47. The first recombinant DNA molecule was
synthesized in the year__?
A. 1962
C. 1982
B. B. 1972
D. 1992
48. Recombinant plasmids are added to a
bacterial culture that has been pretreated
with
ions?
A. iodine
C. calcium
B magnesium D. ferric
49. Which of the following enzymes in bacteria
are responsible for restricting the growth of
viruses?
A restriction endonuclease
B. topoisomerase
C. gyrase
D. protease
50. Restriction enzymes are named for ?
A. the person who discovered
B. the bacterium they are derived from
C. the viral DNA that they attack.
D. none of the above
51. Some genetic diseases cannot be diagnosed
by changes in restriction sites. Some of these
can
be detected by alle-specific
oligonucleotide probes. These are ?
A. copies of the gene with an altered
sequence so that a restriction site is
inserted.
B. mutagenized copies of a gene.
C. short sequences that will hybridized only
to a specific base sequence
D. PCR-amplified variable numbers of
tandem repeats (VNTRs)
52. In order to insert a foreign gene into a
plasmid both must ?
A. have identical DNA sequences
B. originate from the same type of cell
C. be cut by the same restriction enzyme
D. be of the same length​