Question 1

The first cloned cat,called Carbon Copy,was a calico,but she looked significantly different from her female parent.Why?

Accepted Answer

A) The environment, as well as genetics, affects phenotypic variation. 
B) Fur-colour genes in cats are influenced by differential acetylation patterns. 
C) Cloned animals have been found to have a higher frequency of transposon activation. 
D) X inactivation in the embryo is random and produces different patterns. 
E) The telomeres of the parent's chromosomes were shorter than those of an embryo. 
A) The environment, as well as genetics, affects phenotypic variation. 
B) Fur-colour genes in cats are influenced by differential acetylation patterns. 
C) Cloned animals have been found to have a higher frequency of transposon activation. 
D) X inactivation in the embryo is random and produces different patterns. 
E) The telomeres of the parent's chromosomes were shorter than those of an embryo. D

Question 2

For a particular microarray assay (DNA chip),cDNA has been made from the mRNAs of a dozen patients' breast tumour biopsies.The researchers will be looking for

Accepted Answer

A) a particular gene that is amplified in all or most of the patient samples. 
B) a pattern of fluorescence that indicates which cells are overproliferating. 
C) a pattern shared among some or all of the samples that indicates gene expression differing from control samples. 
D) a group of cDNAs that act differently from those on the rest of the grid. 
E) a group of cDNAs that match those in non-breast cancer control samples from the same population. 
A) a particular gene that is amplified in all or most of the patient samples. 
B) a pattern of fluorescence that indicates which cells are overproliferating. 
C) a pattern shared among some or all of the samples that indicates gene expression differing from control samples. 
D) a group of cDNAs that act differently from those on the rest of the grid. 
E) a group of cDNAs that match those in non-breast cancer control samples from the same population. C

Question 3

Which of the following modifications is least likely to alter the rate at which a DNA fragment moves through a gel during electrophoresis?

Accepted Answer

A) altering the nucleotide sequence of the DNA fragment 
B) methylating the cytosine bases within the DNA fragment 
C) increasing the length of the DNA fragment 
D) decreasing the length of the DNA fragment 
E) neutralizing the negative charges within the DNA fragment 
A) altering the nucleotide sequence of the DNA fragment 
B) methylating the cytosine bases within the DNA fragment 
C) increasing the length of the DNA fragment 
D) decreasing the length of the DNA fragment 
E) neutralizing the negative charges within the DNA fragment A

Question 4

A principal problem with inserting an unmodified mammalian gene into a plasmid,and then getting that gene expressed in bacteria,is that

Accepted Answer

A) prokaryotes use a different genetic code from that of eukaryotes. 
B) bacteria translate polycistronic messages only. 
C) bacteria cannot remove eukaryotic introns. 
D) bacterial RNA polymerase cannot make RNA complementary to mammalian DNA. 
E) bacterial DNA is not found in a membrane-bounded nucleus and is therefore incompatible with mammalian DNA. 
A) prokaryotes use a different genetic code from that of eukaryotes. 
B) bacteria translate polycistronic messages only. 
C) bacteria cannot remove eukaryotic introns. 
D) bacterial RNA polymerase cannot make RNA complementary to mammalian DNA. 
E) bacterial DNA is not found in a membrane-bounded nucleus and is therefore incompatible with mammalian DNA.

Question 5

For applications in gene therapy,what is the most favorable characteristic of retroviruses?

Accepted Answer

A) Retroviruses have an RNA genome. 
B) Retroviruses possess reverse transcriptase. 
C) DNA copies of retroviral genomes become integrated into the genome of the infected cell. 
D) Retroviruses mutate often. 
E) Retroviruses are not immunogenic. 
A) Retroviruses have an RNA genome. 
B) Retroviruses possess reverse transcriptase. 
C) DNA copies of retroviral genomes become integrated into the genome of the infected cell. 
D) Retroviruses mutate often. 
E) Retroviruses are not immunogenic.

Question 6

-The segment of DNA shown in the figure above has restriction sites I and II,which create restriction fragments A,B,and C.Which of the gels produced by electrophoresis shown below best represents the separation and identity of these fragments?

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 7

How difficult is it to clone a plant?

