Download pp Multiple Choice Identify the letter of the choice that best

pp
Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
____
____
____
____
____
____
____
____
1. Enzymes used to cut genes in recombinant research are ____.
a. ligases
b. restriction enzymes
c. transcriptases
d. DNA polymerases
e. replicases
2. Recombinant DNA technology ____.
a. does not use bacteria to make copies for the desired product
b. splices DNAs together
c. is possible only between closely related species
d. does not cut DNA
e. does not involve enzymes
3. Small circular molecules of "extra" DNA in bacteria are called ____.
a. plasmids
b. desmids
c. pilus
d. F-particles
e. transferins
4. Which is not true of plasmids?
a. They are self-reproducing circular molecules of DNA.
b. They are sites for inserting genes for amplification.
c. They cut DNA at particular base sequences, creating sticky end.
d. They may be transferred between different species of bacteria.
e. They may confer the ability to donate genetic material when bacteria conjugate.
5. After being transferred, a plasmid must ____ to form a recombinant DNA molecule.
a. be destroyed
b. be integrated
c. undergo mutation
d. replicate
e. dissolve
6. In order for DNA molecules to undergo recombination, ____.
a. they must be from the same species
b. their strands must separate as in replication
c. they must be cut and spliced at specific nucleotide sequences
d. they must undergo lysis
e. they must be identical
7. The "natural" use of restriction enzymes in nucleus bacteria is to ____.
a. integrate viral DNA
b. destroy viral DNA
c. repair "sticky ends"
d. copy the bacterial genes
e. clone DNA
8. The fragments of chromosomes split by restriction enzymes ____.
a. have fused ends
____
9.
____ 10.
____ 11.
____ 12.
____ 13.
____ 14.
____ 15.
____ 16.
b. have specific recognition sequences of nucleotides
c. form coils
d. form a circle
e. cannot be reassociated
Which is not true of restriction enzymes?
a. They often produce staggered cuts in DNA that are useful in splicing genes.
b. They are like most enzymes in being very specific in their action.
c. They are natural defense mechanisms evolved in bacteria to counteract bacteriophages.
d. They are used along with ligase and plasmids top produce a DNA library.
e. They are sites for inserting genes for amplification.
Restriction enzymes ____.
a. work at recognition sites
b. function only at "sticky ends"
c. produce uniform lengths of DNA
d. function only in genetic laboratories
e. all of the above
Which of the enzymes joins the "sticky ends"?
a. reverse transcriptase
b. restriction enzyme
c. DNA ligase
d. DNA polymerase
e. transferase
The method used to produce single strands of DNA ____.
a. is known as amplification
b. is heating in a solution
c. uses restriction enzymes
d. isolates DNA molecules from the nucleus
e. all of the above
Separation of DNA fragments by gel electrophoresis ____.
a. requires priming
b. is controlled by the size of the fragment
c. is based on the positive charges of phosphate groups
d. is difficult to accomplish
e. needs a detergent to denature proteins
Sanger's method for determining the nucleotide sequence of fragments of a given length utilizes all but which
of the following?
a. radioactively labeled primer
b. single-stranded DNA fragments
c. fluorescent dye
d. DNA polymerase
e. four kinds of nucleotide subunits of DNA (A, T, C, G)
Compared to the chromosome of bacteria, which may have upwards of 5 million base pairs, an episome may
have as few as ____.
a. 2000 bp
b. 1 million bp
c. 1.5 million bp
d. 2 million bp
e. 3 million bp
The F plasmid is important to biotechnologists because it has ____.
____ 17.
____ 18.
____ 19.
____ 20.
____ 21.
____ 22.
____ 23.
____ 24.
a. the conjugation bridge gene
b. the cell wall gene
c. the ligase gene
d. the amplification gene
e. the cell membrane gene
A vector is ____.
a. a recombinant DNA molecule
b. a plasmid; it transfers new genes
c. recombinant DNA fragments
d. a restriction enzyme
e. DNA ligase
If a plasmid has only one site recognized by a restriction enzyme, the DNA can ____.
a. only be inserted at that point
b. not enter the plasmid
c. make more sites available
d. go to another plasmid
e. find another host
Primers serve as ____.
