Ap bio dna test

normally leads to formation of head structures.

Absence of bicoid mRNA from a Drosophila egg leads to the absence of anterior larval body parts and mirror-image duplication of posterior parts. This is evidence that the product of the bicoid gene

reverse transcriptase to reconstruct the gene from its mRNA.

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

colorectal only

A genetic test to detect predisposition to cancer would likely examine the APC gene for involvement in which type(s) of cancer?

Y. X. y

A linear piece of viral DNA of 8 kb can be cut with either of two restriction enzymes (X and Y). These are subjected to electrophoresis and produce the following bands: Cutting the same 8 kb piece with both enzymes together results in bands at 4.0, 2.5, 1.0, and 0.5. Of the possible arrangements of the sites given below, which one is most likely?

promoter

A mutation in this section of DNA could influence the binding of RNA polymerase to the DNA:

a. continuous transcription of the structural gene controlled by that regulator.

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

bacteria cannot remove eukaryotic introns.

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

chemical modifications of histones and DNA methylation

Differentiation of cells is not easily reversible because it involves

methylation of the DNA is maintained because methylation enzymes act at DNA sites where one strand is already methylated and thus correctly methylates daughter strands after replication.

During DNA replication,

a. histone acetylation of nucleosomes

Eukaryotic cells can control gene expression by which of the following mechanisms?

retroviruses that require a DNA intermediate

Given Baltimore's scheme, a positive sense single-stranded RNA virus such as the polio virus would be most closely related to which of the following?

d. It stimulates the binding of RNA polymerase to the promoter.

How does active CAP induce expression of the genes of the lactose operon?

restriction enzyme recognition sites between the alleles

RFLP analysis can be used to distinguish between alleles based on differences in which of the following?

host cells lack enzymes that can replicate the viral genome.

RNA viruses require their own supply of certain enzymes because

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

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?

gel electrophoresis

Restriction fragments of DNA are typically separated from one another by which process

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

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

a sequence that is found to have a particular function in the nematode is likely to have a closely related function in vertebrates

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

d. binding to intracellular receptors and promoting transcription of specific genes.

Steroid hormones produce their effects in cells by

relaying a signal from a growth factor receptor

The cancer-causing forms of the Ras protein are involved in which of the following processes?

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

The lactose operon is likely to be transcribed when

YACs and BACs can carry much larger DNA fragments than ordinary plasmids can.

The major advantage of using artificial chromosomes such as YACs and BACs for cloning genes is that

Spatial axes (anterior posterior, etc.) begin to be determined.

The researcher continues to study the reactions of the embryo to these new proteins and you hypothesize that he is most likely to see which of the following (while embryonic genes are still not being expressed)?

the resulting new polypeptides are due to translation of maternal mRNAs

The researcher in question measures the amount of new polypeptide production in embryos from 2— 8 hours following fertilization and the results show a steady and significant rise in polypeptide concentration over that time. The researcher concludes that

d. The substance is produced in region 1 and diffuses toward region 5.

The researcher measures the concentration of the polypeptides from different regions in the early embryo and finds the following pattern (darker shading = greater concentration):

antibodies against specific proteins not found in the host membranes

Viral envelopes can best be analyzed with which of the following techniques?

misfolded versions of normal brain protei

What are prions?

the occurrence of mRNAs for the production of tissue-specific proteins

What is considered to be the first evidence of differentiation in the cells of an embryo?

to cleave nucleic acids at specific sites

What is the enzymatic function of restriction enzymes?

c. III, II, IV, V, I

What is the most logical sequence of steps for splicing foreign DNA into a plasmid and inserting the plasmid into a bacterium? I. Transform bacteria with recombinant DNA molecule. II. Cut the plasmid DNA using restriction enzymes. III. Extract plasmid DNA from bacterial cells. IV. Hydrogen-bond the plasmid DNA to nonplasmid DNA fragments. V. Use ligase to seal plasmid DNA to nonplasmid DNA.

retroviruses

What is the name given to viruses that are single-stranded RNA that acts as a template for DNA synthesis?

continuous transcription of the operon's genes

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

all of the above

Which of the following can contribute to the development of cancer?

genetic material composed of nucleic acid

Which of the following characteristics, structures, or processes is common to both bacteria and viruses?

restriction enzymes

Which of the following cuts DNA molecules at specific locations?

