BIO212 final

Which of the following sequences is most likely to be cut by a restriction enzyme?

AATATT TTATAA

Which of the following human diseases is caused by a virus that requires reverse transcriptase to transcribe its genome inside the host cell?

AIDS

Which of the following mechanisms is (are) used to coordiante the expression of multiple, related genes in eukaryotic cells?

A single repressor is able tot urn off several related genes

Which of the following best reflects what we know about how the flu virus moves between species?

An animal such as a pig is infected with more than one virus, genetic recombination occurs, the new virus mutates, the virus is passed to a new species such as a bird, and the virus mutates again and can now be transmitted to humans.

What is difference between an epidemic and a pandemic?

An epidemic is restricted to a local region; a pandemic is global.

Reproductive cloning of human embryos is generally considered unethical. However, on the subject of therapeutic cloning there is a wider divergence of opinion. Which of the following is a likely explanation?

Cloning to produce embryonic stem cells may lead to great medical benefits for many.

What is the function of reverse transcriptase in retroviruses?

It uses viral RNA as a template for DNA synthesis

If you already know that the infectious agent was either bacterial or viral, which method(s) listed above would allow you to distinguish between these two possibilities?

II or III

The phenomenon in which RNA molecules in a cell are destroyed if they have a sequence complementary to an introduced double-stranded RNA is called

RNA interference

For a repressible operon to be transcribed which of the following must occur?

RNA polymerase must bind to the promoter and the repressor must be inactive

Why do RNA viruses appear to have higher rates of mutation?

Replication of their genomes does not involve proofreading.

In large scale, genome-wide association studies in humans we look for _____.

SNPs where one allele is found more often in persons with a particular disorder than in healthy controls

Sequencing an entire genome, such as that of C. elegans, a nematode, is most important because _____.

Sequencing an entire genome, such as that of C. elegans, a nematode, is most important because _____.

What information is critical to the success of polymerase chain reaction (PCR) itself?

The DNA sequence of the ends of the DNA to be amplified must be known. B) The complete DNA sequence of the DNA to be amplified must be known.

Poliovirus is an RNA virus of the picornavirus group, which uses its RNA as mRNA. At its 5' end, the RNA genome has a viral protein (VPg) instead of a cap. This is followed by a nontranslated leader sequence, and then a single long protein-coding region (~7000 nucleotides), followed by a poly-A tail. Observations were made that used radioactive amino acid analogues. Short period use of the radioactive amino acids result in labeling of only very long proteins, while longer periods of labeling result in several different short polypeptides. What conclusion is most consistent with the results of the radioactive labeling experiment?

The RNA is only translated into a single long polypeptide, which is then cleaved into shorter ones

A researcher is using adult stem cells and comparing them to other adult cells from the same tissue. Which of the following is a likely finding?

The cells from the two sources exhibit different patterns of DNA methylation.

According to the lac operon model proposed by Jacob and Monod, what is predicted to occur if the operator is removed from the operon?

The lac operon would be transcribed continuously

Which of the following statements describes the lysogenic cycle of lambda phage?

The phage genome replicates along with the host genome

When she finds that the introduced strand separates into single-stranded RNAs, what other evidence of this single stranded RNA piece's activity can she find?

The rate of accumulation of the polypeptide encoded by the target mRNA is reduced

Which of the following represents a difference between viruses and viroids?

Viruses have capsids composed of protein, whereas viroids have no capsids.

In an experiment, DNA from the linear form of the bacteriophage Lambda was cut into fragments using the restriction enzyme Hind III. Restriction enzymes are isolated from bacteria and cut DNA in specific locations. Hind III cuts the Lambda DNA between the adenine nucleotides on the complimentary strands in a specific sequence, as indicated in the diagram, producing eight different size fragments. These fragments are then separated with an electrical current based on size after the DNA fragments are placed in a porous gel, a process called gel electrophoresis. Select an observation that best describes a correct aspect of the two processes of restriction digest and gel electrophoresis:

When separated on a gel, the pattern of DNA bands will be characteristic of those cut with Hind III, different restriction enzymes will not produce these same fragments.

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

X inactivation in the embryo is random and produces different patterns

Considering this evidence, which statement most likely explains how the O157:H7 population acquired the genetic variation that distinguishes the strain from harmless E. coli strains, such as those that reside in our intestines?

