Role of host-vector system is crucial for making a recombinant DNA molecule. Which of the following cannot function as vector in r-DNA technology?

Correct option is C

Correct Answer: (c)
Explanation:
E. coli acts as host cell, not vector. Vectors are DNA carriers that transport foreign genes.
Information Booster:
A vector must replicate independently.
It should carry selectable markers.
λ–Phage is widely used for bacterial cloning.
Ti plasmid is used for plant gene transfer.
YAC can clone very large DNA fragments.
Additional Information (Incorrect Options):
(a) YAC → works as vector.
(b) λ–Phage → common cloning vector.
(d) Ti plasmid → plant transformation vector.