Accepted Answer

A) very difficult, since retroviruses are needed 
B) easy, as even mature differentiated cells are totipotent 
C) easy, as even mature differentiated cells a pluripotent 
D) impossible, since restriction enzymes prevent gene duplication 
E) it depends entirely on the age of the plant 
A) very difficult, since retroviruses are needed 
B) easy, as even mature differentiated cells are totipotent 
C) easy, as even mature differentiated cells a pluripotent 
D) impossible, since restriction enzymes prevent gene duplication 
E) it depends entirely on the age of the plant

Question 8

Use the following information to answer the next few questions.
A eukaryotic gene has "sticky ends" produced by the restriction endonuclease EcoRI.The gene is added to a mixture containing EcoRI and a bacterial plasmid that carries two genes conferring resistance to ampicillin and tetracycline.The plasmid has one recognition site for EcoRI located in the tetracycline resistance gene.This mixture is incubated for several hours,exposed to DNA ligase,and then added to bacteria growing in nutrient broth.The bacteria are allowed to grow overnight and are streaked on a plate using a technique that produces isolated colonies that are clones of the original.Samples of these colonies are then grown in four different media: nutrient broth plus ampicillin,nutrient broth plus tetracycline,nutrient broth plus ampicillin and tetracycline,and nutrient broth without antibiotics.
-Bacteria containing a plasmid into which the eukaryotic gene has integrated would grow in

Accepted Answer

A) the nutrient broth only. 
B) the nutrient broth and the tetracycline broth only. 
C) the nutrient broth, the ampicillin broth, and the tetracycline broth. 
D) all four types of broth. 
E) the ampicillin broth and the nutrient broth. 
A) the nutrient broth only. 
B) the nutrient broth and the tetracycline broth only. 
C) the nutrient broth, the ampicillin broth, and the tetracycline broth. 
D) all four types of broth. 
E) the ampicillin broth and the nutrient broth.

Question 9

Breast tumour biopsy specimens can be typed for a number of gene expression patterns.Together,these can provide risk analysis for the likely aggressive growth and metastasis of the tumour.How can this most help the physician and patient?

Accepted Answer

A) Some patients want to know as much as possible. 
B) This can help them to decide whether and what kind of chemotherapy is warranted. 
C) This can help them decide whether the tumour should be removed. 
D) Some physicians may use the information to decide what to do, but not tell the patient. 
E) This can help to aggregate health statistics. 
A) Some patients want to know as much as possible. 
B) This can help them to decide whether and what kind of chemotherapy is warranted. 
C) This can help them decide whether the tumour should be removed. 
D) Some physicians may use the information to decide what to do, but not tell the patient. 
E) This can help to aggregate health statistics.

Question 10

Assume that you are trying to insert a gene into a plasmid.Someone gives you a preparation of genomic DNA that has been cut with restriction enzyme X.The gene you wish to insert has sites on both ends for cutting by restriction enzyme Y.You have a plasmid with a single site for Y,but not for X.Your strategy should be to

Accepted Answer

A) insert the fragments cut with restriction enzyme X directly into the plasmid without cutting the plasmid. 
B) cut the plasmid with restriction enzyme X and insert the fragments cut with restriction enzyme Y into the plasmid. 
C) cut the DNA again with restriction enzyme Y and insert these fragments into the plasmid cut with the same enzyme. 
D) cut the plasmid twice with restriction enzyme Y and ligate the two fragments onto the ends of the DNA fragments cut with restriction enzyme X. 
E) cut the plasmid with restriction enzyme X and then insert the gene into the plasmid. 
A) insert the fragments cut with restriction enzyme X directly into the plasmid without cutting the plasmid. 
B) cut the plasmid with restriction enzyme X and insert the fragments cut with restriction enzyme Y into the plasmid. 
C) cut the DNA again with restriction enzyme Y and insert these fragments into the plasmid cut with the same enzyme. 
D) cut the plasmid twice with restriction enzyme Y and ligate the two fragments onto the ends of the DNA fragments cut with restriction enzyme X. 
E) cut the plasmid with restriction enzyme X and then insert the gene into the plasmid.

Question 11

As genetic technology makes testing for a wide variety of genotypes possible,which of the following is likely to be an increasingly troublesome issue?

Accepted Answer

A) use of genotype information to provide positive identification of criminals 
B) using technology to identify genes that cause criminal behaviours 
C) the need to legislate for the protection of the privacy of genetic information 
D) discrimination against certain racial groups because of major genetic differences 
E) alteration of human phenotypes to prevent early disease 
A) use of genotype information to provide positive identification of criminals 
B) using technology to identify genes that cause criminal behaviours 
C) the need to legislate for the protection of the privacy of genetic information 
D) discrimination against certain racial groups because of major genetic differences 
E) alteration of human phenotypes to prevent early disease

Question 12

Why might using retroviral vectors for gene therapy increase the patient's risk of developing cancer?