The virus infected the bacterium, and allowed the bacterial population to replicate with a copy of the phage genome in each new bacterium.

Which of the following supports the argument that viruses are nonliving?

They are not cellular

Which of the following is true of embryonic stem cells but not of adult stem cells?

They can give rise to all cell types in the organism.

Which of the following is one of the technical reasons why gene therapy is problematic?

Transferred genes may not have appropriately controlled activity.

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

bacteria cannot remove eukaryotic introns

One way to detect alternative splicing of transcripts from a given gene is to

compare the sequences of different mRNAs made from the given gene

Imagine that you compare two DNA sequences found in the same location on homologous chromosomes. On one of the homologs, the sequence is AACTACGA. On the other homolog, the sequence is AACTTCGA. Within a population, you discover that each of these sequences is common. These sequences _____.

contain an SNP that may be useful for genetic mapping

What would occur if the repressor of an inducible operon were mutated so that it could not bind the operator?

continous transcription of the operon's genes

A mutation that inactivates a regulatory gene of a repressible operon in an E. coli cell would result in

continuous trancscription of the structural gene controlled by that regulator

Which method is utilized by eukaryotes to control their gene expression that is NOT used in bacteria?

control of both RNA splicing and chormatin remodeling

In many ways, the regulation of the genes of a particular group of viruses will be similar to the regulation of the host genes. Therefore, which of the following would you expect of the genes of a bacteriophage?

control of more than one gene in an operon

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

a pattern shared among some or all of the samples that indicates gene expression differing from control samples

Which enzyme was used to produce the molecule in the figure above?

a restriction enzyme (endonuclease)

Bacterial cells protect their own DNA from restriction enzymes (endonucleases) by _____.

adding methyl groups to adenines and cytosines

DNA microarrays have made a huge impact on genomic studies because they _____.

allow the expression of many or even all of the genes in the genome to be compared at once

Altering patterns of gene expression in prokaryotes would most likely serve an organism's survival by

allowing an organism to adjust to changes in environmental conditions

In the form of gene therapy used successfully for severe combined immunodeficiency syndrome (SCID)-X1, the genetic engineering of human cells is done by _____.

isolating the patient's bone marrow cells, infecting them with genetically engineered viruses, and injecting them back into the patient's bone marrow

If she moves the repressor gene (lack), along with its promoter, to a position at some several thousand base pairs away from its normal position, we would expect the

lac operon will function normally

What is the main structural difference between enveloped and nonenveloped viruses?

eneveloped viruses have a phospholipid membrane outside their capsid, whereas nonenveloped viruses do not have a phospholipid membrane

In 1997, Dolly the sheep was cloned. Which of the following processes was used?

fusion of an adult cell's nucleus with an enucleated sheep egg, followed by incubation in a surrogate

Which of the following can be effective in preventing the onset of viral infection in humans?

getting vaccinated

One of her colleagues suggested she try increased methylation of C nucleotides in the DNA of promoters of a mammalian system. Which of the following results would she most likely see?

inactivation of the selected genes

Genetically engineered plants _____.

include transgenic rice plants that can grow in water of high salinity

Most repressor proteins are allosteric. Which of the following binds with the repressor to alter its conformation?

inducer

Which of the following, when taken up by a cell, binds to a repressor so that the repressor no longer binds to the operator?

inducer

Using retroviral vectors for gene therapy might increase the patient's risk of developing cancer because they might _____.

integrate recombinant DNA into the genome in ways that misregulate the expression of genes at or near the site of integration

If scientists are trying to use what they know about HSV to devise a means of protecting other people from being infected, which of the following would have the best chance of lowering the number of new cases of infection?

interfere with new viral replication in preexisting cases of HSV

Effective antiviral drugs are usually associated with which of the following properties?

interference with viral replication

Which of the following is most like the formation of identical twins?

organismal cloning

Among the newly discovered small noncoding RNAs, one type reestablishes methylation patterns during gamete formation and blocks expression of some transposes. These are known as

piRNA

Many identical copies of genes cloned in bacteria are produced as a result of

plasmid and bacterial cell replication

One possible use of transgenic plants is in the production of human proteins, such as vaccines. Which of the following is a possible hindrance that must be overcome?

