Question 1

Genetically engineered crops in the United States

Accepted Answer

A) may soon be ready for commercial planting. 
B) have seen some limited commercial success. 
C) are currently available only for rice. 
D) are widespread for many major crop species. 
E) are the only types of crops now being planted.

Question 2

Figure 19.2 
-The answer set for this question shows a series of short amino acid sequences obtained from a protein.If you were faced with choosing one of these to design a probe for a particular gene,which would provide the simplest probe or probe set? (To answer this question,consult the codon table shown in the figure above ).

Accepted Answer

A) leucine-leucine-serine-leucine 
B) leucine-serine-proline-proline 
C) proline-methionine-proline-leucine 
D) tryptophan-methionine-tryptophan-tryptophan

Question 3

How can an amino acid sequence be used to design a gene-specific hybridization probe?

Accepted Answer

A) A portion of a polypeptide chain can be synthesized based on the amino acid sequence of the full protein. 
B) A protein can be purified,digested with proteases that cleave it at specific sites,and one of the peptide fragments can be used as a probe. 
C) All possible nucleotide sequences that could encode a portion of the polypeptide can be synthesized and used as probes.

Question 4

The genes needed for β-carotene synthesis are not normally expressed in endosperm.In the creation of golden rice,how did researchers ensure that these genes were expressed in rice endosperm?

Accepted Answer

A) The genes were injected only in the endosperm of rice grains. 
B) Agrobacterium cells were added only to rice grains,not to any other part of the plant. 
C) The protein-coding sequence of each gene was linked to a regulatory region of DNA that directed transcription in endosperm. 
D) The wild-type genes were mutated and new mutant alleles that are expressed only in endosperm were selected.

Question 5

Imagine that you are searching for the gene associated with nail-patella syndrome,a dominant genetic disorder that causes developmental abnormalities.In a large pedigree,you discover an association between nail-patella syndrome and a genetic marker that occurs in two different alleles,A and B.Fifteen individuals within this pedigree have nail-patella syndrome and are A/B heterozygotes for the marker.Thirty individuals within this pedigree don't suffer from nail-patella syndrome and are homozygous for the A marker allele.One individual within this pedigree has nail-patella syndrome and is also homozygous for the A marker allele.The most likely explanation for this exceptional individual is

Accepted Answer

A) a new mutation converted the disease-causing allele to the wild-type form. 
B) a new mutation converted the B allele of the marker to the A form. 
C) the exceptional nail-patella individual is haploid. 
D) recombination occurred between the nail-patella gene and marker gene in one of the parents of the exceptional individual.

Question 6

In early forensic applications of DNA fingerprinting,DNA was extracted from crime scene material,digested with restriction enzymes,and then used to prepare a Southern blot.Today,PCR is used in the early steps of forensic DNA analysis.What advantage does PCR provide over the former method?

Accepted Answer

A) PCR produces many more bands for fingerprint analysis,making it a more informative technique. 
B) PCR can cut DNA at many more sites than restriction enzymes can. 
C) PCR requires much less DNA for analysis. 
D) PCR can analyze DNA,proteins,and carbohydrates,whereas restriction enzyme analysis is limited to DNA.

Question 7

Transgenic mice

Accepted Answer

A) often provide valuable animal models of human disease. 
B) are essential for mapping human genes. 
C) are now used in place of bacteria for cloning human genes. 
D) were instrumental in pinpointing the location of the huntingtin gene.

Question 8

You ask your student to transfer a plasmid-free bacterial strain to multiple small tubes for long term storage.A short while later,your student admits that he did not use a clean sterile pipette to transfer the bacteria to the small tubes,but rather grabbed the same pipette he had just used to collect newly transformed bacteria.Why would this pose a problem?

Accepted Answer

A) Plasmids can be transferred between bacteria via pili. 
B) Newly transformed bacteria will actively undergo binary fission. 
C) Plasmid can contain genes that confer antibiotic resistance. 
D) Plasmids will incorporate into the chromosomal DNA.

