Name the another name of gene guns method by which an alien DNA can be made to enter plant cell.

Assertion (A): Chromogenic substrates give blue-coloured colonies if the plasmid does not have an insert.

Reason (R): Recombinant colonies produce colour in presence of the chromogenic substrates due to the presence of $\mathrm{\beta }$ galactosidase.
The correct option among the following is:

Following statements describe the characteristics of restriction endonucleases. Identify the incorrect statement.

Write short note on the following :

Gene gun