prevention of transmission of plant allergens to the vaccine recipients

A researcher has used in vitro mutagenesis to mutate a cloned gene and then has reinserted the mutated gene into a cell. To have the mutated sequence disable the function of the gene, what must then occur?

recombination resulting in replacement of the wild type with the mutated gene

Extracellular glucose inhibits transcription of the lac operon by

reducing the levels of intracellular camp

Which of the following is a protein porduced by a regulatory gene?

repressor

A laboratory might use dideoxyribonucleotides to _____.

sequence a DNA fragment

The reason for differences in the sets of proteins expressed in a nerve and a pancreatic cell of the same individual is that nerve and pancreatic cells contain different

sets of regulatory proteins

The virus genome and viral proteins are assembled into virions during

the lytic cycle only

RNAi methodology uses double-stranded pieces of RNA to trigger breakdown of a specific mRNA or inhibit its translation. For which of the following might this technique be useful?

to decrease the production from a harmful mutated gene

If the yellow mottle virus begins its infection of a cell by using its genome as mRNA, which of the following would you expect to be able to measure?

translation rate

Why is it so important to be able to amplify DNA fragments when studying genes?

A gene may represent only a millionth of the cell's DNA.

In positive control of several sugar-metabolism-related operson, the catobolie activator protein (CAP) binds to DNA to stimulate transcriiption. What causes an increase in CAP activity in stimulating transcription?

A decrease in glucose and an increase in cAMP

Which of the following best describes siRNA?

A double-stranded RNA, one of whose strands can complement and inactivate a sequence of mRNA

Which of the following is characteristic of the lytic cycle?

A large number of phages are released at a time

In recent times, it has been shown that adult cells can be induced to become pluripotent stem cells (iPS). To make this conversion, what has been done to the adult cells?

A retrovirus is used to introduce four specific regulatory genes.

Plasmids are used as vectors in plant and bacterial genetic engineering. However, there is a major difference in the fate of genes introduced into bacteria on most bacterial plasmids and into plants on tumor-inducing (Ti) plasmids. What is this difference?

Bacterial plasmids and the genes they carry usually are not integrated into the chromosome; Ti plasmids and the genes they carry are integrated into the chromosome.

Suppose an experimenter becomes proficient with a technique that allows her to move DNA sequences within a prokaryotic genome. If she moves the promoter for the lac operon to the region between the beta galactosidase (lacZ) gene and teh permease (lacY) gene, which of the following would be likely?

Beta galactosidase will not be produced

CAP is said to be responsible for positive regulation of the lac operon because

CAP boudn to the cap-binding site increases the frequency of transcription initiation

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

DNA copies of retroviral genomes become integrated into the genome of the infected cell.

Which of the following is in the correct order for one cycle of polymerase chain reaction (PCR)?

Denature DNA; anneal primers; extend primers.

One predicted aspect of climate change is that climates, including precipitation and temperature, over most of the Earth will become more variable. Which of the following is a good crop genetic engineering strategy if this is true?

Genetically engineer several genotypes within single crop types.

Why do scientists consider HIV to be an emerging virus?

HIV suddenly became apparent and widespread in the 1980s.

Which of the following processes within viral replication is the greatest source of genetic variation in RNA virus populations?

High mutation rate due to lack of proofreading of RNA genome replication errors.

Let us suppose that someone is successful at producing induced pluripotent stem cells (iPS) for replacement of pancreatic insulin-producing cells for people with type 1 diabetes. Which of the following could still be problems?

I, II, and III

What is the most logical sequence of steps for splicing foreign DNA into a plasmid and inserting the plasmid into a bacterium?

III, II, IV, V, I

DNA sequencing has transformed our understanding of genes, genomes and evolution. Which of the following statements comparing two common sequencing techniques, the chain termination method and next generation sequencing is TRUE?

In the chain termination method, the order of bases is detected by fluorescently labeling each dideoxy-nucleotide in a different color, while next generation sequencing determines the order of bases by detecting the release of PPi during the formation of the phosphodiester bond.

Silencing of selected genes is often done using RNA interference (RNAi). Which of the following questions would NOT be answered with this process?

Is gene HA292 expressed in individuals for a disorder in humans?