Accepted Answer

A) Retroviral vectors might introduce proteins from the virus. 
B) Retroviral vectors might not express the genes that were introduced into a patient's cells. 
C) Retroviral vectors might not integrate their recombinant DNA into the patient's genome. 
D) Retroviral vectors might integrate recombinant DNA into the genome in ways that misregulate the expression of genes at or near the site of integration. 
E) Retroviral vectors might cause a strong immune response. 
A) Retroviral vectors might introduce proteins from the virus. 
B) Retroviral vectors might not express the genes that were introduced into a patient's cells. 
C) Retroviral vectors might not integrate their recombinant DNA into the patient's genome. 
D) Retroviral vectors might integrate recombinant DNA into the genome in ways that misregulate the expression of genes at or near the site of integration. 
E) Retroviral vectors might cause a strong immune response.

Question 13

Imagine that you compare two DNA sequences found in the same location on homologous chromosomes.On one of the homologs,the sequence is 5'AACTACGA3'.On the other homolog,the sequence is 5'AACTTCGA3'.Within a population,you discover that each of these sequences is common.Which of the following is most likely true about these sequences?

Accepted Answer

A) They contain an SNP that may be useful for genetic mapping. 
B) They identify a protein-coding region of a gene. 
C) They cause disease. 
D) They are part of a promoter sequence. 
E) They may be important for differentiation. 
A) They contain an SNP that may be useful for genetic mapping. 
B) They identify a protein-coding region of a gene. 
C) They cause disease. 
D) They are part of a promoter sequence. 
E) They may be important for differentiation.

Question 14

What characteristic of short tandem repeats (STRs)makes them useful for DNA fingerprinting?

Accepted Answer

A) The number of repeats varies widely from person to person or animal to animal. 
B) The sequence of DNA that is repeated varies significantly from individual to individual. 
C) The sequence variation is acted upon differently by natural selection in different environments. 
D) Every racial and ethnic group has inherited different short tandem repeats. 
E) Each STR can be correlated with a specific disease. 
A) The number of repeats varies widely from person to person or animal to animal. 
B) The sequence of DNA that is repeated varies significantly from individual to individual. 
C) The sequence variation is acted upon differently by natural selection in different environments. 
D) Every racial and ethnic group has inherited different short tandem repeats. 
E) Each STR can be correlated with a specific disease.

Question 15

Why are yeast cells frequently used as hosts for cloning?

Accepted Answer

A) They easily form colonies. 
B) They can remove exons from mRNA. 
C) They do not have plasmids. 
D) They are eukaryotic cells. 
E) Only yeast cells allow the gene to be cloned. 
A) They easily form colonies. 
B) They can remove exons from mRNA. 
C) They do not have plasmids. 
D) They are eukaryotic cells. 
E) Only yeast cells allow the gene to be cloned.

Question 16

For which of the following might RNAi more possibly be useful?

Accepted Answer

A) to raise the rate of production of a needed digestive enzyme 
B) to decrease the production from a harmful gain-of-function mutated gene 
C) to destroy an unwanted allele in a homozygous individual 
D) to form a knockout organism that will not pass the deleted sequence to its progeny 
E) to raise the concentration of a desired protein 
A) to raise the rate of production of a needed digestive enzyme 
B) to decrease the production from a harmful gain-of-function mutated gene 
C) to destroy an unwanted allele in a homozygous individual 
D) to form a knockout organism that will not pass the deleted sequence to its progeny 
E) to raise the concentration of a desired protein

Question 17

Use the following information to answer the next few questions.
A group of six students has taken samples of their own cheek cells,purified the DNA,and used a restriction enzyme known to cut at zero,one,or two sites in a particular gene of interest.
-Analysis of the data obtained shows that two students each have two fragments,two students each have three fragments,and two students each have one only.What does this demonstrate?

Accepted Answer

A) Each pair of students has a different gene for this function. 
B) The two students who have two fragments have one restriction site in this region. 
C) The two students who have two fragments have two restriction sites within this gene. 
D) The students with three fragments are said to have "fragile sites." 
E) Each of these students is heterozygous for this gene. 
A) Each pair of students has a different gene for this function. 
B) The two students who have two fragments have one restriction site in this region. 
C) The two students who have two fragments have two restriction sites within this gene. 
D) The students with three fragments are said to have "fragile sites." 
E) Each of these students is heterozygous for this gene.

Question 18

In order to identify a specific restriction fragment using a probe,what must be done?

