5 Written questions
5 Matching questions
- 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?
A) to attach the DNA fragments to a permanent substrate
B) to prepare the DNA for digestion with restriction enzymes
C) to separate the two complementary DNA strands
D) to separate out the PCRs
E) to transfer only the DNA that is of interest
- A 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?
A) a human chromosome
B) a bacterial plasmid
C) a YAC with appropriate cellular enzymes
D) BAC to accommodate the size of the sequence
E) a modified bacteriophage
- Plants are more readily manipulated by genetic engineering than are animals because
A) plant genes do not contain introns.
B) genes can be inserted into plant cells by microinjection.
C) a somatic plant cell can often give rise to a complete plant.
D) more vectors are available for transferring recombinant DNA into plant cells.
E) plant cells have larger nuclei.
- A mutation that inactivates the regulatory gene of a repressible operon in an E. coli cell would result in
A) irreversible binding of the repressor to the operator.
B) continuous transcription of the structural gene controlled by that regulator.
C) inactivation of RNA polymerase by alteration of its active site.
D) complete inhibition of transcription of the structural gene controlled by that regulator.
E) continuous translation of the mRNA because of alteration of its structure.
- Which of the following sequences in double-stranded DNA is most likely to be recognized as a cutting site for a restriction enzyme?
- a A) to attach the DNA fragments to a permanent substrate
- b B) continuous transcripton of the structural gene controlled by that regulator
- c B) GGCC
- d C) a YAC with appropriate cellular enzymes
- e C) a somatic plant cell can often give rise to a complete plant
5 Multiple choice questions
- E) The drug inhibits the specific thymine kinase receptor.
- A) ribosomes, tRNAs, amino acids, and GTP
- B) interference with viral replication
- C) The RNA is only translated into a single long polypeptide, which is then cleaved into shorter ones
- E) a large number of phages are released at a time
5 True/False questions
Some viruses can be crystallized and their structures analyzed. One such virus isDesmodium, or yellow mottle virus, which infects beans. This is a member of the tymovirus group and has a single-stranded RNA genome of ~6,300 nucleotides. Its virion is 25—30 nm in diameter, and is made up of 180 copies of a single capsid protein that self-associate to form each capsomere, which has icosahedral symmetry with 20 facets.
If this virus has a positive RNA strand as its genome, it begins the infection by using this strand as mRNA. Therefore, which of the following do you expect to be able to measure?
A) translation rate
B) formation of new transcription factors
C) accumulation of new ribosomes D) transcription rate
E) replication rate → C) mutation of existing viruses, the spread of existing viruses to new host species, and the spread of existing viruses more widely within their host species
A researcher introduces double-stranded RNA into a culture of mammalian cells, and can identify its location or that of its smaller subsections experimentally, using a fluorescent probe. Within the first quarter hour, the researcher sees that the intact RNA is found in the cells. After 3 hours, she is not surprised to find that
A) the double-stranded RNA binds to mRNAs to prevent translation.
B) the double-stranded RNA replicates itself.
C) the RNA is degraded by 5' and 3' exonucleases.
D) Dicer enzyme has reduced it to smaller double-stranded pieces.
E) the double-stranded RNA binds to tRNAs to prevent translation. → A) to decrease the production from a harmful gain-of-function mutated gene
RNAi methodology uses double-stranded pieces of RNA to trigger a breakdown or blocking of mRNA. For which of the following might it more possibly be useful?
A) to decrease the production from a harmful gain-of-function mutated gene
B) to raise the rate of production of a needed digestive enzyme
C) to raise the concentration of a desired protein
D) to destroy an unwanted allele in a homozygous individual
E) to form a knockout organism that will not pass the deleted sequence to its progeny → D) Dicer enzyme has reduced it to smaller double-stranded pieces
Use the following information to answer the following questions.
InDrosophila after ~100 minutes postfertilization, the embryo looks like the following diagram, with all nuclei having moved to the periphery and, subsequently, four of the nuclei being sequestered at the posterior end. The four sequestered cells at one end are most probably destined to become
C) the legs of the adult fly.
D) the germ cells of the adult.
E) wing primordial. → C) organismal cloning
The herpes viruses are very important enveloped DNA viruses that cause disease in all vertebrate species and in some invertebrates such as oysters. Some of the human ones are herpes simplex (HSV) I and II, causing facial and genital lesions, and the varicella-zoster (VSV), causing chicken pox and shingles. Each of these three actively infect nervous tissue. Primary infections are fairly mild, but the virus is not then cleared from the host; rather, viral genomes are maintained in cells in a latent phase. The virus can then reactivate, replicate again, and be infectious to others.
In order to be able to remain latent in an infected live cell, HSV must be able to shut down what process?
A) all immune responses
B) transcription of viral genes
C) DNA replication
D) apoptosis of a virally infected cell
E) interaction with histones → C) mutation of existing viruses, the spread of existing viruses to new host species, and the spread of existing viruses more widely within their host species