Page 4 - Assignment-Biotechnology-principles and procedure

15. Recombinant DNA technology vectors are used to transfer a gene of interest in the
host cells. Mention any three features of vectors that are most suitable for this
purpose.
16. Why is “Agrobacterium–mediated genetic engineering transformation” in plants
considered as natural genetic engineering?
17. Observe the given sequence of nitrogenous bases on a DNA fragment and answer the
following question –
5´ – CAGAATTCTTA – 3´
3´ – GTCTTAAGAAT – 5´
(a) Name a restriction enzme which can recognise this DNA sequence.
(b) Write the sequence after digestion.
(c) Why are the ends generated after digestion called sticky ends?
18. A selectable marker is used in the section of recombinants on the basis of their ability
to produce colour in presence of chromogenic substrate.
(a) Mention the name of mechanism involved.
(b) Which enzyme is involved in production of colour?
(c) How is it advantageous over using antibiotic resistant gene as a selectable marker?

E. Long Answer Questions (5 marks each)

19. The development of bioreactors is required to produce large quantities of products.
(a) Give optimum growth conditions used in bioreactors.
(b) Draw a well labelled diagram of simple stirred – tank bioreactor.
(c) How does a simple stirred – tank‟ bioreactor differ from sparged stirred – tank‟
bioreactor.

20. In the given figure, one cycle of polymerase chain reaction is shown –