Accepted Answer

A) The fragments must be separated by electrophoresis. 
B) The fragments must be treated with heat or chemicals to separate the strands of the double helix. 
C) The probe must be hybridized with the fragment. 
D) The fragments must be separated by electrophoresis and the fragments must be treated with heat or chemicals to separate the strands of the double helix. 
E) The fragments must be separated by electrophoresis, the fragments must be treated with heat or chemicals to separate the strands of the double helix, and the probe must be hybridized with the fragment. 
A) The fragments must be separated by electrophoresis. 
B) The fragments must be treated with heat or chemicals to separate the strands of the double helix. 
C) The probe must be hybridized with the fragment. 
D) The fragments must be separated by electrophoresis and the fragments must be treated with heat or chemicals to separate the strands of the double helix. 
E) The fragments must be separated by electrophoresis, the fragments must be treated with heat or chemicals to separate the strands of the double helix, and the probe must be hybridized with the fragment.

Question 19

What is the most important reason to sequence an entire genome of a model organism,such as that of C.elegans,a nematode?

Accepted Answer

A) it allows researchers to use the sequence to build a "better" nematode, which is resistant to disease. 
B) it allows research on a group of organisms we do not usually care much about. 
C) the nematode is a good animal model for trying out cures for viral illness. 
D) a sequence that is found to have a particular function in the nematode is likely to have a closely related function in vertebrates. 
E) a sequence that is found to have no introns in the nematode genome is likely to have acquired the introns from higher organisms. 
A) it allows researchers to use the sequence to build a "better" nematode, which is resistant to disease. 
B) it allows research on a group of organisms we do not usually care much about. 
C) the nematode is a good animal model for trying out cures for viral illness. 
D) a sequence that is found to have a particular function in the nematode is likely to have a closely related function in vertebrates. 
E) a sequence that is found to have no introns in the nematode genome is likely to have acquired the introns from higher organisms.

Question 20

Use the following information to answer the next few questions.
A eukaryotic gene has "sticky ends" produced by the restriction endonuclease EcoRI.The gene is added to a mixture containing EcoRI and a bacterial plasmid that carries two genes conferring resistance to ampicillin and tetracycline.The plasmid has one recognition site for EcoRI located in the tetracycline resistance gene.This mixture is incubated for several hours,exposed to DNA ligase,and then added to bacteria growing in nutrient broth.The bacteria are allowed to grow overnight and are streaked on a plate using a technique that produces isolated colonies that are clones of the original.Samples of these colonies are then grown in four different media: nutrient broth plus ampicillin,nutrient broth plus tetracycline,nutrient broth plus ampicillin and tetracycline,and nutrient broth without antibiotics.
-Bacteria that contain the plasmid,but not the eukaryotic gene,would grow

Accepted Answer

A) in the nutrient broth plus ampicillin, but not in the broth containing tetracycline. 
B) only in the broth containing both antibiotics. 
C) in the broth containing tetracycline, but not in the broth containing ampicillin. 
D) in all four types of broth. 
E) in the nutrient broth without antibiotics only. 
A) in the nutrient broth plus ampicillin, but not in the broth containing tetracycline. 
B) only in the broth containing both antibiotics. 
C) in the broth containing tetracycline, but not in the broth containing ampicillin. 
D) in all four types of broth. 
E) in the nutrient broth without antibiotics only.

Exam 20: DNA Tools and Biotechnology

The first cloned cat,called Carbon Copy,was a calico,but she looked significantly different from her female parent.Why?

For a particular microarray assay (DNA chip),cDNA has been made from the mRNAs of a dozen patients' breast tumour biopsies.The researchers will be looking for

Which of the following modifications is least likely to alter the rate at which a DNA fragment moves through a gel during electrophoresis?

A principal problem with inserting an unmodified mammalian gene into a plasmid,and then getting that gene expressed in bacteria,is that

For applications in gene therapy,what is the most favorable characteristic of retroviruses?

-The segment of DNA shown in the figure above has restriction sites I and II,which create restriction fragments A,B,and C.Which of the gels produced by electrophoresis shown below best represents the separation and identity of these fragments?

How difficult is it to clone a plant?

Breast tumour biopsy specimens can be typed for a number of gene expression patterns.Together,these can provide risk analysis for the likely aggressive growth and metastasis of the tumour.How can this most help the physician and patient?

As genetic technology makes testing for a wide variety of genotypes possible,which of the following is likely to be an increasingly troublesome issue?

Why might using retroviral vectors for gene therapy increase the patient's risk of developing cancer?

What characteristic of short tandem repeats (STRs)makes them useful for DNA fingerprinting?

Why are yeast cells frequently used as hosts for cloning?

For which of the following might RNAi more possibly be useful?

In order to identify a specific restriction fragment using a probe,what must be done?

What is the most important reason to sequence an entire genome of a model organism,such as that of C.elegans,a nematode?

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

From Gene to Protein

Regulation of Gene Expression

Viruses

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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