A and B are two different cloning vectors in two different bacterial colonies cultured in chromogenic substrate Bacterial colonies with cloning vector A were colourless, whereas those with B were blue coloured. Explain by giving reasons the cause of difference in colour that appeared.

A plasmid DNA and a linear DNA (both of the same size) have one site for a restriction endonuclease. When cut and separated on agarose gel electrophoresis, plasmid shows one DNA band, while the linear DNA shows two fragments. Explain.

While carrying out a PCR, 'denaturation' step was missed. What will be its effect on the process?

Why do prokaryotes(bacteria) have restriction enzymes but not eukaryotes?

(a) A recombinant vector with a gene of interest inserted within the gene of a-galactosidase enzyme, is introduced into a bacterium. Explain the method that would help in selection of recombinant colonies from non-recombinant ones.
(b) Why is this method of selection referred to as "insertional inactivation" ?

Agrobacterium tumefaciens is called natural genetic engineer. It infects only dicot plants. Unfortunately, many important crop plants, including corn, rice, and wheat, are monocots and thus could not be easily transfected using this bacterium. Scientists discovered that by using certain processes, naked DNA molecules can be introduced into plant cell types that are not susceptible to A. tumefaciens transfection. Explain any two.

Dicot plants do show tumorous growth (crown gall disease) on the stem.
a. Name the microorganism responsible for this growth?
b. What causes the production of tumors?

In Gel electrophoresis, the DNA fragments are placed in wells on a sheet of gelatin and an electric current is applied to the sheet. Based on DNA biochemistry in which side are the wells located? In which direction and why do the fragments migrate?

Match the following

i)What dose the fig shows?
ii)What is the matrix used for the above process?
Iii)Name the chemical compound used for staining?
iv)Name the process for the separation of DNA from the agarose gel.