Genetics Unit 4 Test

Arabidopsis thaliana has one of the smallest genomes among higher plants with a haploid genome size of about 100 million base pairs. If this genome is completely digested with the restriction enzyme NotI that has an eight-base recognition sequence, approximately how many DNA fragments per genome will be produced?

1526

The restriction enzyme Pst1 cleaves phosphodiester bonds between the G and the A nucleotides in its recognition sequence which is 5′ CTGCAG 3′ for one of the two DNA strands. After cutting by Pst1, the resulting DNA fragments will have:

3′ single-stranded overhanging ends (end in a 3′ group).

Which two mRNA structures interact with each other to provide mRNA stability?

5′ cap and 3′ poly(A) tail

A DNA probe with a sequence similar to that of the gene of interest is often used to screen a DNA library. What could you use as a probe if the sequence of the gene of interest is not known?

A. a similar gene from another organism OR B. a synthetic probe, if the encoded amino acid sequence is known

Which technique would be most useful if you were interested in learning about a protein's function and about the proteins with which it interacts?

A. affinity capture B. protein microarray C. mass spectrometry D. structural proteomics All of the above

You are studying a prokaryote that lives in the gut of a termite species. Compared to a free-living prokaryote living in a changing environment, your organism's genome:

A. should be smaller (in number of base pairs). B. should have approximately the same number of genes for basic housekeeping functions. C. should have fewer genes overall. All of the above

The Federal Bureau of Investigation has developed the Combined DNA Index System (CODIS), which is 13 loci that are used to develop DNA fingerprints for crime solving. Which of the following characteristics is FALSE concerning these 13 loci?

Alleles at each locus are analyzed with Southern blotting.

Which of the following would be MOST appropriate for cloning a gene that is 225 kb in size?

BAC

Low levels of glucose lead to all of the following, EXCEPT that:

CAP-cAMP loses its affinity to DNA.

Which of the following mechanisms of gene regulation is unique to eukaryotic cells?

Chromatin Remodeling

Restriction Enzyme A has the recognition sequence 5′CTGCAG3′. Restriction Enzyme B has the recognition sequence 5′GCGC3′. Based on this information, you can infer that:

Enzyme A will cut the genome into fewer pieces than will Enzyme B.

A restriction enzyme that has a long recognition sequence will cut a genome ________ times compared to a restriction enzyme with a shorter recognition sequence.

Fewer

Which of the following is NOT true regarding the field of bioinformatics?

High subscription costs for access to bioinformatics databases make them impractical for students and many researchers.

Which of the following is NOT a required step in genetically engineering bacteria that can produce a human protein?

Insert the human protein into bacteria.

Gene therapy involves transferring desired genes into human cells to treat disease. Which of the following is NOT true about this technology?

It involves transfer of genes into reproductive (germline) cells so that the correction is heritable.

You are studying a human gene encoding a protein that requires posttranslational modification. What feature(s) is important in picking your vector?

It needs to be an expression vector & It needs to be a vector that can replicate in eukaryotic cells.

Which of the following is NOT true regarding DNA gel electrophoresis?

Larger DNA fragments will migrate farther than smaller DNA fragments will.

Regulation of gene activity can occur at several points in the pathway of information flow. Which of the following types of regulation takes place primarily in eukaryotes?

Modification of chromatin

Which of the following is NOT a reason that mutations are important?

Mutations provide genetic stability.

A woman claims that her former boyfriend, Mr. X, is the father of her child. Mr. X maintains that the child's father is Mr. Y and not him. DNA fingerprints of all four persons are shown below. What can be concluded about the child's paternity? (Picture in slides)

Neither Mr. X nor Mr. Y is the father.

Consider the same partial diploid from Question 7 (lacI+ O+ lacZ+ lacY-/lacIS Oc lacZ- lacY+). Under what conditions will this strain make permease?

Only when lactose is presesnt

Gene cloning requires placing the gene of interest into a cloning vector. A good cloning vector must have which of the following?

Selectable markers

The disease Xeroderma pigmentosum results from DNA-repair defects. People with this disease are sensitive to UV light and have atypical skin pigmentation. Thus these people have higher incidences of what other disease?

Skin Cancer

Which of the following is true of transcriptional activator proteins?

Some have acetyltransferase activity

Several new fields of biological investigation have emerged from genome sequencing projects. Which of the following does NOT correctly match a field with its description or goal?

Synthetic Biology: creates from scratch novel genomes and organisms that are going to be released into natural environments.

Which of the following is NOT true regarding impacts of the human genome project?

The human genome project has led to widespread use of genetic tests by health insurers to assess people's risk of developing disease.

To activate the transcription of permease (and the whole lac operon) lactose needs to be present in the cell. How can lactose get in the cell when the permease gene is not activated?

The repressed lac operon is never completely repressed

Which of the following is an advantage of whole-genome shotgun sequencing compared to map-based sequencing?

The shotgun approach is highly automated.

Which is NOT true of transposable elements?

Their movement will not cause mutations.

Which of the following is NOT true regarding the mutagenic nature of transposition?

There is no evidence that transposition is regulated.

Which is NOT true of a genetic map?

They are limited because their construction is dependent upon single-locus traits.

What is the role of insulators in controlling gene expression?

They block the role of enchancers

Which of the following is NOT a potential benefit of using transgenic plants?

They can generate restriction enzyme sites on a foreign gene of interest to be cloned.