They are spread throughout a plant by passing through the plasmodesmata

Which of the following describes plant virus infections?

It trims small double-stranded RNAs into molecules that can block translation.

Which of the following describes the function of an enzyme known as Dicer?

he newly emerging virus will die out rather quickly or will mutate to be far less lethal.

Which of the following is the most probable fate of a newly emerging virus that causes high mortality in its host?

centromere, telomeres, and an origin of replication

Yeast artificial chromosomes contain which of the following elements?

FISH study to determine the chromosomal location of all chromosome 22 q fragments

Which of the following would be a reasonably efficient technique for confirming the diagnosis of CML?

It could be used to create a complete genomic library.

Which of the following would not be true of cDNA produced using human brain tissue as the starting material?

I

Which treatment could definitively determine whether or not the component is a viroid?

IV only

Which treatment would you use to determine if the agent is a prion?

They cannot reproduce outside of a host cell.

Why are viruses referred to as obligate parasites?

they are eukaryotic cells

Why are yeast cells frequently used as hosts for cloning?

Replication of their genomes does not involve the proofreading steps of DNA replication.

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

The drug inhibits the specific thymine kinase receptor

Why would Gleevec most probably cause remission of the disease?

activator

This binds to a site in the DNA far from the promoter to stimulate transcription

repressor

This can inhibit transcription by blocking the binding of positively acting transcription factors to the DNA:

terminator

This is the site in the DNA located near the end of the final exon, encoding an RNA sequence that determines the 3' end of the transcript:

include a transgenic rice plant that can help prevent vitamin A deficiency.

genetically engineered plants

A researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture. One of her colleagues suggested she try increased methylation of C nucleotides in a mammalian system. Which of the following results would she most likely see?

inactivation of the selected genes

polymerase chain reaction (PCR)

paleontologist has recovered a bit of tissue from the 400-year-old preserved skin of an extinct dodo (a bird). The researcher would like to compare a specific region of the DNA from the sample with DNA from living birds. Which of the following would be most useful for increasing the amount of dodo DNA available for testing?

increased chromatin condensation

researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture. In one set of experiments she succeeded in decreasing methylation of histone tails. Which of the following results would she most likely see?

The lac operon will function normally.

she moves the repressor gene (lac I), along with its promoter, to a position at some several thousand base pairs away from its normal position, which will you expect to occur?

T4 protein and T4 DNA

A bacterium is infected with an experimentally constructed bacteriophage composed of the T2 phage protein coat and T4 phage DNA. The new phages produced would have

totipotent

A cell that remains entirely flexible in its developmental possibilities is said to be

corepressor

A lack of this nonprotein molecule would result in the inability of the cell to "turn off" genes

The plants would develop the typical symptoms of TMV infection.

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. Which of the following would be expected to occur?

b. Allolactose binds to the repressor protein.

Allolactose induces the synthesis of the enzyme lactase. An E. coli cell is presented for the first time with the sugar lactose (containing allolactose) as a potential food source. Which of the following occurs when the lactose enters the cell?

interference with the viral reproduction

Antiviral drugs that have become useful are usually associated with which of the following properties?

1.5

Approximately what proportion of the DNA in the human genome codes for proteins or functional RNA?

The need to legislate for the protection of the privacy of genetic information

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

c. exposing the bacteria to an antibiotic that kills cells lacking the resistant plasmid

Bacteria containing recombinant plasmids are often identified by which process?

in all four types of broth.

Bacteria that contain the plasmid, but not the eukaryotic gene, would grow

the nutrient broth only

Bacteria that do not take up any plasmids would grow on which media?

adding methyl groups to adenines and cytosines

How does a bacterial cell protect its own DNA from restriction enzymes?

cell's sensitivity to environmental cues such as light or heat.

Cell differentiation always involves the

to attach the DNA fragments to a permanent substrate

DNA fragments from a gel are transferred to a nitrocellulose paper during the procedure called Southern blotting. What is the purpose of transferring the DNA from a gel to a nitrocellulose paper

introduction of genetically engineered genes into human gametes

DNA technology has many medical applications. Which of the following is not done routinely at present?

all of the above

Emerging viruses arise by

post-transcriptional processing.

