- an advantage of using yeasts rather than bacteria as
recipient cells for the recombinant DNa of eukaryotes
is that yeasts can
(a) produce restriction enzymes
(b) excise introns from the rNa transcript
(c) remove methyl group
(d) reproduce more rapidly.
- Study the given figure carefully and select the correct
statements regarding this
I. It represents typical agarose gel electrophoresis
showing differential migration of DNa fragments.
II. Lane 1 contains digested and undigested DNa
fragments.
III. Lanes 2 to 4 contains digested DNa fragments.
IV. Smallest DNa bands are present at (a) position and
largest DNa bands are present at (b) position.
(a) I and III (b) I, II and IV
(c) II and III (d) III and IV
- Identify and match the labelled items, a, b, C, D, e, f and
G in the diagram below from the list I-VII given with
components.
20. Which of the following characteristics is undesirable in
cloning vectors used in genetic engineering?
(a) Control their own replication
(b) High copy number
(c) Small in size
(d) Vulnerable at several sites to a restriction enzyme.
I. DNa polymerase
II. plasmid
III. plasmid with ‘sticky ends’
IV. DNa ligase
V. restriction endonuclease
VI. recombinant DNa
VII. reverse transcriptase
The correct components are
A B C D E F G
(a) VII I II V III IV VI
(b) VII VI V IV III II I
(c) VII V III I II IV VI
(d) I II IV VI III V VII
- Palaeontologists unearthed a human skull during
excavation. a small fragment of the scalp tissue was still
attached to it. Only little DNa could be extracted from
it. If the genes of the ancient man need to be analyzed,
the best way of getting sufficient amount of DNa from
this extract is
(a) by hybridizing the DNa with a DNa probe
(b) by subjecting the DNa to polymerase chain reaction
(c) by subjecting the DNa to gel electrophoresis
(d) by treating the DNa with restriction endonucleases.
- restriction enzymes present in several micro-organisms
cut foreign DNa at specific sites and destroy them. The
enzymes do not destroy the host DNa because
(a) the cellular DNa does not have the specific sites
(b) the susceptible specific sites are masked by proteins
(c) the restriction enzyme susceptible sites are modi-
fied by cellular enzymes
(d) the restriction enzymes and DNa occupy different
compartments.