Which of the following BEST describes knockout mice?

They have a gene of interest that has been fully disabled.

A person has been arrested and charged for murder. DNA fingerprint analyses were performed on DNA found at the crime scene (left lane) and on DNA from the suspect (right lane). Does this evidence place the person at the scene of the crime? (picture in slides)

This evidence does not prove that the person was at the crime scene, though the person still could have been there.

All of the following are requirements of a bacterial cloning vector EXCEPT:

Ti plasmid.

Which of the following is NOT true regarding the basic components required for a bacterial cloning vector?

Unique restriction enzyme sites allow for pieces of foreign DNA to be inserted into the bacterial plasmid cloning vector that range in size from 20 kb to 50 kb.

What kind of mutation repair does NOT involve the removing and repairing of nucleotides?

base-excision repair

DNA libraries are constructed and screened for genes of interest. If you were interested in identifying genes expressed in cancer cells, why might you choose to use a cDNA library instead of a genomic DNA library?

cDNA library is enriched for genes that are actively transcribed in your cell of interest.

Which of the following chromatin changes will repress gene transcription?

chromatin-remodeling complexes that reposition nucleosomes

The kind of gene whose product interacts with other nucleotide sequences to affect their transcription or translation is a:

constitutive gene

Recombinant DNA technology has led to advances in which of the following?

drug development, crop development, disease diagnosis and treatment *** all of the above

The genomes of over 100 eukaryotes have now been sequenced. Comparison of these sequenced genomes has revealed that:

eukaryotic genomes contain multiple copies of many genes.

Which of the following is a product that has resulted or improved because of recombinant DNA technology?

genetically engineered crops & specialized microorganisms & pharmaceuticals such as insulin and human growth hormone & genetically engineered animals

Compared to the original Sanger method of DNA sequencing, next generation sequencing methodologies:

have made sequencing faster & allow hundreds of thousands to millions of DNA fragments to be simultaneously sequenced.

A(n) _______ error occurs when a mismatched base has been incorporated into a newly synthesized nucleotide chain. When this DNA is copied, this error leads to a(n) _____ error.

incorporated; replication.

A new mutagen is able to cause frameshift mutations. Which kind of mutagen would be capable of reversing this mutation?

intercalating agent

A mutation in gene X overrides the effect of a previous mutation in gene Y and restores wild-type phenotype. The mutation in gene X is called a(n):

intergenic suppressor mutation.

Positional cloning of a gene of interest requires that:

its map position on a chromosome is known.

When present in small amounts in sequencing reactions, dideoxyribonucleoside triphosphates (ddNTPs) terminate the sequencing reaction at different positions in the growing DNA strands. ddNTPs stop a sequencing reaction because they:

lack a hydroxyl (-OH) group at their 3′ end.

What technique would be most useful and efficient in comparing the different gene-expression patterns among developmental stages of mouse embryogenesis?

microarray analysis

Which of the following types of gene mutation in a protein-coding gene usually have the least severe (i.e., deleterious) phenotype?

missense substitutions

Consider the following partial diploid strain of E coli: lacI+ O+ lacZ+ lacY-/lacIS Oc lacZ- lacY+. Under what conditions will this strain make β-galactocidase?

never

Restriction fragment length polymorphism (RFLP) is a technique used to map genes. RFLP takes advantage of variations in the pattern of fragments produced by restriction enzymes. What types of mutations will cause fragment pattern differences?

only mutations that occur at restriction sites in the genome

A typical operon contains several regions. Which region is where a regulator protein binds?

operator

The human genome contains three genes for enolase (a, b, g), whereas yeast contains just one gene for enolase. The three human enolase genes are __________ of each other, whereas the human and yeast enolase genes are __________ of each other.

paralogs; orthologs

To clone a very large piece of DNA (over 100,000 base pairs), which of the following bacterial cloning vectors should be used? A. plasmid B. phage lambda C. cosmid D. bacterial artificial chromosome E. All of the above can be used to clone any size of DNA.

plasmid, phage lambda, cosmid,bacterial artificial chromosome all the above can be used to clone any size of DNA

From constructing mice with large deletions of gene deserts, researchers were able to conclude that gene deserts function in ____________.

processes not yet known

What is an advantage of the mouse as a model genetic organism?

rapid reproduction & easy to maintain in the laboratory & closely related to humans & small size

Which of the following mapping methods has the lowest resolution?

recombination frequency

What kind of transposition causes an increase in the copy number of transposable elements?

replicative transposition

For a(n) __________ operon, transcription normally takes place, and it is turned off by a(n) _________.

repressible; repressor

1. A researcher has made a cDNA library in an expression vector and wants to identify the clone for a gene that has not been sequenced but for which the amino acid sequence of the encoded protein is known. What could the researcher use as a probe?

similar gene from another organism & synthetic probe containing all possible codons for the encoded protein & an antibody that recognizes the encoded protein

Gel electrophoresis can be used to separate DNAs on the basis of:

size.

siRNA and miRNA inhibit gene expression by all of the following EXCEPT:

stabilizing translation machinery

Which is NOT one of the factors that influences calculated mutation rates?

the probability of surviving a mutation

All of the following are true of single nucleotide polymorphisms (SNPs) EXCEPT:

they are rare among persons of the same ethnic group.

The trp operon repressor has two binding sites. In sequential order, what two things bind the repressor?

tryptophan, DNA