a. starting point for DNA synthesis
b. a stop signal for DNA synthesis
c. a substrate for ligase
d. a locator for sticky ends
e. a spot where endonucleases start
If you ran a gel and the fragment sizes looked like the sizes below, which one migrated the most (went the
farthest)? Fragment lengths
a. ____________________
b. ________________
c. _____________
d. __________
e. _______
DNA in plants ____.
a. has a different chemical structure than bacterial DNA
b. contains the same nucleotides as human DNA
c. is found only in the nucleus
d. in general is difficult to sequence
e. cannot be manipulated by humans
The crown gall bacteria in some way ____ the plant cells to continue to divide.
a. convinces
b. transforms
c. bribes
d. ligates
e. deduces
The Ti plasmid stands for ____.
a. tutorial implant
b. tumor inducing
c. temporary
d. independent
e. initiate
Biolistics is used to ____.
____ 25.
____ 26.
____ 27.
____ 28.
____ 29.
____ 30.
____ 31.
a. create a library of DNA
b. cut single stranded DNA
c. mutate genes in a plant cell
d. insert new genes into a plant cell
e. analyze a genome
Plant viruses have ____ as their genetic material, compared to ____for plants.
a. DNA; DNA
b. DNA; RNA
c. RNA; RNA
d. RNA; DNA
e. DNA; Ti
Viruses can be used ____.
a. to inject genes into plants
b. as a source for biochemicals
c. to cut DNA
d. for control of gene expression
e. to recombine genes
Electroporation is based on the idea that ____.
a. you can pass a small current through a protoplast and it creates temporary holes through
which DNA can pass
b. electrical charge will destroy the membrane thereby allowing DNA to bond with a
recombinant DNA
c. protoplasts do not have cell walls
d. bullets can be used to transport DNA through water
e. DNA works better in a cool environment
____ were the first organisms to be transformed by new genes.
a. Viruses
b. Plant cells
c. Animal cells
d. Fungal cells
e. Bacteria
The most valuable products to be exploited from biotechnology are ____.
a. nucleic acids
b. vitamins
c. proteins
d. lipids
e. carbohydrates
The most prevalent protein in the world is ____.
a. insulin
b. ribulose bisphosphate carboxylase
c. ligase
d. mutase
e. restriction endonucleases
Bacillus thuringiensis is a bacteria that ____.
a. makes a toxin that kills insects
b. inserts its genes directly into some crop plants
c. kills tobacco mosaic virus
d. speeds up germination in peas
e. produces crown galls
____ 32. The FlavrSavr tomato can now be shipped ripe because ____.
a. trains are faster and more efficient
b. it has a new gene that blocks senescence
c. it has a thicker skin
d. a new gene slows down its metabolism
e. it was bred through classical genetics
____ 33. Which of the following statements is true?
a. There is no danger involved in recombinant DNA research in humans.
b. There is no danger involved in recombinant DNA research in bacteria.
c. There is no danger in releasing recombinant organisms into the environment.
d. Stringent safety rules make the use of recombinant DNA research possible.
e. It is safe to conduct recombinant DNA research in plants.
____ 34. One of the first successful applications of genetic engineering was the commercial production of ____.
a. clotting factors
b. insulin
c. hemoglobin
d. strawberries
e. carrot seedlings
____ 35. Which of the following statements is false?
a. A plant has been genetically engineered with a bioluminescent gene from fireflies so that
it glows in the dark.
b. Plants that have been generated from cultured cells derived from the same cell are
identical clones.
c. Mutation rates increase in cultured cells.
d. Gene insertions are safer than pesticides because they are target-specific.
e. The insertion of genes into cultured plant cells uses the plasmid of a bacterial pathogen of
plants.
Essay
36. Explain briefly how restriction enzymes work.
37. Why are plasmids important for biotechnology?
38. Name three enzymes that are required for recombinant DNA technology.
39. Explain how the PCR works.
40. Describe the sequence of events that leads to the development of a crown gall tumor.
41. List and briefly describe the techniques that are used to transform plant cells.
42. Discuss how gene manipulation can result in production of new plants.
43. Explain the mechanism of gene silencing using the technique of RNAi.
44. Discuss briefly the major pros and cons of plant biotechnology.
45. Discuss the difference between classical genetics and genetic engineering.