Expression of a cloned eukaryotic gene in a bacterial cell involves many challenges. The use of mRNA and reverse transcriptase is part of a strategy to solve the problem of

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

For a repressible operon to be transcribed, which of the following must occu

growth factor signaling to be hyperactive

Forms of the ras protein found in tumors usually cause which of the following?

had apparent success in treating disorders involving bone marrow cells.

Gene therapy

creation of products that will remove poisons from the human body

Genetic engineering is being used by the pharmaceutical industry. Which of the following is not currently one of the uses?

epigenetic phenomena

Genomic imprinting, DNA methylation, and histone acetylation are all examples of

increased concentrations of sugars such as arabinose in the cell

If glucose is available in the environment of E. coli, the cell responds with very low concentration of cAMP. When the cAMP increases in concentration, it binds to CAP. Which of the following would you expect would then be a measurable effect?

d. amino acid acts as a corepressor.

If a particular operon encodes enzymes for making an essential amino acid and is regulated like the trp operon, then the A) amino acid inactivates the repressor. B) enzymes produced are called inducible enzymes. C) repressor is active in the absence of the amino acid. D) amino acid acts as a corepressor. E) amino acid turns on transcription of the operon.

Beta galactosidase will be produced

If she moves the promoter for the lac operon to the region between the beta galactosidase gene and the permease gene, which of the following would be likely?

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

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

Centromeres will be euchromatic rather than heterochromatic and the cells will soon die in culture.

In a series of experiments, the enzyme Dicer has been inactivated in cells from various vertebrates, and the centromere is abnormally formed from chromatin. Which of the following is most likely to occur?

embryonic stem cells are totipotent, and adult stem cells are pluripotent

In animals, embryonic stem cells differ from adult stem cells in that

genes involved in control of the cell cycle

In colorectal cancer, several genes must be mutated for a cell to develop into a cancer cell. Which of the following kinds of genes would you expect to be mutated?

bind to other proteins or to a sequence element within the promoter called the TATA box.

In eukaryotes, general transcription factors

a. nonidentical genes that produce different versions of globins during development

In humans, the embryonic and fetal forms of hemoglobin have a higher affinity for oxygen than that of adults. This is due to

control of more than one gene in an operon

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 the bacteriophage?

a plasmid used to transfer DNA into a living cell.

In recombinant DNA methods, the term vector can refer to

alter the level of production of various enzymes

In response to chemical signals, prokaryotes can do which of the following?

rabies

Most human-infecting viruses are maintained in the human population only. However, a zoonosis is a disease that is transmitted from other vertebrates to humans, at least sporadically, without requiring viral mutation. Which of the following is the best example of a zoonosis?

express different genes.

Muscle cells differ from nerve cells mainly because they

homeotic genes

Mutations in these genes lead to transformations in the identity of entire body parts

inherited inability to repair UV-induced mutation

One hereditary disease in humans, called xeroderma pigmentosum (XP), makes homozygous individuals exceptionally susceptible to UV-induced mutation damage in the cells of exposed tissue, especially skin. Without extraordinary avoidance of sunlight exposure, patients soon succumb to numerous skin cancers. Which of the following best describes this phenomenon?

argeting siRNAs to disable the expression of an allele associated with autosomal dominant disease

One of the hopes for use of recent knowledge gained about non-coding RNAs lies with the possibilities for their use in medicine. Of the following scenarios for future research, which would you expect to gain most from RNAs?

The translocation requires breaks in both chromosomes 9 and 22, followed by fusion between the reciprocal pieces.

One of the human leukemias, called CML (chronic myelogenous leukemia) is associated with a chromosomal translocation between chromosomes 9 and 22 in somatic cells of bone marrow. Which of the following allows CML to provide further evidence of this multi-step nature of cancer?

prevention of transmission of plant allergens to the vaccine recipient

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?

The engineered cells, when reintroduced into the patient, find their way back to the bone marrow

One successful form of gene therapy has involved delivery of an allele for the enzyme adenosine deaminase (ADA) to bone marrow cells of a child with SCID, and delivery of these engineered cells back to the bone marrow of the affected child. What is one major reason for the success of this procedure as opposed to many other efforts at gene therapy?

a somatic plant cell can often give rise to a complete plant.

Plants are more readily manipulated by genetic engineering than are animals because

Changes in technology as well as our ability to determine how much of the DNA is expressed have now made this possible.

Since Watson and Crick described DNA in 1953, which of the following might best explain why the function of small RNAs is still being explained?

transcriptional control of gene expression.

