the domain Eukarya. In which way is it most like the domain Eukarya?

If a nucleotide substitution switched an A for a U, such that the codon was read as UAA instead of AAA, what would the effect be?

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

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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