There is a mutation in the repressor that ressults in a molecule known as a super-repressor because it represses the lac operon permanently. Which of these would characterize such a mutant?

It cannot bind to the inducer

The final step in a Sanger DNA sequencing reaction is to run the DNA fragments on a gel. What purpose does this serve?

It separates DNA fragments generated during the sequencing reaction based on one- nucleotide differences in their size.

Scientists developed a set of guidelines to address the safety of DNA technology. Which of the following is one of the adopted safety measures?

Microorganisms used in recombinant DNA experiments are genetically crippled to ensure that they cannot survive outside of the laboratory.

Will treating a viral infection with antibiotics affect the course of the infection?

No; antibiotics work by inhibiting enzymes specific to bacteria. Antibiotics have no effect on eukaryotic or virally encoded enzymes.

Organisms share many conserved core processes and features, including transcription and translation using a uniform genetic code. Scientists have used these shared processes and features in biotechnology. For example, for the process of some transformations, a plasmid is constructed when a eukaryotic gene of interest is added with an antibiotic resistant gene such beta-lactamase, which is used for ampicillin resistance. This plasmid is then inserted into a prokaryotic bacterial cell, such as E-coli, through a transformation process that leads to the production of the product protein from the eukaryotic organism. To culture the bacteria and obtain the protein product, the bacteria must grow. Select the appropriate condition to determine if the plasmid has entered the E-coli bacterial cell.

Nutrient broth to which ampicillin has been added.

Pax-6 is a gene that is involved in eye formation in many invertebrates, such as Drosophila. Pax-6 is also found in vertebrates. A Pax-6 gene from a mouse can be expressed in a fly and the protein (PAX-6) leads to a compound fly eye. This information suggests which of the following?

Pax-6 is highly conserved and shows shared evolutionary ancestry.

What is the most likely explanation of why this virus contained sequences from bird, pig, and human viruses?

Related viruses can undergo genetic recombination if the RNA genomes mix and match during viral assembly.

HIV is inactivated in the laboratory after a few minutes of sitting at room temperature, but the flu virus is still active after sitting for several hours. What are the practical consequences of these findings?

The flu virus can be transmitted more easily from person to person than HIV

Imagine that you've isolated a yeast mutant that contains histones resistant to acetylation. What phenotype do you predict for this mutant?

The mutant will show low levels of gene expression

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

The number of repeats varies widely from person to person or animal to animal.

If she moves the operator to the far end of the operon, past the transacetylase gene, which of the following would likely occur when the cell is exposed to lactose?

The structural genes will be transcribed continuously

If a viral host cell has a mutation that interferes with the addition of carbohydrates to proteins in the Golgi, which of the following could likely result?

The viral envelope proteins would not be glycosylated and might not arrive at the host plasma membrane.

In electron micrographs of HSV infection, it can be seen that the intact virus initially reacts with cell surface proteoglycans then with specific receptors. This is later followed by viral capsids docking with nuclear pores. Afterward, the capsids go form being full to being "empty." Which of the following best fits these observations?

The viral envelope mediates entry into the cell, the capsid mediates entry into the nuclear membrane, and the genome is all that enters the nucleus

Viruses use the host's machinery to make copies of themselves. However, some human viruses require a type of replication that humans do not normally have. For example, humans normally do not have the ability to convert RNA into DNA. How can these types of viruses infect humans, when human cells cannot perform a particular role that the virus requires?

The viral genome codes for specialized enzymes not in the host.

In animals, what is the difference between reproductive cloning and therapeutic cloning?

Therapeutic cloning supplies cells for repair of diseased or injured organs.

