Chapter 20 - Biotechnology - Multiple Choice Flashcards
The role of restriction enzymes in DNA technology is to
a. provide a vector for the transfer of recombinant DNA.
b. produce cDNA from mRNA.
c. produce a cut (usually staggered) at specific restricion sites on DNA.
d. reseal “sticky ends” after base pairing of complementary bases.
e. denature DNA into single trands that can hybridize with complementary sequences.
c. produce a cut (usually staggered) at specific restricion sites on DNA.
The segment of DNA shown in the image has restriction sites I and II, which create restriction fragments a, b, and c. Which of the following gels produced by eletrophoresis would represent the separation and identity of these fragments?
b.
Yeast has become important in genetic engineering because it
a. has RNA splicing machinery.
b. has plasmids that can be genetically engineered.
c. allows the study of eukaryotic gene regulation and expression.
d. grows readily and rapidly in the laboratory.
e. does all of the above.
e. does all of the above.
Which of the following DNA sequences wuold most likely be a restriction site?
a. AACCGG
TTGGCC
b. GGTTGG
CCAACC
c. AAGG
TTCC
d. AATTCCGG
TTAAGGCC
e. GAATTC
CTTAAG
e. GAATTC
CTTAAG
Which of the following is not true of adult stem cells?
a. They have been found not only in bone marrow, but also in other tissues, including the adult brain.
b. Although more difficult to grow than enbryonic stem cells, they have been successfully grown in culture and made to differentiate into specialized cells.
c. They are differentiated cells that can be induced to dedifferentiate and become totipotent.
d. They are capable of developing into several but not all types of cells under appropriate conditions.
e. These relatively unspecialized cells continually reproduce themselves.
c. They are differentiated cells that can be induced to dedifferentiate and become totipotent.
Petroleum-lysing bacteria are being engineered for the treatment of oil spills. What is the most realistic danger of these bacteria to the environment?
a. mutations leading to the production of a strain pathogenic to humans
b. extinction of natural microbes due to the competitive advantage of the “petro-bacterium”’
c. destruction of natural oil deposits
d. poisoning of the food chain
e. contamination of the water
c. destruction of natural oil deposits
You are attempting to introduce a gene that imparts larval moth resistance to bean plants. Which of the following vectors are you most likely to use?
a. phage DNA
b. E. coli plasmid
c. Ti plasmid
d. yeast plasmid
e. bacterial artificial chromosome
c. Ti plasmid
An attenuated virus
a. is a virus that is nonpathogenic.
b. is an elongated viral particle.
c. can transfer recombinant DNA to other viruses.
d. will not produce an immune response.
e. is made with cDNA.
a. is a virus that is nonpathogenic.
Which of the following is a difficulty in getting prokaryotic cells to express eukaryotic genes?
a. The signals that control gene expression are different and prokaryotic promoter regions must be added to the vector.
b. The genetic code differs because prokaryotes substitute the base uracil for thymine.
c. Prokaryotic cells cannot transcribe introns because their genes do not have them.
d. The ribosomes of prokaryotes are not large enough to handle long eukaryotic genes.
e. The RNA splicing enzymes of bacteria work differently from those of eukaryotes.
a. The signals that control gene expression are different and prokaryotic promoter regions must be added to the vector.
Complementary DNA does not create as complete a library of genes as the shotgun approach because
a. it has eliminated introns from the genes.
b. a cell produces mRNA for only a small portion of its genes.
c. the shotgun approach produces more restriction fragments.
d. cDNA is not as easily integrated into plasmids.
e. reverse transcriptase cannot transcribe introns.
b. a cell produces mRNA for only a small portion of its genes.
Which of the following is not true of restriction sites?
a. Modification by methylation of bases within them prevents restriction of bacterial DNA.
b. They are usually symmetrical sequences of four to eight nucleotides.
c. They signal the attachment of RNA polymerase.
d. Each restriction site is cut by a specific restriction enzyme.
e. Cutting a restriction site in the middle of a functional and identifiable gene is used to screen clones that have taken up foreign DNA.
c. They signal the attachment of RNA polymerase.
Which is the first enzyme used in the production of cDNA?
a. restriction enzyme
b. reverse transcriptase
c. ligase
d. DNA polymerase
e. RNA polymerase
b. reverse transcriptase
Which enzyme is used in the polymerase chain reaction?
a. restriction enzyme
b. reverse transcriptase
c. ligase
d. DNA polymerase
e. RNA polymerase
d. DNA polymerase
Which is the first enzyme used in the production of RFLPs?
a. restriction enzyme
b. reverse transcriptase
c. ligase
d. DNA polymerase
e. RNA polymerase
a. restriction enzyme
A plasmid has two antibiotic resistance genes, one for ampicillin and for teracycline. It is trated with a restriction enzyme that cuts in the middle of the ampicillin gene. DNA fragments containing a human globin gene were cut with the same enzyme. The plasmids and fragments are mixed, treated with ligase, and used to transform bacterial cells. Clones that have taken up the recombinant DNA are the ones that
a. are blue and can grow on plates with both antibiotics.
b. can grow on plates with ampicillin but not with tetracycline.
c. can grow on plates with tetracycline but not with ampicillin.
d. cannot grow with any antibiotics.
e. can grow on plates with tetracycline and are blue.
c. can grow on plates with tetracycline but not with ampicillin.
This restriction fragment contains a gene whose recessive allele is lethal. The normal allele has restriction sites for the restriction enzyme PSTI at sites I and II. The recessive allele lacks restricion site I. An individual who had a sister with the lethal trait is being tested to determine if he is a carrier of that allele. Indicate which of these band patterns would be produced on a gel if he is a carrier (heterozygous for the gene)?
d.
