26. Which of the following is not true for the microinjection technique that involves the transfer of DNA into protoplast?

A. It is carried out with the help of micromanipulator
B. The recipient cells are immobilized on artificial support or artificially bound to the substrate
C. It employs needle with diameter greater than cell diameter
D. all of the above

27. The right segment of octopine T-DNA (TR) is necessary for

A. enzymes for agropine biosynthesis
B. tumor formation
C. conjugative transfer
D. all of these

28. Opine synthesis is the property

A. conferred to plant cells when it transformed by Agrobacterium tumefaciens
B. determined by the bacteria Agrobacterium tumefaciens
C. both (a) and (b)
D. of normal plant cells

29. Virulent strains of Agrobacterium contain large Ti-plasmids, which are responsible for the DNA transfer and subsequent disease symptoms. It has been shown that Ti-plasmids contain

A. one set of sequence necessary for gene transfer
B. two sets of sequence necessary for gene transfer
C. three sets of sequence necessary for gene transfer
D. four sets of sequence necessary for gene transfer

30. The direct repeats flanking the T-DNA of Agrobacterium tumefaciens are known as

A. cos site
B. flanking sequences
C. border sequences
D. transfer sequences