Question 9

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

Accepted Answer

A) They might fail to introduce genes into any of the patient's cells. 
B) They might not express the genes that were introduced into a patient's cells. 
C) They might not integrate their recombinant DNA into the patient's genome. 
D) They might integrate recombinant DNA into the genome in ways that misregulate the expression of genes at or near the site of integration.

Question 10

How could the "demographic history of Neanderthal populations" be explored if mitochondrial DNA from other Neanderthal samples could be PCR amplified?

Accepted Answer

A) These Neanderthal sequences could be compared to those of modern humans to learn if they are closely related. 
B) These Neanderthal sequences could be compared to those of modern humans;the more they differ,the more distant the time of divergence between the Neanderthal and modern human lineages. 
C) These Neanderthal sequences could be compared to each other to see how much they differ;the more they differ,the greater the divergence between these populations. 
D) In the attempt to amplify other Neanderthal DNAs,those that amplify must be from more modern populations and those that don't are from more ancient populations.

Question 11

Since dideoxy sequencing is based on the chain termination,why are normal deoxynucleotides also included in the reaction?

Accepted Answer

A) to enhance the chain termination ability of the deoxynucleotides 
B) to provide a substrate for DNA polymerase 
C) to produce a range of DNA synthesis products that terminate at every occurrence of a particular base 
D) to create DNA synthesis products long enough to allow running a gel

Question 12

Why is it essential that genetic markers used in mapping disease genes be polymorphic?

Accepted Answer

A) If the marker isn't polymorphic,its position cannot be known. 
B) If the marker isn't polymorphic,it cannot be physically linked to a gene associated with human disease. 
C) If the marker isn't polymorphic,then it will not be inherited in any predictable manner. 
D) If the marker isn't polymorphic,then it's impossible to use genetic mapping techniques to establish an association between the marker and the disease gene.

Question 13

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 cause many serious diseases,including AIDS and cancer.

Question 14

In the current form of dideoxy DNA sequencing,the primer is unlabeled and each dideoxynucleotide is labeled with a different fluorescent marker.This method

Accepted Answer

A) eliminates the need to run sequencing reaction products on a gel. 
B) allows a DNA sequence to be determined from 4 separate sequencing reactions,each run on a separate lane of a gel. 
C) allows a DNA sequence to be determined from one sequencing reaction that is run on a single lane of a gel. 
D) eliminates the need for sophisticated machines to read the output of each sequencing reaction.

Question 15

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

Accepted Answer

A) by injecting engineered viruses into the patient's bloodstream. 
B) by injecting engineered viruses into the patient's bone marrow. 
C) by treating a relative's cultured bone marrow cells with genetically engineered viruses and then injecting these cells into the patient's bone marrow. 
D) by isolating the patient's bone marrow cells,infecting them with genetically engineered viruses,and injecting them back into the patient's bone marrow.

Question 16

The general term for the manipulation of organisms to create products or cure disease is

Accepted Answer

A) recombinant DNA technology. 
B) biotechnology. 
C) gene cloning. 
D) plasmid-mediated transformation.

Question 17

Which of the following is a gene library?

Accepted Answer

A) a collection of DNAs cut by a restriction enzyme 
B) a collection of plasmids cut by a restriction enzyme 
C) a collection of different DNA fragments ligated into plasmids 
D) a collection of genes that have been sequenced from a particular organism 
E) a collection of PCR-amplified DNAs

Question 18

What information is critical to the success of PCR itself?

Accepted Answer

A) 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. 
C) The sequence of restriction enzyme recognition sites in the DNA to be amplified must be known. 
D) The sequence of restriction enzyme recognition sites in the DNA to be amplified and in the plasmid where the amplified DNA fragment will be cloned must be known.

Question 19

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

Accepted Answer

A) plasmid replication. 
B) bacterial cell replication. 
C) Southern blotting. 
D) A and B. 
E) all of the above.

Question 20

Plasmids are used as cloning vectors in genetic engineering.This means that plasmids allow for

Accepted Answer

A) carrying of DNA into a cell and DNA replication. 
B) infection of cells. 
C) DNA replication outside rather than inside cells. 
D) carrying of RNA into a cell and RNA replication.

Exam 19: Analyzing and Engineering Genes