The functioning of enhancers is an example of

differential gene expression.

The process of cellular differentiation is a direct result of

bind to the repressor protein and activate it.

The role of a metabolite that controls a repressible operon is to

repressor

This protein is produced by a regulatory gene:

other transcription factors

Transcription factors in eukaryotes usually have DNA binding domains as well as other domains also specific for binding. In general, which of the following would you expect many of them to be able to bind?

starts when the pathway's substrate is present.

Transcription of the structural genes in an inducible operon

can encode proteins that promote DNA repair or cell-cell adhesion

Tumor suppressor genes

DNA methylation and histone modification.

Two potential devices that eukaryotic cells use to regulate transcription are

size and shape of the capsid

Viral genomes vary greatly in size and may include from four genes to several hundred genes. Which of the following viral features is most apt to correlate with the size of the genome

inducer

When this is taken up by the cell, it binds to the repressor so that the repressor no longer binds to the operator:

a restriction enzyme

Which enzyme was used to produce the molecule in Figure 20.1?

copies of the herpesvirus genome permanently maintained in host nuclei

Which of the following accounts for someone who has had a herpesvirus-mediated cold sore or genital sore getting flare-ups for the rest of his or her life?

. C and D

Which of the following are probably sibling

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

Which of the following best describes siRNA?

. 2, 1, 4

Which of the following best describes the complete sequence of steps occurring during every cycle of PCR?

getting vaccinated

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

removal of the 5' cap

Which of the following experimental procedures is most likely to hasten mRNA degradation in a eukaryotic cell?

It is an activator for other genes.

Which of the following is characteristic of the product of the p53 gene

organismal cloning

Which of the following is most closely identical to the formation of twins?

a cyclin that usually acts in G1, now that the cell is in G2

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

Transferred genes may not have appropriately controlled activity.

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

a. ability of the infected cell to undergo normal cell division

Which of the following is the best predictor of how much damage a virus causes?

They make up the majority of cells of the tissue from which they are derived.

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

reverse transcriptase

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

organization of the genes into clusters, with local chromatin structures influencing the expression of all the genes at once

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

a. altering the nucleotide sequence of the DNA fragment

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

glycoproteins

Which of the following molecules make up the viral envelope?

abnormal regulation due to variant methylation

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

incubating DNA with restriction enzymes

Which of the following procedures would produce RFLPs?

gene cloning

Which of the following produces multiple identical copies of a gene for basic research or for large- scale production of a gene product?

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

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

DNA ligase

Which of the following seals the sticky ends of restriction fragments to make recombinant DNA

gel electrophoresis

Which of the following separates molecules by movement due to size and electrical charge?

GGCC CCGG

Which of the following sequences in double-stranded DNA is most likely to be recognized as a cutting site for a restriction enzyme?

cytoplasmic determinants such as mRNAs and proteins produced before fertilization

Which of the following serve as sources of developmental information?

is the same as the DNA in one of your heart cells.

Which of the following statements about the DNA in one of your brain cells is true?

The phage genome replicates along with the host genome.

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

D is the child of A and B.

Which of the following statements is most likely true?

prophages

Which of the following terms describes bacteriophage DNA that has become integrated into the host cell chromosome?

a. transcription

both eukaryotes and prokaryotes, gene expression is primarily regulated at the level of.

both euchromatin and histone acetylation.

eukaryotes, transcription is generally associated with

transcription

most cases, differentiation is controlled at which level?

A, B, and C are correct

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

decreased chromatin concentration

researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture. In one set of experiments using this procedure in Drosophila, she was readily successful in increasing phosphorylation of amino acids adjacent to methylated amino acids in histone tails. Which of the following results would she most likely see?

abnormalities of mouse embryos

researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture. She tried decreasing the amount of methylation enzymes in the embryonic stem cells and then allowed the cells to further differentiate. Which of the following results would she most likely see?

a YAC with appropriate cellular enzymes

researcher needs to clone a sequence of part of a eukaryotic genome in order to express the sequence and to modify the polypeptide product. She would be able to satisfy these requirements by using which of the following vectors?

an earlier age of onset in child one

there are two children born from the same parents, and child one inherits a predisposition to retinoblastoma (one of the mutations) and child two does not, but both children develop the retinoblastoma, which of the following would you expect?