Which of the following is most likely to have a small protein called ubiquitin attached to it?

a cyclin protein, that usually acts in G1, in a cell that is in G2

A person is most likely to recover from a viral infection if the infected cells _____.

can undergo normal cell division

Which of the following problems with animal cloning might result in premature death of the clones?

abnormal gene regulation due to variant methylation

Not long ago, it was believed that a count of the number of protein-coding genes would provide a count of the number of proteins produced in any given eukaryotic species. This is incorrect, largely due to the discover of widespread

alternative splicing

Which of the following viruses would most likely have reverse transcriptase?

an RNA-based lysogenic virus

The primary difference between enhancers and promoter-proximal elements is that enhancers

are at considerable distances form the promoter; promoter-proximal elemetns are close to the promoter

Yeast cells are frequently used as hosts for cloning because they _____.

are eukaryotic cells

Some time later, she finds that introduced strand separates into single-stranded RNAs, one of which is degraded. What does this enable the remaing strand to do?

bind to complementary regions of target mRNAs

In eukaryotes, general transcription factors

bind to other proteins or to the TATA box

Steroid hormones produce their effect in cells by

binding to intracellular receptors and promoting transcirption of specific genes

The trp repressor blocks transcription of the trp operon when the repressor

bins to the tryptophan

The first class of drugs developed to treat AIDS, such as AZT, were known as reverse transcriptase inhibitors. They worked because they _____.

bonded to the viral reverse transcriptase enzyme, thus preventing the virus from making a DNA copy of its RNA genome

Transgenic mice are useful to human researchers because they _____.

can be valuable animal models of human disease

Viral infections in plants

can spread within a plant via plasmodesmata

Which of the following accounts for someone who has had regular herpesvirus-mediated col sore or genital sore flare-ups?

copies of the herpesvirus genome permanently maintained in host nuclei

A lack of which molecule would result in a cell's inability to "turn off" genes?

corepressor

In one set of experiments she succeeded in increasing acetlyation of histone tails. Which of the following results would she most likely see?

decreased chromatin condensation

A researcher lyses a cell that contains nucleic acid molecules and capsomeres of tobacco mosaic virus (TMV). The cell contents are left in a covered test tube overnight. The next day this mixture is sprayed on tobacco plants. We expect that the plants would _____.

develop the typical symptoms of TMV infection

If you already know that the infectious agent was either a viroid or a prion, which method(s) listed above would allow you to distinguish between these two possibilities?

either I or IV

To introduce a particular piece of DNA into an animal cell, such as that of a mouse, you would most likely be successful with which of the following methods?

electroporation followed by recombination

DNA methylation and histone acetylation are examples of

epigenetic phenomena

Which of the following uses labeled probes to visualize the expression of genes in whole tissues and organisms?

in situ hybridization

The reason for using Taq polymerase for PCR is that _____.

it is heat stable and can withstand the heating step of PCR

Gene therapy requires _____.

knowledge and availability of the normal allele of the defective gene, an ability to introduce the normal allele into the patient, and an ability to express the introduced gene at the correct level, and time, and tissue site within the patient

What are prions?

misfolded versions of normal protein that can cause disease

To make a vaccine against mumps, measles, or rabies, which type of viruses would be useful?

negative-sense ssRNA viruses

At the beginning of this century there was a general announcement regarding the sequencing of the human genome and the genomes of many other multicellular eukaryotes. Many people were surprised that the number of protein-coding equences was much smaller than they had expected. Which of the following could account for much of the DNA that is not coding for proteins?

non-protein-coding DNA that is transcribed into several kinds of small RNAs with biological function

A virus consisting of a single strand of RNA, which is transcribed into complementary DNA, is a _____.

retrovirus

Which viruses have single stranded RNA that acts as a template for DNA synthesis?

retroviruses

Which of the following is required to make complementary DNA (cDNA) from RNA?

reverse transcriptase

A gene that contains introns can be made shorter (but remain functional) for genetic engineering purposes by using _____.

reverse transcriptase to reconstruct the gene from its mRNA

Which of the following could use reverse transcriptase to transcribe its genome?

ssRNA

Transcription of structural genes in an inducible operon

starts when the pathway's substrate is present

A population of viruses with similar characteristics is called a _____.

strain

The lactose operon is likely to be transcribed

the cyclic AMP and lactose levels are both high within the cell

The host range of a virus is determined by

the proteins on its surface and that of the host

Gene expression is often assayed by measuring the level of mRNA produced from a gene. If one is interested in knowing the amount of a final active gene product, a potential problem of this method is that it ignores the possibility of

translational control

The difference between vertical and horizontal transmission of plant viruses is that vertical transmission is _____.

transmission of a virus from a parent plant to its progeny, and horizontal transmission is one plant spreading the virus to another plant

Viruses

use the host cell to copy themselves and make viral proteins